facilities management review
When Eskom loadshedding strikes, is your power backup investment fail-safe? A wave of loadshedding is hitting the country again, as you would have no doubt experienced. This has resulted in incidents where service providers such as OR Tambo International Airport, Chris Hani Baragwanath Hospital and many others have been unable to operate at full capacity. At Pragma, we also suffered a generator failure at our head office, at a highly inconvenient time. These events prompted us to take a critical look and think about what should be in place to ensure a reliable backup when the inevitable occurs. After all, even backup plans need maintenance.
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couple of our pragmatic engineers put their heads together and came up with the points below. The bad news is that there is no app for your smartphone that will do the job for you. The good news is that if you apply yourself to the suggested actions, you can have more peace of mind when the next loadshedding hits.
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Before you lift a finger, or grab a meter, it is important to get a good understanding of the real-life situation. In any case where you want to ensure predictable, reliable operation of a device (be it a machine, computer, or even a human) you should examine the following: • What are the critical functions you expect from the device?
• What is the critical component that will affect this function? • How likely is that component of the device to fail? In this case, the ‘device’ under discussion is a standby electrical power generator set, aka ‘genset’. For such a genset, the answers to these questions are quite simple, and illustrated below.
Function
Components
Likelihood of failure
Detect primary AC failure
Voltage sensor; actuated switch
Low
Start the engine
Battery, starter motor, engine ignition, fuel
High
Run engine for 2 hours
Engine, cooling, lubrication, fuel supply
Medium
Generate electrical AC
Alternator, regulator
Low
Switch supply connections
Transfer switch
Low
To ensure good reliability and effective delivery of standby power from your diesel- or petrol-powered genset, here are 10 useful, simple tips to bear in mind when caring for such an asset: 1. Ensure that all fluids in the machine are kept at the correct levels: • Coolant level is between minimum and maximum on level indicator • Oil level is between minimum and maximum on dipstick or sight glass (do NOT overfill) • Fuel level is between 75 and 100 percent of tank capacity. This reduces the possibility of condensation absorption into fuel, as well as the risk of premature depletion
2. It is vital that the batteries, used to start the generator engine, are always fully charged. This is ideally confirmed by measuring the voltage of the disconnected battery to be > 12.6 VDC (for each 12 V unit). Furthermore, battery electrolyte, for maintainable units, should always be at the correct levels in each cell of the battery set. For sealed, maintenance-free (SMF) units, the visual indicator should be (positive) green. 3. Ensure that the AC mains powerfailure-detection system, as well as the automatic transfer switching (ATS) system, is functional and is switched into the AUTO RUN or equivalent mode at all times.
4. For gensets that switch on and transfer power automatically, and especially larger sets (100 KVA and more), it is essential to keep the engine oil and coolant at an elevated temperature, typically above 45 °C. This ensures immediate loading capability of the generator, without having to wait a few minutes for engine warm-up. 5. Do regular visual inspections to ensure that all cooling system air ducts, inlet filters, radiators and extraction fans are clear of dust and debris. Air-filter units should be regularly checked for blockages (check filter air block detectors where used).
African Cleaning Review March/April 2020
