Would tin-plated lugs connected to silver plated busbar cause problems? I need to connect 500MCM copper wires to the bus with crimping lugs (UL Listed 540H). The copper busbars are silver plated.
Your inputs are appreciated.
Thanks for the tip wareagle. The edition of NEC I have is 2002 and 348.60 is about grounding and bonding. So it has all to do with grounding - flexible conduits are not recognized as a ground path. Can I get a yes or no to my previous question then?
Thanks very much Contrivers & wareagle. To summarize your replies and tips, the code does not limit the length of any flexible conduit as long as there is a separate grounding conductor run inside it and the conduit run is properly supported as required by code. Is this correct?
Is there an electrical engineering calculation why the code does not allow more than 1.8m or 6 ft of flexible conduit in installations such as taps for lighting fixtures or motor terminations?
Sett:
The unit in question is running as single unit - not synchronized with the other units. There are 3 units one of which is new where the problem occurs. Synchronizing is used when transferring the load from one unit to another.
jbartos:
I agree with you. Actually, the operators are...
Our client reported that they are experiencing an unpredictable and irregular voltage dip with their power supply. They have their own power plant using diesel engine generators. On a particular single-unit operation, they reported that the dip occurs once a month, after two months and twice a...
alehman:
Thank you very much. I think we have the same point of view. Can I e-mail you directly? I would like to ask you some items I am afraid I cannot post here. Also, I do not have any info as to who to contact directly for the manufacturer of the generator in question. I feel you can...
Yes, there are 3 units (2 old and one new). That is why we need to provide the user a recommendation that in the event that the load (when they are using the new unit), falls below 30-35% (but the supplier insists 50%) of the new unit's capacity, they have to operate one of the old units and and...
rbulsara and alehman:
The load as I have mentioned reaches to more than 80% of the generator capacity - this depends on the demand of course. The minimum load usually occurs at night time - but not always. At daytime, the minimum load is around 50%. The generator was sized to handle the entire...
rbulsara
Thanks so much for the quick reply. Actually, we have a project where we supplied and installed a prime rated generator. What we observed is it slobbers (wet stacking) when the load falls below 40% of its rated output. This was observed by the supplier themselves. Now, the supplier of...
I am looking for some standards and/or publications regarding the recommended minimum load (%) of generators (diesel engine-driven) with respect to their rated output - particularly on prime duty generators. I appreciate the help. Thanks.
Hello. Can anybody help me regarding the mounting height requirement of EXIT lights as per NFPA?
I am currently engaged in an on-going construction of a laboratory building and most of the exit lights are located in corridors with three (3) meters ceiling height measured from the finished floor...
For the attention of jbartos:
Correct me if I'm wrong but do I perceive your Jul. 2 post as: AC can be modelled out of a "string" of lightnings - (just) for the purpose of showing an AC wave?
You personally don't mean to say that lightning itself maybe alternating to the effect that...
Theoretically, AC systems whatever the load maybe, shall have a power factor due to the line and load impedance that is a function of the frequency. That is why VA (volt-amperes) was introduced. The watts is for DC systems.
However, for minimal loading and in the absence of any motor loads, as...
Tonymag,
Try this:
http://www.mikeholt.com/studies/harmonic.htm
Also, this is a very practical and interesting one:
http://www.haworth.com/pdfs/e2636.pdf
I'm with jbartos here. I also have the book "Standard Handbook for Electrical Engineers" 13th Edition by Donald G. Fink and H. Wayne Beaty. I went to these pages and the illustrations shows clearly the charges.
It is discussed here (in the handbook) that lightning stroke is...
I think we have gone too far here.
Thanks to all of you for the TIPS. We have different point of views obviously. What I was hoping to get from these posts is a common thinking of what was initially asked: whether the motors downstream of a second transformer may be considered for the...
To rhatcher and jbartos, a big THANKS.
For rhatcher:
I would not like to consume much of your time but here goes:
"- the conductor size and # of parallel conductors for the 480V feeder to the transformer"
5 sets of 3-250mm sq. THW in cable galv. steel cable ladder
"- same...
