Sparks Electrical News October 2018

MOTOR CONTROL CENTRES AND MOTOR PROTECTION

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MORE TROUBLESHOOTING AND PREVENTIVE MAINTENANCE IN LESS TIME

T he Fluke 789 ProcessMeter is the ultimate troubleshooting tool for electricians and in- strumentation professionals, combining the functionality of a loop calibrator with the power of a digital multimeter. By equipping the 789 with a temperature measurement module and the wire- less data logging capabilities of Fluke Connect™ with ShareLive™ video call (sold separately), process technicians can now do a lot more while carrying a lot less. And with its built-in, selectable 250 ohm HART® resistor, it eliminates the need to carry a separate resistor. Since the launch of the Fluke Connect™ app, Fluke has heard from several customers about how Fluke Connect-enabled tools help get more done

Finding a needle in a haystack With the Fluke Connect dc voltage module, Bohling measured a 0-10 V dc signal to a variable frequen- cy drive (VFD) located in a supply air cabinet. The third party panel was inaccessible so the VFD was the only place to test. “If I had tried to monitor the third-party signal at the VFD with a standard meter, it would have tripped an alarm due to ‘no proof of air flow’ by the air flow switch,” he said. “Using the Fluke Connect dc voltage module I found that the build- ing automation system was not sending the proper ramp signal when duct static pressure dropped.” This same FC module helped him find a chronic problem in a dc power supply that was intermit- tently dropping the 5 V dc it supplied. This caused the chiller to fail and trigger an alarm. He left the dc voltage module on the power supply overnight. “The results showed that the power supply dropped voltage and then restored itself. I replaced the pow- er supply with confidence the next day,” John said. “These meters will be of incredible value as safety concerns rise and more tests need to be conducted outside of the electric panels and in more remote locations.”

in less time. John Bohling, a service technician and member of Pipefitters Local 597 in Chicago, USA, recently shared some troubleshooting and preven- tive maintenance tips he collected. Temperature Module Monitor temperature and electrical at the same time Bohling used the FC Wireless K-Type Temperature module for day-to-day troubleshooting applications. It measures temperature in one location and then wirelessly relays the results to a smart phone (with the Fluke Connect app installed). This comes in handy for checking multiple components of heating and cooling systems simultaneously. For example, at one site a temperature module

was set up to monitor refrigerant line tempera- tures while he worked on the refrigeration compo- nents located elsewhere. He also used the K-type temperature module on split system-style chillers. In one instance, the chiller, which had a micropro- cessor-based control, was located in the basement; the air-cooled condenser was located on the roof. Bohling was able to oversee the fan-cycling controls by measuring the motor amp draw using the 3000 FC current clamp. At the same time, he monitored the liquid line temperature using the temperature module, and observed a specific percentage on the microprocessor in the basement. He viewed the re- sults from all three tools simultaneously, in real time, on his smart phone.

Enquiries: +27 (0)10 595 1821

LOCAL COMPANY SUPPLIES MILL EXPANSION PROJECT G auteng-based JB Switchgear Solutions was recently awarded a contract for the design, manufacture and supply of a range of electrical switchgear equipment to Gold 1 – New Kleinfontein Gold Mining Company’s mill expansion project at its Modder East Operations. JB Switchgear’s scope included a number of 525 V-rated containerised motor control centres, an 11 kV containerised switchboard and extension panel, as well as power and lighting transformers. In this instance, its popular ‘Eagle’ series panel design was used for the 525 V MCCs. It is a robust, user-friendly system that carries IEC 61439- 1/2, SANS 1973-1 and IEC/TR 61641 certification, and over 30 000 tiers have been installed in sites across the globe. Starter sizes ranged between 0.55 kW and 75 kW, whilst VSDs ranged between 45 kW and 200 kW. The project essentially included a new ball mill, a new elution plant, and an extension of the exist- ing Carbon-In-Leach (CIL) plant. The 11 kV Ball Mill Motor is rated at 3.3 mW.

Enquiries: +27 (0)11 027 5804