Registration instructions
Registering is fast and easy for Electrical Answer Man. Click here to register. Once you’ve registered and verified your email, you can log in from any page and start asking questions.
Here are two pages filled with helpful questions and answers:
You can ask questions throughout the site—they all go to the same destination.
For the quickest and most efficient help, have your project nearby when we start chatting. It’s best to have your wiring project underway before our conversation begins. Once I’m logged in, your questions will be answered promptly.
Note: Being in eye sight to your project will clearly help us gather information easier.
89 thoughts on “Electrical Answer Question man”
Comments are closed.
Hi,
If you step up 120vac @ 40amperes with a step up tranformer rated @5000watts to 240vac, will the amperage stay the same?
line or load, are you asking about? The line amperage or the load amperage? Define your wire size for each. What is your load side drawing or are you wanting a full load answer? This is to help prevent you problems and a important safety check.
I have a generator that is rated on the 120vac side @ 41.7 amps and the 240vac side @ 20amps and I was trying to figure out if using a step-up transformer would allow me to get more bang for my buck, no pun intended. I would be using 8awg copper.
Thanks, Still learning.
Unfortunately you can’t connect a transformer up to a small generator like that and be safe. Even if you have the grounding correctly connected at the transformer, the generator system design of the generator connections does matter. The connections and the output of a generator are unique to the system it is supplying power to. Most generators used for this are very large. I am talking megawatts and they are designed just for that system completely from each phase to all the grounding and grounded conductors. Because of the unique connections needed, I would not suggest doing that. if you have access to a E.E. and they can look at all your manuals to the generator and you have a full set of electrical prints to the complete power system it will be feeding, I would only do it this way. Generator connections are more complicated than people think. When you are transferring power, the phases being in sequence AND the connections are unique to each system. It is way too complicated to go into a discussion here. I just would not suggest doing it unless you are building a multimillion dollar project with electrical engineers designing the entire electrical system. Take a look at this book and you will get a slight hint at the complexity. http://books.google.com/books?id=Sf1ppwGI6uYC&pg=PA36&lpg=PA36&dq=connecting+a+transformer+to+a+generator+phase+sequence&source=bl&ots=NreJJBwZB5&sig=azLD5ETawIRRXK0OKR5Eb3Ra_tY&hl=en&sa=X&ei=XsYeUJmkLpOc8QTbyIHIDw&ved=0CE8Q6AEwAQ#v=onepage&q=connecting%20a%20transformer%20to%20a%20generator%20phase%20sequence&f=false
Thank you for your help. Much appreciated!
Regards, Forrest T.
Yes, 60A is more than enough. The air compressor is a 5HP motor with a FLC of 27.5A (22A x 125%). Manuf. states the unit has a 44A LRA. I appreciate your help and thank you for your quick response.
Hi. I would like to use a Siemens Disconnect 3 Phase as a 1 Phase double pole and was not sure which terminals to place the black and white(black) wires into or if it even matters. The disconnect is 60A /240V AC (V-) Max. / 250V DC Max, Type VB II and Type 1 – Indoors.
Additional Inform:
Black, White and Green, #6/2 wire, 2 wires 1 ground, 60A 2-Pole CB will be connected to sub-panel in basement, SO #6/2 same wire color to be connected to air compressor switch and to 60A disconnect.
Is your 60amp disconnect big enough? If so you are good.
Just place your two line wires (incoming power) in the top on first two, left to right, and place your load wires (outgoing power) on bottom two, left to right and your done. Scratch the motor load comment, you are not using three phase so that does not matter.
I am looking at feeding 100Amp RV pedestal that have the 50/30/20 receptacles in them. They will be for 50A rated park model units. How many pedestals can I feed off a 400amp main disconnect.
Is this a disconnect or a service panel with extra spaces? If it is a service panel with extra breaker spaces, how many spaces do you have open? Also, I believe the pedestals you have are only rated for 50amps. The reason you have different configurations is for the different types of camper receptacle styles. How much existing load do you have on this 400amp service?
The main service to the site is 2000Amps. We will be going off the 2000A to 400Amp Service Disconnects then using the TAP rule taping off the 400A to feed 100A disconnects to feed the service pedestals.
Let me know if this is not correct. You have a existing 2000amp service and you are installing several new 400amp disconnects on an outdoor free standing racking system with one tap box per rack going to your 100amp disconnects for each area? I would need to know many other details to help you. I cannot do a load calculation for you, if that is what you need for free. Because of many related code rules I would have to see your layout plans with specs. If you do not have plans or specs, you will have to draw out your plans with details and email them to me. If interested in paying for services, let me know. In other words, no way to do a quick answer as to how many pedestals you can have on each disconnect rack without many needed details.
the zinsco panel was the original panel– a GE panel was added with a meter base– the electrician left the neutral wires in the original panel but spliced the hot wires to the GE panel and installed breakers– instead of running the neutral wires over with the hots they substituted a #6 thwn wire as the sole neutral and tied it back to the neutral bar in the zinsco panel as the connection for the neutral connection– so at this point all the breakers are in the GE panel and no breakers are left in the zinsco panel– its like a junction box as opposed to a subpanel
Ok, I see, it was done illegal. This is called a rat electrician job. If you want to make it legally correct, you will have to make your GE panel be the first panel the feeder wires are connected to from your meter base. And just take your old zensco panel and wires going to it out. There is no other way to correct this situation and it meet code. I still do not know how your grounding and grounded conductors are connected to the GE panel? How are is everything wired from your meter as far as grounding? Is it going to the old zensco panel too? Then to your GE panel? If you have everything running through your old panel, you will have to get it straight by a licensed electrician. It is too much to explain here. I can.t explain how to install a service correctly over the internet.
In a panel changeout–the neutral conductors were left in the old zinsco panel and a #6 neutral was run to the new panel with all the hot conductors– the #6 is suppused to take the place of the other neutrals– don’t know about this sec 300.3b nec contradicts this I think– you have any experiance with this wiring method
Which one is your main panel coming from your meterbase? If the Zensco panel is your main panel, you need to connect the second panel as a sub-panel. The second panel must have 2-hots, 1-neutral and one ground. Your neutral must be isolated from the ground in the sub-panel.
i got it, thanks for replying back so quick
i have a junction box with a black & white from my panel,a black&white from my switch,and a black&white going to my light,they are all #14 THHN,obviously the the greens are spliced and tucked away,how do i complete this splice?
What are you powering and what is the voltage? I assume it is single phase American power?
I have a new home and in my master bedroom my tv goes off when I turn my ceiling fan off? It doesn’t stay off it just turns off then comes right back on? It’s not just limited to the one switch on my fan but have noticed it happening with 2 other switches in my master bathroom? I think the lights and plugs are on the same circuit? Would that cause this to happen? Please help!
Normally in a new home the electrician will switch one or two plugs, maybe more in the master bedroom. The plugs themselves have a break off tab to separate the part that is switched and the normal power. This means ex: top half will be switched and bottom half will be normal power, or vise-verse. it sounds like the electrician forgot to break off the tabs on the outlets that are giving you problems. If you remove the plugs and look on the both sides of each plug, you will be able to see if the tabs are broke off. This means totally separate metal pieces, one metal piece on top half(hot and neutral) and one metal piece on bottom half(hot and neutral). What happening is when you throw the switch it is momentarily cutting off the power and back on again. With the tabs broken off, it should operate correctly.