5 minute read
Project updates
Planned maintenance ensures reliable electrical supply for Acute NHS hospital
WHEN AN ACUTE NHS HOSPITAL IN the Greater Manchester area recently needed to carry out planned ‘intrusive’ maintenance of its main LV switchgear, it called upon Quartzelec to carry out the task over two planned evening shifts.
The building that required the maintenance is dual supplied via two ABB 1250 KVA dry resin transformers that supply two LV panels. Work was carried out over two planned evening shifts, allowing one panel per evening to be fully isolated, with all affected circuits being re-supplied via the other panel.
The LV switchgear servicing, including the interrogation of all air circuit breakers, was achieved following a detailed switching program with assistance from the electrical site AP.
Detailed recordings of the protective devices, ratings and settings were included, and a full report summary was issued upon completion. This included an introduction, results section, and summary of the overall condition of the switchgear. Also included as part of the works was thermographic imaging, which was captured before isolating the supplies. All connections and torque settings were checked and inspected, and each cubicle was thoroughly cleaned. The client now has peace of mind knowing that its LV infrastructure is in good condition and remains fully compliant.
“It’s not unusual to be called in by NHS Trusts at short notice to investigate and resolve electrical issues,” said Andy Taylor, Supervisor for Quartzelec’s Building Services Maintenance team who coordinated the project. “We endeavour to address issues before they cause serious risk to the hospital and regularly go that extra mile for our customers to ensure they remain operating at optimum performance and within appropriate safety parameters.”
Quartzelec maintains a dedicated healthcare support team that can respond to critical issues, and all engineers are HTM 06-02 competent, plus collectively hold an array of safety and process compliance certificates needed to operate in specialist healthcare environments.
www.quartzelec.com
Dry transformers enable production capacity expansion
ELECTROLUX DO BRASIL S.A IS planning to expand its production capacity. For this to happen safely and effectively, the organisation has purchased two 34.5/11.9kV with 15MVA dry transformers from WEG to supply loads connected to more than ten transformers with a voltage class of 11.9kV, which are installed in the plant. One reason for specifying these transformers was their IP54 rating which makes them suitable for installation in unprotected environments, helping to ensure low installation costs and greater ease of maintenance.
Additional benefits of the transformers, which encouraged the organisation to specify the WEG products, were that they help ensure manufacturing process reliability and benefit from energy cost savings as well as power distribution consistency to avoid voltage peaks caused by the 11.9kV local network power supply.
www.weg.net
Condition monitoring pinpoints the exact cause of gearbox vibration
CONDITION-BASED MONITORING IS a proactive maintenance health check for all types of electromechanical equipment and is crucial for identifying underlying system performance issues without stopping production.
Avonmouth Engineering Services (AES) provided this service to an aerospace company, Leonardo, to help investigate a loud noise generated by a lathe gearbox.
The lathe is a critical item in the plant as it is the first step in the gear machining process. The cost to purchase a new machine would have exceeded £100,000 and would also have led to a loss of production caused by downtime while a new lathe was installed.
AES carried out a detailed vibration analysis on the equipment. This is a nonintrusive method that can be used to detect obscure faults such as unbalance, resonance, misalignment or bearing failure. Combining the results with the technical drawings – which outlined the number, location and specification of the gears and bearings in the gearbox – AES was able to pinpoint that the exact cause of the excessive vibration came from a single bearing. Leonardo carried out the bearing change and have confirmed that the machine is now running without issue.
www.avonmouth-es.co.uk
Speedily adapted high-voltage extruder motor
WHEN LARGE MOTORS OPERATING AT HIGH OUTPUT fail, there can be long lead times for a replacement manufactured from scratch. Customised configuration of a suitable standard motor can offer an economical alternative.
This was the case for a petrochemical plant operator which urgently needed to replace a failed extruder motor featuring 6000kW rated power, 10kV nominal voltage, requiring >57kNm nominal torque. Originally, the extruder was driven by a squirrel-cage machine. However, a motor with similar design parameters was not readily available on the market.
Fortunately, Berlin-based Menzel Elektromotoren was able to provide a suitable three-phase slip ring motor. Its design also offered advantages for the application – driving an extruder – as it provides the required full torque from standstill.
Menzel was able to procure a starter for the slip ring motor as well as implement all necessary modifications in-house. Within two weeks, the customer was able to restart the extruder system.
The modular MEBSSL motor series is designed to enable flexible configuration for various applications and conditions. One of the most time-consuming jobs was fitting a bushing in the customer's coupling hub, machining it from a diameter of 280mm to 240mm. In addition, Menzel manufactured adapter plates to adjust the shaft height from 800mm to the failed motor center height of 900mm. The replacement motor is designed with protection class IP55 and cooling type IC 611 with an air-to-air heat exchanger.
www.menzel-motors.com
QUICK PUMP REPAIR HELPS KEEP ROMANCE ALIVE
WEBB-ELEC QUICKLY JUMPED INTO action after it received a call from the manager of a hotel saying that they had no incoming water supply due to a failed pump, at what was an incredibly busy time – the hotel was hosting three wedding receptions during the week, which would have to be cancelled if the water supply could not be reinstated.
Webb-Elec's site team attended the premises within the hour. They were able to isolate, disconnect and remove the faulty pump and took it to the workshop for inspection. The pump was found to be in very poor condition but was also obsolete. A replacement, which would have been the quickest option, was not possible without extensive pipework alterations.
The site team informed the customer of the situation, who instructed them to carry out a repair to the pump immediately.
The repair included a replacement motor, machining and sleeving of the pump shaft and mechanical seal housing due to wear. A replacement mechanical seal was fitted and the impeller cleaned and dynamically balanced. The pump was then reassembled and tested on an in-house pump test rig.
The team returned to the hotel early the following morning and re-installed the pump. They then conducted a full pump test in front of the manager who signed the job off, and happily, all the wedding receptions were able to take place.
