Recent content by stevemechanical

the downstream panel that i need to relocate is on the 4th floor and it is currently grounded by the feeder's rigid metal conduit. I am trying to determine if it is ok to relocate this panel elsewhere by feeding it with the old feeder cables and rigid metal conduit and connecting new feeder...

I have to relocate an electrical distribution panel. It's electrical feeder only uses the conduit for ground. Can I use a splice box to connect the existing feeder to the new feeder and use the new conduit as the grounding means for the new panel? Would this be an approved grounding method per...

I need help with sizing the electrical feeder from the emergency generator to the automatic transfer switch. It is for a 50KW 208V/3PH, 0.8 pf, natural gas unit. The cut sheet says 173 amps Standby and 139 amps Prime. What amperage do i size it for? Thanks

can anyone help me figure out how to design a grounding system for the IT network of a school?

Where can I learn how to do a short circuit calculation? I need to select the short circuit protection rating for entrance equipment for a single family home 230V/1PH/200 amp service. How do i figure this out? website Links/tutorials would be great. Thank you.

pwrengrds, perfect! just what I was looking for. thank you steve

of course i meant a "good website" besides this one :)

rbulsara, i'm a mechanical engineer. I know basic electrical concepts like most engineers, but i am increasingly interested in learning more. Can you recommend a good web site where I can learn more? thanks again for your post. Steve

thank you rbulsara. can you direct me to any electrical eng. formulas?

How do I determine an impedance/resistance value (please correct me if I'm wrong) for a circuit (any voltage) such that I don't get a short circuit?

do these types of units require a neutral wire as well as 3 hot wires? don't they have devices in them that need 120 volt too?

EEJaime, Thank you very much. But I have one question. Why wouldn't you run a neutral also? Aren't there any components in the unit that use 120 volt?

What is the correct wire callout for a 208V/3PH/60Hz packaged air conditioning unit (cooling only) with the following electrical characteristics: minimum circuit amps = 28.7 amperes overcurrent protection = 45 amperes full load amps = 28 locked rotor amps = 156 Thank you

if i'm specifying a new main distribution panelboard (MDP) for a residence, say 208v/1phase, and i have the available short circuit amps from the utility company, then all i have to do to protect my electrical installation from the short circuit amps is make sure the ampere interrupt capacity...

does anyone know of any concerns with a person working in an electrical closet (9ft x 5ft) for a fews hours a day that has a couple of electrical distribution panelboards and a lighting dimming panel?