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We have a ships brushless ac 440v 450kw 0.8pf generator which is experiencing issues in auto control, would appreciate any ideas for further fault finding. In hand control can achieve rated output In auto we can deliver 100% rated kw out of set in auto control In auto above 50% rated kva the...

what is reason for minimum conductor size that can be run in parallel (other than economic and labour intensity). I am working to marine/offshore rules that state minimum c.s.a that it is permitted to start running conductors in parallel is >10mm.sq. someone asked me if they could run 2 x...

could someone summarise correct procedure for load bank testing generators (individually) and then operating in parallel. Should procedure be:- Individual generators 1. gradually increase load from 0-100% (kW) with generator set in droop mode and confirm correct droop characteristic 2...

we have old motor going for overhaul and OEM recommended procedure written at time of manufacturer (1978) was to DIP and bake. Would you recommend now to VPI? Also regarding test (it is 440V 300kW motor), is a surge test applicable for this random wound machine?

A specification for some control equipment has a statement "welding within 10m vicinity of control equipment disconnect power otherwise supply filters might be damaged and control system function can be jeopardised." Is this common? it is fairly important equipment and I have not come across...

Are you permitted to use 600/1000V grade cable on a 690V IT system that would run with earth fault for >8hrs? or should you use 1900/3300V cable?

thread237-29369 Does anyone have a copy of the paper by Richard Nailsen that was referenced in this thread?

with reference to attached sketch we have a distribution system that is currently operated with two generator plants that are independent, i.e. the 690V switchboard operates independently of the 480V switchboard. Somebody has come up with the idea of reusing an existing sub-distribution feeder...

I have been passed a battery test report to look at( which covers NiCd and Pb battery banks) Are there any good references or threads that I can look at to help me. Thanks

Does anyone know where I can upload the old GE Redspot fuse video? I think it was commonly referred to as the "Blue Cubicle" video.

Where is the correct position to install a surge arrester. The equipment to be protected is a 6.6kV motor. Currently there are surge arresters installed in the switchboard (vacuum contactor application). Searching the web it suggests that it is more appropriate to install at the motor but if...

thread238-274057. Are there any users of this forum, that don't use the power forum, that maybe able to assist with this thread?

I took these waveform measurements of an open transition autotranformer, 65% tap, motor starter (1700kW rating). The generation system is a ships network with two 2.4MW 440V generators. The two waveforms are the start and the run circuit breakers closing. Run closes 40secs after start and the...

Does anyone have any reference literature relating to the cost of arc flash injuries? (obviously the cost of a human life is difficult to account for, but if there are some supporting documents I would be grateful)

Is it possible that UPS output can be upset by a large transient on the UPS input, e.g. a large induction motor start? It should switch to the batteries and give maintained power. What should you look for in a UPS specification if this is a problem

We have calculated some pretty high incident energy levels on our 440V main switchboards. Looking to mitigate the arc flash hazard by either implementing arc guard equipment (light and current sensing) or alternatively considering fitting transformer differential protection on the MV/LV...

What would be the best way to protect a feeder for earth fault for the following arrangement. A ship (totally isolated, IT insulated neutral) is to supply power to the shore. On shore there will be an isolating transformer (either star or delta primary) and a solidly earthed star secondary for...

We have a 3ph induction motor (350kW, 3ph, 440V, FLC=550A, 60Hz). When the motor is switched off, a contactor closes in the mcc to energise a step down 440/35V transformer which puts 35V across 2 of the windings (U and W phase). I think the concept is to use the motor windings themselves as a...

Is there a reference document that defines Classification of Severity for electrical equipment that is subject to thermographic surveys i.e. 0-10degC above ambient corrective measures required at next maintenance 10-30degC above ambient requires urgent action to be taken 40+ urgent If there...

Hi I'm trying to source some of these relays (see attached). Anyone know any go sources to go to?