Came across an existing job where multiple 277VAC Fan-Powered VAVs were connected to a single 3-pole 460VAC (3 phase) Breaker, one VAV to each power phase, rather than using three separate 1-pole Breakers, one for each VAV. Does the NEC permit this anywhere? I know it works, but am concerned...

So I'm doing a side job and the coustmer had asked me to replace old rusty panels n breakers for new shiney ones!! So here is my main question. With a 240v corner grounded delta (b phase) so I need a special panel and breakers specifically for grounded deltas .. or will the normal 240v 3 phase...

After having SCE fix a fault in one of our buildings that has a 3 Phase. Apparently their line in was not grounded at the pole. So now that is fixed I have the following questions. There are three wires coming in from the Meter Box to the Safety Switch. 2 are 240V and the 3rd is 0 volts. Im...

Could someone please confirm my understanding of 3 phase generators power output. I'm in Australia so all calculations are in 240v A 30kVA generator in total can provide a theoretical maximum of 30,000/240 = 125A which would be 41.6A per phase? Using a power factor or 0.8 we get a total of...

I am trying to figure out if powering 240v single phase loads will work with a 240v 3phase corner grounded delta system. The system is a 240v 3phase corner grounded delta system with "B" phase intensionally grounded. I have multiple 240v single phase loads and (1) 240v 3 phase load. I know...

Gentlemen, I’m hoping you might be able to help me with a question regarding a 3 phase PDUs and its proper receptacle in a data center environment in Japan. The PDU we were given to work with has a L15-30 plug. Our power source is 3 phases of 120V and a grounded neutral. Ultimately, I want...

I'm a newbie and need help with a new 300W 3Phase 12v wind turbine. I also have an ALEKO SWC503 wind/solar hybrid controller. Turbine has 3 unmarked wires. Controller has 3 inputs for these wires marked A, B, C. Does it matter what wire goes where ? Instructions are sparse, ALEKO won't...

Long-time listener, first-time caller. Please be gentle I have a 200 amp, 240 volt, 3 phase auxiliary panel with 3 #3/0 copper ungrounded (hot) conductors and a #4 copper grounding (ground) wire to a non-insulated ground bar bonded to the panel. I would like to add some 120-volt circuits to...

I have an outbuilding that was formerly used in an industrial application, monitoring seismic equipment. It was completely functional and wired with it's own main shutoff switch, a 600v -->120/208 3 phase transformer and 200 Amp main panel (100 Amp 3 pole main breaker is already installed). When...

3 phase 4 wire 120/208 system. Phase A pulling 50 amps, phase B pulling 50 amps, phase C pulling 0 amps. Is the neutral carrying a load? Or is does the system balance and leave no load on the neutral. OR would phase C need to pull 50 amps as well to fully balance the system. Possibly the same...

Hello, wise ones of electrical ways. I am primarily an industrial/commercial flooring contractor, however we do some residents, and If I have to rent another 35 kva tow behind I may lose my mind. We mainly do Polished concrete and Resinous Coatings, we use a lot of 480v 3phase machinery. For...

What is the purpose of a corner grounded delta configuration? It seems pointless. I was checking out a friend's new storefront that used to house a lumberyard. His son, who he said is an electrician, had setup a subpanel feeding mostly 120v receps, etc. It wasnt until he ran everything that he...

Hello all, I am an electronics engineer, and i have been tasked with bringing a mobile lab up to code for use in the US. While i have a decent handle on most things related to 120v wiring, and of course most things dealing with lower voltages used by electronics, but anything above that and i...

hey all im going to complete my third and fourth year of school this coming year and just wondered if any of you had any websites a guy should check out to brush up before im back in class. cheers,

I am calculating loads for three-phase motors using NEC 430.250. Can anyone tell me if the amps listed in this table are per phase or the total amps drawn by the motor?

My factory will install 75kW 3 Phase Motor (415V) and by using 3C x 35mm2 Armoured Cable. Based on IEC standard, is that the cable enough to withstand the maximum current produce from 75kW motor? Please attached the IEC data if available. Thanks.:)

I'm trying to set up 3 electric heaters in a system plugged into 240V/3phase arranged in a delta. Each heater draws 30A. A diagram of what I want to build can be seen at: https://drive.google.com/file/d/0B1ph7lVxtvhaTV93NXhiRldINlk/view?usp=sharing Will the amp draw on each leg be 60A? I think...

Our existing equipment in factory used the following spec of 3 phase motor. 5.5kW 415/S 1430/63 RPM Now the above "Star" motor was damaged, can we change it to the following spec of 3 phase motor? 5.5kW 415/D 1400/63 RPM Thanks.:):)

By now, I have 3 Phase motor (2.2KW) connected to 3 × 1.5 mm2 Cable. Then I want to replace it with the new motor which is 3KW. Is that 1.5 mm2 cable able to support the 3KW motor? I would like to know how to calculate the maximum allowable Ampere/KW flowing through the cable 3 × 1.5 mm2. Any...

I do not do much work with 3phase 480v, besides wiring equipment to it; I am wondering if this is possible for the service we have it. My boss is looking at installing a 2500amp 120v service for a prototype project for a new design. I can't go into detail because he does not want it to leak...