Can anyone confirm what readings I should be obtaining when testing for voltage phase-earth on a system which is ungrounded and has a ground fault. 440v phase-phase in normal operation. Would a voltage of 440v to earth indicate a ground fault or would you expect zero volts in the grounded phase...
Hi,
Wondering if anyone can assist me. We have a 1.8MW Emergency generator that we usually carryout 3 weekly load runs on, normal practice is to auto synch with main generation.
My question is we have a power management system controlling the main generators to a pre set base load 95% of...
Wondering if anyone can help me out, we have a 2.24kW pedestal grinder supplied at 440/60/3 - 0.85p.f - would using a 2.5mm2 SWA cable to supply be adequete with a 10A MCB protecting the cable.
calculated the 3 phase current to be 3.5A - anyone suggest/comment on the cable/MCB used. Are these...
Can anyone describe how to test a brushless generator. Looking to test stator - no issues, PMG stator no issues, main excitor stator no issues. Will test diodes - no issues.
Just need to clarify the exact correct way to test the rotor. Would disconnecting the diodes & dc cables from the diode...
Wondering if anyone can help here.
We have an ABB ACV700 VFD, supplied by a 690vdc bus, 690vac to a step up transformer to 2600vac supplying a downhole ESP motor. Drive currently operating/running - however pump discharging very little....? Hertz = 3.5-4Hz, ref = -25.7 and current 413A. This is...
Hi all,
Can someone please state the correct method to adopt in testing a delta connected 3 phase motors insulation resistance, & how it differs from testing a star connected 3 phase motor. We are having a dispute on the matter & an un-baised opinion would settle the argument.
Many thanks.
EK
Can anyone explain to working of an industrial convection oven/steamer.
What possible causes attribute to a safety thermal switch operating. Product Elamo B10-11, could a defective water inlet solenoid cause the thermal switch to operate due to stagnant heat not being circulated hence heat...
Can anyone outline what is required in terms of controls to conform to the EAWR 1989 Reg 14 - live work on LV system/in the proximity of live conductors.
Your help would be appreciated
Can anyone explain the purpose of a blocking magnet within a 11kV ABB SF6 circuit breaker, what is it's function. Circuit breaker is motor charged with 1x shunt trip, 1x closing coil and a blocking magnet.
Thanks for your help
Hi all,
Looking into feasibility of replacing a dual UPS (Chloride) maintenance bypass switch. Switch configured so that it has both UPS's terminating into it, live at all times via one UPS or the other. It is a F&G UPS, plant will be shutdown on isolation of power to catastrophic level. Is...
Hi,
Previously touched in another thread, can anyone outline the correct procedure/step by step method to adopt in proving a HV 3 phase, 11kV system dead given the system is an unearthed type...? Also can you provide opinions for the above but LV system relative.
I would appreciate your input...
Hi all,
Can you explain the effects of a large imbalance between phases R-Y, R-B = 0.38 milli ohm Y-B = 4 ohm when a generator is ductored, IR/PI good.
Star bar disconnected, IR between phases good. Line to line ductor all 3 phases identical. Only when star bar connected is there an issue...
We have a tertiary transformer feeding a DC 690v bus (part of a multi VFD) dist system, DC link section.
Can someone explain why this type of Tx was used for this application, assume cost related...! and also explain how the secondaries that feed the same bus differ in configuration one being...
Hi all,
Happy New Year......!
Would appreciate your advice.
Can someone please indicate the correct procedure to adopt in proving an unearthed IT electrical systems dead. (Offshore Oil/Gas Platform)
With no theoretical earth I would assume that to test for no volts/a dead system you would...
