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CONTENTS
PUBLISHER
Danny J. Salchert OFFICE MANAGER
Anita Salchert ASSOCIATE PUBLISHER
Jerry DiChiara jerryd@epsmag.net CREATIVE DIRECTOR
Derek Gaylard CONTRIBUTING WRITERS
Martin Bambach • Jeff Jowett Gordon Smith CIRCULATION DIRECTOR
Pam Fulmer
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PRESIDENT
Danny J. Salchert
FEATURES 6 Finding a Way Through the Guarantee Maze By Martin Bambach
18 24
Applications of Clamp-on Ground Testers By Jeff Jowett
The Data Logger Buying Decision By Gordon Smith
16 DEPARTMENTS 32 34 40
Industry News Product Focus Ad Index
ON THE COVER Photo courtesy of Conergy AG
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Electrical Products & Solutions • January 2013
Executive and Advertising Offices 3591 Cahaba Beach Road Birmingham, AL 35242 toll free: 800.981.4541 phone: 205.981.4541 fax: 205.981.4544 www.epsmag.net • danny@epsmag.net Electrical Products & Solutions™ is published twelve times a year on a monthly basis by ABD Communications, Inc., 3591 Cahaba Beach Road, Birmingham, Alabama, 35242, USA. Electrical Products & Solutions™ is distributed free to qualified subscribers. Non-qualified subscription rates are $57.00 per year in the U.S. and Canada and $84.00 per year for foreign subscribers (surface mail). U.S. Postage paid at Birmingham, Alabama and additional mailing offices. Electrical Products & Solutions™ is distributed to qualified readers in the electrical contracting industry. Publisher is not liable for all content (including editorial and illustrations provided by advertisers) of advertisements published and does not accept responsibility for any claims made against the publisher. It is the advertiser’s or agency’s responsibility to obtain appropriate releases on any item or individuals pictured in an advertisement. Reproduction of this magazine in whole or in part is prohibited without prior written permission from the publisher. POSTMASTER: Send address changes to ABD Communications, Inc., P.O. Box 382885 Birmingham, Alabama 35238-2885
PRINTED IN THE USA
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FEATURE • Conergy AG
Finding a Way Through the Guarantee Maze
By Martin Bambach, Senior Manager Product Assessment, Conergy AG
W
arranties, product and performance guarantees, guarantee terms and conditions – what are the differences, what rights do solar installation operators have in the event of damage and what kind of compensation are they entitled to? What constitute good guarantee terms and conditions? A solar installation is one of the safest investments. But only as long as there are no damage or guarantee issues, according to consumer protection groups. They are increasingly voicing complaints that guarantees and guarantee services provided by solar module manufacturers are often onesided and customer-unfriendly. There is either a lack of transparency or the small print is incomprehensible and the customer gets lost in a guarantee maze. By law, the customer is entitled to a two-year warranty as a minimum. This is stipulated in EU warranty directive 1999/44/EC. Here the same rules apply to all manufacturers, whether they make fridges, cars, TVs or solar modules. If there is a defect or fault with the product within the two-year warranty period, the manufacture must either repair it, reimburse the price paid or replace it. The user may also claim the right to withdraw from
6
the purchase contract during this period. Any guarantees that go beyond this statutory warranty are voluntary undertakings on the part of the manufacturer, that is to say voluntary extensions of the warranty. And here the devil is often in the detail –
Electrical Products & Solutions • January 2013
or more exactly in the guarantee terms and conditions. In the solar industry, many manufacturers today offer 10-year, or even 12year, product guarantees – something the buyers of TVs and fridges Continued on page 8
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FEATURE • Conergy AG
Continued from page 6
can only dream about and would never really find. Admittedly most household appliances are seldom designed to have a long-term lifecycle of more than 20 years. During the lifetime of the product guarantee, the manufacturer warrants that his modules will be free from production-related defects or any defects resulting from materials used or workmanship. Prerequisites for the validity of the warranty include the fact that the module must have been correctly installed in accordance with the installation and operating instructions. There are, however, also a large number of exclusions and rules, which can lead to the guarantee being terminated if they are not followed. The guarantee terms and conditions offered by manufacturers can often vary significantly in terms of details, rules and responsibilities. In general terms, it can be said that the more detail there is the better, for then both sides know where they stand and which rules need to be followed. But even then it is necessary to read the small print very carefully with some manufacturers. They often use weird and wonderful exclusion clauses as a way of getting out of the guarantee. For example, some manufacturer’s modules seem to not include plugs or cables. In such cases the product guarantee for the module would not be triggered in the event that the plug is faulty or the cable has not been properly handled so that the module no longer works. Today, comprehensive performance guarantees are available, either of the staged or linear variety. The staged variety normally guarantees around 90 per-
8
cent of the nominal or minimum performance during the first 10 years and 80 percent during the following 15 years. A linear performance guarantee tends to be more customer-friendly and guarantees that any annual drop-off in performance during the first year or any subsequent years does not exceed a specific percentage. The advantage of this type of guarantee is that the customer does not run the risk of falling into a so-called “performance hole” immediately after commissioning. With the staged model, the performance guarantee will only be triggered in the first year following commissioning if the module performance drops below 90% of the nominal or minimum performance level. With this type of voluntary comprehensive manufacturer’s guarantee, investors and installation users generally believe that they are well protected. Despite this, or maybe even because of this, there have been growing complaints from consumer protection groups. These complaints are generally not about the guarantees themselves, but about the terms and conditions of many of the guarantees. In many cases the terms and conditions are incomprehensible, not transparent and not very customer-friendly. Some are so complicated and include so many special clauses and exclusion clauses it is as though they have been deliberately written to make them impossible to understand. As a result, investors end up feeling un-
Electrical Products & Solutions • January 2013
certain and that they cannot rely on a clear set of rules. It has been shown that there can be huge differences between the apparent promises made in guarantees and reality, especially because of the small print, and users can often end up having to bear the full costs, without realising beforehand that they were liable for them. And it generally makes no difference whether we are talking about a private customer with an installation on the roof or an investor with a whole solar park. There are seldom differences when it comes to warranties and guarantees, except in terms of the sums invested and therefore the risks involved. An investor with a large installation runs a higher risk than a user with a small roof installation because of the much greater number of modules that could become faulty. However, the small installation may often involve more ancillary costs, as the removal of a module can be more expensive than with a solar park-type installation. Nevertheless, the guarantees covering the solar modules are identical in both cases and the cost of replacing a module also falls predominantly on the installation user in both cases. It is precisely this type of one-sided provision that are disliked by consumer protection groups. They are calling for a better service on the part of the manufacturers rather than these hidden costs for Continued on page 12 customers, investors
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FEATURE • Conergy AG
Continued from page 8
or installation operators. It is true that in reality the financial burden is often not shared equally. In many guarantee terms and conditions currently on the market, it is stipulated that the installation operator must bear all the ancillary costs involved in a guarantee case, including, for example, the cost of testing and obtaining an expert’s opinion, transport, scaffolding and installation. But first he has to prove that there is a guarantee claim in the first place. And for this the operator must bear all the costs incurred in carrying out the necessary tests, either by using an engineer on site or an institute that runs standard tests. In the latter case, the module has to be removed from the roof and transported to the institute, without any certainty that the damage or defect that has been identified will actually be recognised. Often it is the manufacturer alone who decides whether or not there is any damage or defect. Objective testing institutes are seldom recognised and in some cases even completely ignored. Even if
the damage or defect is accepted, the module must then often be sent to the manufacturer at the customer’s expense, and more often than not the manufacturer
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Electrical Products & Solutions • January 2013
is not “just around the corner” but possibly in another country. To give a worstcase scenario: the end customer not only pays for all the testing, Continued on page 14
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FEATURE • Conergy AG
Continued from page 12
installation and labour costs, but also has to pay for the module to be transported to China. During this period, and it is often impossible to predict just how long this will be, the installation’s overall output will also be lower. With foreign modules, there is the added complication that it is often the law of the land in which the module is manufactured that is valid and not German law. It is often the case that guarantee claims dealt with under Asian law result in no compensation being paid to the customer. This is a risk that many users do not realise they are taking until after the claim actually arises. Mostly, all he can hope for is to be dealt with fairly, but this is often not the case. The manufacturer must normally bear the cost of repairing the module, delivering a new or alternative module or, alternatively, refunding the market price or residual value. Even where there is a proven warranty case, the manufacturer is normally in a position to decide which of these three compensation options to go for – and this is not always to the customer’s advantage. If the module is repaired, the customer ends up with the installation being returned to its original state. The same is true if the manufacturer provides a similar replacement module. The problems start for the installation operator when it is no longer possible to provide this type of module. The new module on offer may not exactly match the installation because it is not the same colour or size, and, in the worst case, it may be that it cannot be fitted to the installation at all. The ridiculous practice of providing two 185 watt modules in place of one 240 watt module is also not unusual in today’s warranty world – even if the operator has no space for two modules instead of one on his house or company roof and the modules don’t fit into the installation’s electrical set-up. This would be the equivalent of a sports car manufacturer delivering two smaller cars onto your driveway in a guarantee case, while claiming that together the two cars have similar or even greater horsepower than the sports car under warranty. The worst case, however, is if the manufacturer simply refunds the residual value of the module. In this case the performance and power output of the instal14
lation will remain at a lower level and the operator will receive a reduced feed-in tariff, not to mention the fact that the roof installation will no longer look nice. Most existing solar module guarantees are also not transferable, or only transferable to a limited extent. According to the terms and conditions of many guarantees, they apply to the individual and not the product itself. This means that if a house owner wants to sell his house, complete with photovoltaic installation, then all the guarantees pertaining to the solar modules will become null and void, and as a result, the installation will be worth substantially less. The same is true if a company decides to move to a new building elsewhere. Very few guarantees are transferable and apply to the product itself and remain unchanged in the event of the sale of the house. In these cases, the guarantee is transferred 1:1 to the new owner. The same is true in the case of a roof being renovated. Even if the solar modules are removed correctly and then re-mounted correctly in exactly the same place afterwards, most guarantees today would become null and void. What quickly becomes clear when you take these small print issues into account is that the claims process is likely to take time – from verifying the problem, through to providing comprehensive data about the installation and getting a decision on the likely outcome. And it is precisely in this instance that time is money – money that the installation operator or in-
Electrical Products & Solutions • January 2013
vestor is going to lose. Depending on the time of year, and the importance of the defective module to the installation’s overall performance, significant losses can quickly mount up and will almost never be balanced out by payments from the module manufacturer. The only real remedy for this problem is to have an output insurance and to have a strict and efficient claims process where users have access to a contact in their own country or, even better, can speak to the installer or manufacturer direct; and where as much of the installation data as possible is already known, for example by registering the data as soon as the installation is commissioned. Like that there is no need for a long and time-consuming hunt for serial numbers, module types and installation protocols when a problem arises. If all the necessary data is registered in the beginning, the whole claims process can be speeded up, which would save all those involved valuable time, and therefore money, but also a lot of stress. Installation operators are more comprehensively protected if they also have an additional output insurance policy, which compensates them in the event of a drop in installation output up to a certain percentage. This ensures that their investment is protected throughout the whole claims process, even in the event of the installation ceasing to function completely. For larger installations, in particular, this can represent genuine added value. However, it is also worth checking Continued on page 16
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FEATURE • Conergy AG
Continued from page 14
the small print in output insurance policies, as there are often big differences in terms of the materialisation of the risk, cover modalities, the amount of cover or the operator’s excess contributions. Let’s get back to the guarantees. Because of the many sticking points to be found in the small print, the guarantee terms and conditions offered by the industry as a whole are hardly customer-friendly. What is clear, is that this issue, as with so many service issues, is going to become much more important in the future. So why is it that, on this issue, so many module manufacturers seem content to offer so little in terms of customer service and fairness, instead of trying to offer more? The main prerequisite for offering fair guarantees is being able to provide high-quality products so that there is a low instance of product failures and claims. The learning curve in the photovoltaic industry is very steep, and many of the earlier ‘rookie’ mistakes that led to defects in recent years, have now been stamped
out by the manufacturers. However, many manufacturers are still reluctant to accept the risk on their own products, even though they offer them with long-term product and performance guarantees. Even though service and customer-friendliness are becoming increasingly important in the solar industry. But there is light at the end of the tunnel. Since February,
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Electrical Products & Solutions • January 2013
Conergy, the Hamburg-based system provider, has for the first time been offering comprehensive – and so far unique – guarantee terms and conditions for modules manufactured in-house. It is easy to see how this is now possible. Extensive quality controls ensure that the average claims percentage for their modules are significantly below the industry average at just 0.0045%. On this basis, it is easy to calculate the risk, both for the manufacturer and for the customer. There are not likely to be many claims. If there is a claim, the company will bear the costs of testing and replacement up to a fixed amount, will guarantee a replacement that is the same as the original, will accept the opinion of objective testing institutes and will allow the transfer of guarantees to third parties. By registering the installation data in advance, all the details needed to ensure that the claim progresses smoothly will already be on hand and the customer will be able to rely on the promises made in the guarantee. ❏
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FEATURE • Megger
Applications of Clamp-on Ground Testers
By Jeff Jowett
C
lamp-on ground testers appeared on the market a little over twenty years ago, and have come full circle from a novelty to a valuable addition to the tool kit. Initially, they were unreliable, criticized, and in some applications barred from use. Problems existed in both the technology and the application. The evolution of electronics and knowledge gained through field experience have largely eliminated the former problem. Education and training effectively solve the latter. First-generation clamp-ons were prone to erratic readings. Studies conducted headto-head with conventional ground testers found poor agreement between the readings produced by the two technologies. How the tester was being used had something to do with this, and will be covered, but the principle issue had to do with shielding. Although to the eye it presents a single jaw mechanism that resembles a clamp-on ammeter, the ground tester is more complex. The jaws actually contain two windings, one for current and one for voltage, that take the place of the two test circuits and movable probes employed by conventional ground testers. Shielding must prevent the windings from exhibiting cross-talk, as well as picking up interference from extraneous sources. First-generation testers did this poorly, hence the propensity to produce erratic and unstable readings. In spite of this, the instruments were widely used and in fact became a notable market success. Why? Because they are easy to use. Clampons require little time and little training, a stark con-
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trast to labor-intensive and procedure-reliant conventional testers. Field workers found them just too convenient and evidently put up with the instabilities. But more demanding industries, such as the mining industry, were far less tolerant and in some cases banned them. Meanwhile, engineers at the instrument manufacturers were learning from the feedback and working to eliminate complaints. Circa ’97-’98, the second generation of instrumentation was launched, with improved shielding that eliminates the cross-talk and brings noise influence within tolerable limits. Whenever there is involvement with an issue of this sort, check the vintage of the instrumentation and the documentation. Modern instruments should not be a problem. Effective noise suppression is an art as well as a science, and manufacturers zealously guard their secrets. But checking the manufacturer’s specifications on noise suppression is a good idea. The least noiseprotected designs can slow down an operation through excessive interference. Clamp-on operation is readily understood. And it should be understood in order to effectively use the instrument. Its ease of operation can be a double-edged sword. Conventional ground testers are not intuitive and almost force the operator to gain at least a basic understanding of their operation. Clamp-ons don’t. An actual study conducted by a lightning protection service discovered a substantial proportion of clamp-on users merely clamping any convenient point and walking away with the reading. These were in many cases not actual ground re-
Electrical Products & Solutions • January 2013
sistance measurements, as will be explained. The operator should know that the tester induces a current on the clamped rod or conductor, holds the voltage constant and measures current flow around the circuit in order to calculate resistance. It’s pure Ohm’s Law: R=V/I. But note what is happening here. You want the current to travel through the soil in order to give you a ground resistance measurement. There are two generic conditions that hamper or alter this basic operation. They can be viewed as the fundamental electrical problems of “shorts” and “opens”. An “open” means no current flow. Obviously, the tester cannot make a measurement, and will display this condition, usually as an over-range. For current to flow, there must be a continuous path back to the jaws of the clamp. With a conventional tester, the operator decides on this and defines it, by means of placing a current probe in the ground. This is more work, but it is also more definitive (Fig. 1). The clamp-on “makes the decision” for itself, that is, by finding the “path of least resistance.” Normally, this is conveniently provided by the grounded neutral of the utility. Test current travels through the soil to the utility grounding electrodes, through the grounded neutral to the Continued on page 20
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FEATURE • Megger
Continued from page 18
FIGURE 1
service entrance, and then via the jumper from the neutral to ground bus back to the tester (Fig. 2). What is measured is the series loop resistance. The method works because it relies on the utility to provide a low resistance that contributes only a negligible error to the measurement. Most of what is measured is the resistance of the earth. The slight error is to the good because, of course, you want ground resistance to be under some specified value. A slight additional error, therefore, means that the actual ground resistance is a bit better than the measured value. An added small benefit here is that ground resistance is quite dependent on local soil conditions and so can be expected to vary somewhat around the calendar. A value that is dead on spec, then, might be expected to drift a bit out of spec at times. It’s added insurance to have a safety margin. If the grounding electrode under test is connected to the electrical system, it can generally be expected that a good return path exists and the measurement is reliable. But this requirement completely eliminates the important function of commissioning new systems. Clamp-on cannot test an isolated ground electrode, like a single rod with nothing attached. No return current path exists; it reads as an open. Indeed, temporary returns can be rigged, as by stringing a wire out to a fence post or the like, but such measures defeat the utilitarian purpose of using a clamp-on to begin with. Furthermore, the error introduced by the return connection may be in excess of tolerable limits. Specialized applications like the test20
FIGURE 2
ing of temporary grounds at accident scenes or for off-loading volatile liquids are similarly defeated. Conventional testers meet these situations because the operator deliberately sets up the current path with the use of probes driven into the soil, as has been mentioned. An interesting comparison can be made to an established method that often appears in the literature by the colorful name “dead earth method”. All that is meant by the term “dead earth” is that the method employs a grounding element that is not a part of the electrical system, hence “dead”. This method is only used under extremely difficult physical conditions, such as congested urban areas with no open dirt and no room to operate. A conventional tester has its terminals shunted into a two-terminal configuration and long leads are run to the test ground and some remote pre-existing ground point presumed to have low resistance. This is most often the water pipe system, but could be something like a deep-driven metal fence post (Fig. 3). The tester acts essentially like an AC multimeter; AC because ground testers typically operate with square-wave signals in order to avoid interference from the many noise sources in the soil. Test current travels from one terminal to the test ground, through the soil to the remote return point and back FIGURE 3
Electrical Products & Solutions • January 2013
through the long lead to the tester. A series loop resistance is measured. Note that this is essentially how a clampon operates, but with two huge improvements; the purely physical advantage of not requiring leads and probes, and the electrical advantage of the multi-grounded utility providing a low-resistance return. With the dead earth method, the single-point return can contribute a large and unknown error to the measurement. The success of the method relies on this error being negligible, but as with temporary returns mentioned above, that may not be. Dead earth is useful only as a better-than-nothing stopgap where a more effective technique cannot be applied. But note how it provided a foundation upon which clamp-on technology was able to improve by eliminating the principle hazards. A similar problem may exist at sites fed by a local generator, such as construction sites. Here, an adequate current path may exist between generator ground and equipment grounds, but it may be difficult to distinguish how much of the resistance is being contributed by each element. Even so, a clamp-on may be invaluable for comparative measurements even if they cannot be recorded as absolute. Storage tanks often require grounding. As to testing them, the same consideration applies; if there is an electrical circuit from the utility with a grounding Continued on page 22
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FEATURE • Megger
Continued from page 20
connection to the tank, clamp-on can be used. An isolated storage tank would have to be tested by a conventional method. What amounts to electrical “shorts” are a more devilish problem. These are grounding arrangements where the clampon’s test current can complete a circuit entirely through metal, without ever entering the soil. Intuitively, a “ground” test must involve the “ground”! More elaborate grounding schemes where the electrical system is connected to the electrode at multiple points present a situation where test current can complete a circuit without ever leaving the electrode under test. An example would be a substation, where all metallic elements are bonded together in a Faraday cage. Clamping on anywhere just allows the current to circulate through the “cage” and present a continuity test of the structure. No “earth” is involved. Of course, a nice low reading of a tenth of an ohm or two would be expected, but to an operator never trained on the instrument, this could be taken for a good “ground”!
Knowledge of the structure of the electrode is critical here. Test current must not be able to loop back through the electrical system. It must find a return path through soil. Note, however, that the requirement for a complete circuit means that the clampon is also simultaneously performing a bond test. If there were a poor connection somewhere in the loop, as for instance a corroded neutral-to-ground jumper, this would show up as an uncommonly high reading and act as a flag to the operator to troubleshoot the system. Indeed, a clamp-on can be conveniently used for a quick bond test of low-impedance continuity. Just be sure it is understood what is actually being measured. Since clamp-ons already have a current winding, it is a simple step for manufacturers to add a current-measurement feature. When measuring electrode resistance, the tester responds only to its own generated frequency. By merely moving the selector switch to a current function, the clamp-on
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Electrical Products & Solutions • January 2013
can measure and display current over a broad band of frequencies. The principle use is for operator safety. Without ever touching the rod or conductor, the operator can tell if there is current flow…possibly dangerous…on the grounding system. Secondarily, this function can also help in assessing power quality problems. Clamp-on measurements have an additional possible drawback of being unverifiable. Established methods using a conventional tester can be rigorously verified through the associated mathematics and/or graphics. Clamp-on measurements cannot, making the operator’s knowledge and practice all the more important. The methods employed by conventional testers are rigorously described in standards published by independent specifying organizations; clamp-on is not. So it can be seen that the operator’s skills, knowledge and experience are invaluable tools, as always. Clamp-on can make a job easier and quicker. It is an adjunct to knowledge and training, not a replacement. ❏
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FEATURE • ACR Systems
The Data Logger Buying Decision
By Gordon Smith, AScT, Product Manager, ACR Systems Inc.
There are many terms used to describe methods of gathering information about electricity that are relevant to the job at hand – load, demand, kVA, kW, apparent or real power, etc. With the advent of computer technology, the data can be interpreted in many different ways but today’s economy demands that jobs be accomplished with the least effort to remain competitive. There will always be more technologically advanced devices on the market but do they make the task easier or more complicated? Separating these measuring tools into skill categories helps the buying decision.
SKILL LEVELS Looking at the measurement products in the market place, they can be associated with levels of expertise. Level
Measurement Tool
Novice
Handheld Clamp-on Meter
Intermediate
Self-Contained Data Logger
Expert
3-Phase Power Analyzer
Novice
Expert
Now for experts in the field there is 3-Phase Power Analyzers with no less than 3 current probes and 3 or 4 voltage clips with a display and power supply. They can take considerable time to setup and use depending on how savvy the technician is. This is ok for special applications but for routine work like determining existing loads or load balancing they are over-kill. Considering the higher cost and lack of usability in tight spaces, they are not meant to be left in the field. The Power Analyzer does give a lot of useful information when troubleshooting and is the tool of choice when looking at sinusoidal wave forms. Breaking it down, you get what you pay for but do you really need all the extra features outlined in the promotion material? Not if you want to save money and keep the job simple.
First look at the novice or entry-level approach. The analog current probe style Amp meter gives the electrician a relatively simple tool to check instantaneous load currents. Its needle is naturally dampened by a slow response to fast changing Amperage making it simple to read and record at a glance. Next is the digital version with its many features that mask the fact that it acts differently than its predecessor – it digitizes at a fixed rate and has a jerky response to the eye as the digits update and finally settle on a value. Again, it flips another couple of digits, so which read- REQUIREMENTS ing should be recorded? The next logical step is to log this inThe requirements are related to job function and can be broformation automatically in order to get rid of the indecision. ken down by project phases. Intermediate
For the intermediate level, Data Loggers using split-core current transducers have filled an industry need for portable test tools that give long-term data while being reliable and cost effective. Like its former counterpart the Analog Clamp Meter, a 10-year battery powered data logger does not require battery changes in the field. This is important when recording data because there is no wasted effort caused by dead batteries and the data is always available at the end of the recording session. A passive probe means there is no need to tie into any power source whether in the panel or outside. Less reliable recorders rely on rechargeable batteries while others require a wall adapter to be plugged in. 24
Electrical Products & Solutions • January 2013
Phase 1 - Plan 2 - Build 3 - Commission 4 - Operate
Function Electrician Technician Engineer Data Study Installation Design Troubleshooting Verification Maintenance Performance
Concern Amps-FLA FLA-kVA kVA-kW kW-kWh
Plan
The best example is the NEC requirement to Determine Existing Loads before a project begins. The electrical code says in lieu of a years worth of energy demand data, Amperage recorded for one month at 15min intervals is required and that the peak value be adjusted for seasonal loads. What is actually required? The peak Electric Current and the name plate data Continued on page 26
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FEATURE • ACR Systems for either the heating or cooling system. The standards code is asking that the electrical components be sized for FLA with the appropriate design factor applied and that everything be accounted for in the calculation. It is not asking for real power applied to the load in kW because the system needs to handle the maximum peak current seen by the circuit. This is where the re-
Continued from page 24
quirements and the features get blurred. Given that incoming power is usually the purest sine wave and the electrical code does not stipulate otherwise if you measure True RMS you are actually running the risk of sizing the conductor too large. Given: Average RMS = True RMS for a perfect sine wave.
Most loads being inductive or worst case are switch mode conduct only at the peak of the waveform, the True RMS current reading will be higher than the Average RMS measurement for a given load. There are two schools of thought here, one is to size everything larger based on True RMS driving up material costs or pay more attention to mating more surface area in connections and splices where the failures occur. The world has gone full circle and is are back to requiring the equivalent of the Analog Clamp Meter with the addition of recording readings at a preset interval - either time stamped readings or better yet a printed graph. This is the premise of a Portable Data Logger; it records into its memory for backup later. By loading software onto a laptop or computer in the office, the logger is set to take readings either continuously or stops when it is full. Using Average RMS Split Core CT(s), it is easily attached around the current carrying conductor(s). Build
The design Technicians and Engineers are interested in apparent power in kVA for equipment sizing so again Average RMS is more relevant for the reasons stated above. The real power applied to the load is considered when selecting the equipment to meet Energy conservation efforts – this effective power or Watts is concern for energy audits. Power factor comes into play only when adding capacitor banks and is already provided by most equip. manufacturers by meeting Energy efficient standards. Measuring voltage adds unnecessary cost and setup to recording when considering these facts. During the design phase voltage can be assumed as it will not be known for sure until the project is complete. So if tests are necessary to assure that devices meet specification it is prudent to use the rated voltage from the name plate rather than the voltage applied. With Data Loggers this is accomplished by keying the value into an equation that calculates kVA. Commission
On the practical side, all these instruments can be used for a load balance test however the steps involved require the Electrician to make Continued on page 28 FOR FREE INFO, CIRCLE 43 ON READER SERVICE CARD
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FEATURE • ACR Systems
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[ changes immediately. Using a Clamp-on Meter and moving it between phases after switching load combinations on/off and writing down the readings is a pain especially as a one person job. The Data Logger has the ability of recording all phases simultaneously and view them in real time the same as the Power Analyzer. How much time has actually been saved? For the electrician, probably none as changes need to be made at the distribution panel anyway to correct imbalances. However during the commissioning phase, recording can be an invaluable as systems are tested and brought on line with no electrician available. This is especially true for other trades such as HVAC-R when they are working independently and they are responsible for significant loads such as large fans and cooling.
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The Data Logger has the ability of recording all phases simultaneously and view them in real time the same as the Power Analyzer.
]
Power Analyzers are invaluable for troubleshooting anomalies as their manufacturers point out. However, the trick is getting the bulky instrument inside the distribution panel when it has to left on site. Not to mention, leaving an expensive piece of gear in the field and hoping nobody steals it. Longer term 3phase recording can be accomplished by sub-metering but when tracking down offending loads it helps to have a recording device to move around the plant. Operate
Operation and maintenance depend on gathering similar information previously described for upgrades and troubleshooting. Verification and performance on the other hand look for proof of meeting the project specifications (which are Continued on page 30
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FEATURE • ACR Systems
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designed from the requirements). This is generally a high level ment, then a portable data logger is advantages. The Power Factor task that amalgamates data for reporting purposes. can also be keyed into the software to approximate billing which Verification is done in the field making sure each sub-system a compound equation can integrate into kWh. performs to spec. The easiest way to prove or disprove whether CONCLUSION requirements are met is show a picture – full featured trending Each of the tools outlined The easiest way to prove or software plots dissimilar data have a role to play in the job on a graph showing perforfunctions and project phases. disprove whether requirements mance over hours, days, weeks, Handheld meters are quick and months or even years. An exeasy to use. Power Analyzers are met is show a picture – full ample is plotting ambient temare ultimately useful instrufeatured trending software plots perature against power ment. Portable Data Loggers consumption to account for the are the best of both worlds dissimilar data on a graph showconditions that exist at the time when it comes to gathering data ing performance over hours, the data was captured. from the field - they are relaNow the question arises – tively simple to operate and days, weeks, months or can an Average RMS Data their compact size make them even years. Logger be used to record kW easy to deploy. An interface caor effective power? The anble and software is all that is swer is yes, if consideration is given to where the data is collected, needed to complete the kit when using an estimating computer as the benefits of using a data logger can out weigh any inaccuracy. the viewer and printer. What does this all mean to the contractor? Looking for the simPower from the utility should be pure otherwise penalties are paid that show on the billing. This means PF is close to 1 and voltage plest solution does contribute to the bottom line both from a capiand current waveforms are sinusoidal. If throughout the physical tal cost and manpower stand point and the job gets easier with the plant this holds true, which should be the case with quality equip- right choices. ❏
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Industry NEWS
Architectural Products magazine names Digital Lighting Management best lighting control system Architectural Products magazine awarded WattStopper’s Digital Lighting Management (DLM) self-configuring lighting controls a 2012 Product Innovation Award (PIA). The PIA award program honors innovation in buildings-related products of interest to readers, including architects, specifiers, interior designers and building owners/operators. WattStopper’s PIA ’12 award for DLM was in the Lighting/Electrical category. Winning products, judged by a group of 50 independent industry professionals are featured in the November 2012 issue of the magazine. Competing products were assigned to judges based on their expertise and interest. Judges were asked to assign a numerical grade to each entry and comment on particular aspects of the product they found innovative or intriguing. Summing up comments from its judges, Architectural Products observes, “Controls, be they for lighting or HVAC, are something so many are simply afraid of as if expecting a pop Trigonometry quiz. But to make the kinds of energy impacts we’re all talking about with sustainable buildings, even net-zero energy buildingsthey’re essential. Thus any effort to simplify the process is most welcome, and WattStopper’s intelligent DLM system does just that with self-configuring sensors and personal controls that not only deliver better lighting, but a better bottom line.” Digital Lighting Management is an intelligent suite of distributed lighting controls, including occupancy and daylighting sensors, personal controls and other components, which saves more energy than conventional controls. WattStopper engineered DLM to meet and exceed energy codes out of the box, facilitate sustainable development and provide an unprecedented return on investment for new construction and retrofit projects. The all-digital DLM systemis the first to automatically configure devices for the most energy-efficient operating profile. Plug-in connections reduce installation time by 50% and eliminate the potential for wiring errors. Ladder-free remote configuration via an industry-first wireless IR tool that can store numerous system parameters further speeds startup or adjustment of large projects. Digital Lighting Management systems can operate as stand-alone rooms, for the lowest installed cost, or as part of a centrally controlled system or BAS. System integrators can easily incorporate them into an intelligent building system via an open protocol network bridge. Furthermore, DLM continues to operate from the bottom up, ensuring reliability even in the event of a network fault. ❏ WattStopper (www.wattstopper.com), a Legrand group brand, is a leading manufacturer of energy efficient lighting controls for commercial and residential use. We help customers find convenient ways to save energy, meet green initiatives, and comply with energy codes with our comprehensive range of products, programs, and services. Legrand (www.legrandelectric.com ), located in Limoges, France, is the world specialist in products and systems for electrical installations and information networks, offering solutions for use in residential, commercial and industrial buildings. 32
Electrical Products & Solutions • January 2013
Kaiser Electric Hires Design Engineer Brian Litteken Kaiser Electric recently hired Brian Litteken of St. Peters, MO as a Design Engineer. Litteken is responsible for designing and reviewing engineered documents for design/build projects, designing detailed drawings for field installations and pre-fabrication, and assisting project managers with equipment layout, conduit routing, etc. Prior to Kaiser, Litteken worked for Ascent, LLC for a year as a Project Engineer and as a Project Manager/Estimator for two years at Sachs Electric. He also previously worked for Kaiser Electric for three years as an Assistant Project Manager and a Manager of the Communications Department. Litteken has a B.S. in Electrical Engineering and Computer Engineering from the University of Missouri, Columbia. He has also successfully completed the FE/EIT certification exam. ❏ About Kaiser Electric Kaiser Electric has been providing electrical contracting and engineering services to the St. Louis metro area for more than 60 years. The company focuses primarily on industrial, commercial, healthcare, design/build and communications projects and employs 150 field electricians with a fleet of 50 vehicles. Kaiser Electric is headquartered in Fenton, MO with divisions in Central Missouri and Southern Illinois. For more information about Kaiser Electric, visit http://www.kaiserelectric.com or call 636-305-1515.
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Product FOCUS Acuity Brands Extends Leadership Position with High Lumen LED Downlighting Series from Gotham Architectural Downlighting New Incito series of solid-state luminaires handle a wide range of lighting scenarios with up to 2,000 possible performance combinations. Acuity Brands, Inc. continues to demonstrate its innovation leadership with the introduction of the Incito™ LED open downlight series from Gotham Architectural Lighting. Incito is a new series of solid-state luminaires that combine the performance characteristics of multiple light sources and handle a wide array of lighting scenarios. Incito downlights feature top performance characteristics – lamp life, dimming capability, color, efficacy, and lumen packages – from multiple light sources in a single system, allowing designers to configure luminaires for a variety of ceiling heights from 12- to100-feet. The series also combines long-life LED technology, seamless dimming capabilities and numerous lumen packages, ranging from 2000 to 6500 lumens. “The design team at Gotham has created a revolutionary LED platform combining the best attributes of quartz, halide and metal light sources for up to 2,000 possible performance combinations,” said Douglas Grove, Gotham Value Stream Leader. “The result is a dramatically increased variety of spaces – from retail stores and restaurants to hotel lobbies and auditorium theaters – that can be illuminated with greater precision and more freedom.” Incito downlights deliver the energy efficiency and long life of solid-state technology, which results in both energy and maintenance savings over downlights using traditional light sources. It also provides system-wide control because every device in every zone or network is digitally addressable using nLight® technology from Acuity Brands. Incito downlights also offer ultra-smooth dimming capabilities from 100 percent to less than 1 percent standard. Abundant lumen packages allow Incito downlights to work in many different spaces from atriums to lower corridors. Its diffused lighting, aesthetic appearance and color consistency complement the popular EVO® line of LED downlighting luminaires from Gotham. For more information, visit www.acuitybrands.com
Bridgeport Introduces Mighty-Rite® Split Grounding Bushings Can be installed before or after pulling wire without expensive rework Bridgeport Fittings’ Mighty-Rite® Split Grounding Bushings (SGB) can be installed before pulling wire or after, eliminating expensive rework. This innovative feature from Bridgeport also makes pulling larger conductor wire easier when contractors can install grounding bushings after the pull. The patented SGB Series from Bridgeport features a low profile design, captive screws and a hinged design that adjusts and aligns more easily, even in tight spots. The bushing’s adjustable grounding lug accepts wire easier. Bridgeport’s Mighty-Rite solution includes a 150°C Rated liner and is available in trade sizes from ¾-inch to 4-inches. The SGB products are cULus Listed. Mighty-Rite Split Grounding Bushings are part of Bridgeport’s exclusive and innovative Mighty-B™ line of high-quality, high-performance products that allow contractors to safely and easily install electrical systems while getting the job ‘done fast, done right.’ Bridgeport Fittings is a leading supplier of quality fittings to the industrial, commercial and residential channels of the electrical industry. Nearly three-quarters of Bridgeport’s product volume is manufactured in the U.S. For more information, visit www.bptfittings.com 34
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Product FOCUS Klein Tools® Expands Its Cable Measurement Line With The VDV Distance Meter™ A professional cable length meter at an entry-level price Klein Tools for professionals since 1857, introduces the VDV Distance Meter for pair-conductor cables. This tool measures cable length, locates faults, in addition to simplifying inventory, estimates and billing jobs. With an entry-level price point, The VDV Distance Meter lets tradespeople test and measure cable with confidence and ease. Klein Tools’ VDV Distance Meter (Cat. No. VDV501-089) measures voice, data, video, doorbell, siamese, lamp-wire and NM cables up to 1,500 feet. It has six pre-programmed nominal cable length constants for RG59, RG6 and RG11 coaxial as well as Cat3, Cat5e and Cat6 twisted pair. In addition, the VDV Distance Meter lets the user adjust the capacitance/foot constant based on the cable being tested. This tester also ensures compliance and identifies cable runs outside specification. The fault finder feature determines if a cable run is broken or damaged. Furthermore, the VDV Distance Meter saves time and increases efficiencies by measuring cable remaining in a box or on a reel as well as facilitating estimates and billing jobs correctly. “Our customers want a dependable measuring tool at a cost-effective price,” states product manager, Chris Niklas. “The VDV Distance Meter is the only product that can measure cable length and determine faults at this price point while maintaining quality and reliability. It is a great addition to the Klein VDV Scout™ Pro which tests for cable continuity.” For more information, visit www.kleintools.com
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Product FOCUS Milwaukee® Expands Test & Measurement Line with Milliamp Clamp Meter Milwaukee Tool Corporation continues to expand their Test and Measurement line with the introduction of the Milwaukee® Milliamp Clamp Meter. Over 10X faster than measuring milliamps with a traditional multimeter, the Milliamp Clamp Meter is designed for measuring 4-20 mA signals used in control panels to collect and send data, and can measure 0 to 99 mA to cover a broad range of control signals if needed. Enhanced design features of the tool will allow professional electricians, HVAC technicians, building maintenance specialists and others working with 4-20 mA signals to troubleshoot an entire control panel faster and more easily. “The Milwaukee® Milliamp Clamp Meter is designed to save users both time and money,” said Zach Haas, product manager, Milwaukee Tool. “Large control panels can have dozens of wires that need to be tested to identify a problem. The clamp allows users to measure milliamps without having to break the loop, preventing the shutdown of equipment and saving valuable time.” The tool features a long clamp wire and narrow jaw profile for easy clamping in tight spaces. Additionally the high contrast white on black display is easy to read in all lighting conditions. Built with the durability expected from Milwaukee®, the Milliamp Clamp Meter also has secure, on-board clamp storage and a rugged over-molding to protect the meter if dropped and make it easier to use with greasy or gloved hands. With the introduction of the Milliamp Clamp meter, Milwaukee continues to enhance its offerings in the test and measurement category. Milwaukee remains unwavering in their commitment to the trades, and will continue to offer innovative solutions in safety, performance and productivity. For more information, visit www.milwaukeetool.com
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Platinum Tools® Launches New Test Kit for VDV MapMaster™ 2.0 Length Measurement Voice/Data/ Video Tester Now Shipping, the New T129K1 Test Kit for the Recently Updated VDV MapMaster 2.0 Includes the Tester as Well as all the Accessories Required for Voice, Data, and Video Testing & Mapping in a Rugged Double-Walled, Blow Molded Case Platinum Tools® the leader in solutions for the preparation, installation, hand termination and testing of wire and cable, is proud to announce the new complete test kit for the recently updated VDV MapMaster™ 2.0 voice, data, and video tester is now shipping. With an MSRP of an affordable $199.95, the T129K1 Test Kit includes the VDV MapMaster™ 2.0 as well as all the accessories required for voice, data, and video testing and mapping in a rugged double-walled, blow molded case. “The CEPro Best of 2012 award-winning VDV MapMaster™ 2.0 has become popular with technicians in a very short period of time, and now we’re able to provide them with additional accessories and a durable carrying case, protecting the equipment when out on a call,” explained Lee Sachs, Platinum Tools, Inc. president and general manager. “Made in the USA, the kit includes everything needed in a custom cut out, high density EVA foam to help protect the equipment for years to come.” The VDV MapMaster 2.0 now combines cable length measurement with continuity testing, mapping, and tone generator functions into a single unit. Made in the USA, the VDV MapMaster is capable of identifying and mapping 19 locations at one time. Whether the job is commercial or residential, the versatility and added features of the VDV MapMaster 2.0 makes it an installer’s best friend. For more information, visit www.platinumtools.com
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January 2013 • epsmag.net
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Advertiser INDEX This advertisers index is compiled as a courtesy to our readers. While every effort is made to provide a complete and accurate listing of companies, page numbers and reader service numbers, the publisher is not responsible for errors.
Company ACR SYSTEMS AEMC INSTRUMENTS ALBER CORPORATION ALLEARTH RENEWABLES ARPI OF USA BATTCON 2013 CONFERENCE BRADY WORLDWIDE BYTE BROTHERS CONDUIT REPAIR SYSTEMS E-Z METER GENERATOR INTERLOCK TECHNOLOGIES GENSCO HB BRACKETS HERCULES INDUSTRIES, INC. HIOKI USA ICC IRISS, INC. KRENZ & COMPANY MEGGER
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26 IBC 21 11 36 38 BC 37 4 36 7 40 30 28 15 19 1 39 IFC
43 2 16 11 47 49 3 24 6 48 8 52 46 45 13 15 4 50 1
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Company MINUTEMAN UPS MITSUBISHI ELECTRIC NORTHWEST LIGHTING SYSTEMS CO. PHASE-A-MATIC PHILIPS EMERGENCY LIGHTING PLATINUM TOOLS POWER-ONE SCHNEIDER ELECTRIC SOKKIA STEELMAN INDUSTRIES STRIP-TEC SUMMIT TECHNOLOGY, INC. TENMAT INC. THE HOME DEPOT TOSHIBA INTERNATIONAL CORP. UNDERGROUND DEVICES UTILITY METALS YOKOGAWA CORPORATION
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23 17 25 39 22 29 3 9 5 28 12 27 35 13 31 16 10 33
17 14 18 51 42 20 5 9 7 44 40 19 23 12 21 41 10 22
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