Self Help Forums

Go Back   Self Help Forums > Repair > Electrical - Existing Home
Register FAQ Members List Calendar Today's Posts

Electrical - Existing Home Electrical Repair / Remodeling Ideas / Problem Solving Solutions

Reply
 
Thread Tools Display Modes
  #1   IP: 68.34.36.21
Old February 10th, 2007, 07:04 PM
thammel thammel is offline
Member
 
Join Date: Sep 2006
Posts: 33
Default subpanel placement above floor height

Hi,

I'm installing an automatic transfer switch box and a subpanel in my basement. Ideally I would like to installthem one above each other. One is 18" high and the other is 24" high. The wall is 92" high and allowing 6" between the two boxes gives 48". Placing them so the top box (subpanel) is 12" from the ceiling gives 60", which places the bottom of the ATS box 32" off the floor. Does this sound like a problem? I could place the boxes side by side but it wastes space in the loacation where I'm placing them.

PLease let me know your thoughts on this one,
Thanks,
Tom
Reply With Quote
  #2   IP: 69.131.230.187
Old February 10th, 2007, 07:30 PM
epojr epojr is offline
Junior Member
 
Join Date: Jan 2007
Posts: 25
Default

I'm not an electrician so I don't know about the code requirement, if any, for the height of breaker panels from the floor. But I have learned by recent experience that it's a lot more difficult and potentially dangerous to work in a high mounted panel from a step ladder than it is standing on the floor at eye level with your work.

It would be even harder and more dangerous if your panel is located where you're in the dark when the main breaker is turned off as mine is. My wife and I spent the better part of the afternoon in the basement yesterday installing a new 240V circiuit in our main panel where she had to hold a flashlight for me to see by and I had to work standing on a ladder. I don't want to put myself in that situation again any time soon.
Reply With Quote
  #3   IP: 24.16.225.236
Old February 10th, 2007, 07:43 PM
suemarkp suemarkp is offline
Super Moderator

 
Join Date: Dec 2003
Location: Kent, WA
Posts: 8,210
Default

There is a height limit for overcurrent devices (I think it is 6.5'). You'll need to access the breaker panel more often than just a switch, so I'd put the breaker panel on top such that its highest breaker was at about 6' high.

If it is easier to feed from above, and you go through the transfer switch first, the switch could be rather high. Does it have any overcurrent devices in it?
__________________
Mark
Kent, WA
Reply With Quote
  #4   IP: 68.34.36.21
Old February 10th, 2007, 07:52 PM
thammel thammel is offline
Member
 
Join Date: Sep 2006
Posts: 33
Default

Thanks for the replies! The top box will be the breaker panel. It will be set at the same height as the main panel, so that the top of it will be at 80" above the floor. The main breaker in it will be very easily accessible. The transfer switch will be the lower box and it's planned to be placed so it's bottom is 32" above the floor and its top would be 56" above the floor.

The transfer switch does not contain any breakers but just the controls and relay to switch from utility power to generator power and vice versa. It's easier to put the subpanel up top because of existing wire lengths in swapping the generator circuits from the main panel to the subpanel.

Thanks,
Tom
Reply With Quote
  #5   IP: 148.78.243.25
Old February 11th, 2007, 09:48 AM
Wgoodrich's Avatar
Wgoodrich Wgoodrich is offline
Super Moderator

 
Join Date: Sep 2002
Posts: 7,451
Default

Just talking about panel and switch placement you have a maximum of 80" above the floor for any switch lever or breaker being branch or main breaker.

Then you have a rule that no other loads unless associated equipment which would fit that trasfer switch. Problem is your transfer switch will stick out much more than the breaker panel will stick out. This is why they are suggesting you place the transfer switch on top and the panel on bottom.

There is a rule that says breakers must be out of reach of small children. That is a very loose rule. If your bottom box has breakers or switches having the lowest at least say knee high to ensure safe from children you will be alright. The concern is that much thicker transfer box is a source of grounding path to earth. That panel above you are working on if it shocks you will be looking for a path to earth. Just guessing your crotch will be leaning against that lower transfer switch making that path to ground through your heart then through your crotch and other items down there to earth completing the electrical path to flow. My be easy the way you are planning it but may hurt a lot at a minimum and may kill you at a maximum of your crotch is leaning against the lower grounded transfer switch when getting shocked through your hand through your heart and out your crotch. Not a pretty picture to me. YOu choice.

Now I see other concerns. YOu are speaking of transfer switch to a sub panel not grouped with your main service rated panel creating to my understanding a secondary power source mid stream of your wiring design. Not sure you are meeting the code. All power sources are main service rated panels. You seem to be creating an isolated subpanel aka generated main service rated panel not grouped with the factory power entering your home. This would be a violation and safety concern. Just thought I would add that to your thoughts.

Good Luck

Wg
Reply With Quote
  #6   IP: 68.34.36.21
Old February 11th, 2007, 06:49 PM
thammel thammel is offline
Member
 
Join Date: Sep 2006
Posts: 33
Default

Hi WG,

Thanks for your comments. I think I've resigned myself to placing both new panels side by side (6" apart ) at about 5 feet off the ground. I'm not sure what your questions were at the end. This is a standard standby generator installation. I'm using an ASCO ATS and that feeds the Square D QO subpanel which distributes the power that comes from either my main Square D QO panel or the generator. The Square D QO subpanel is rated as a main (has 100 amp main breaker) which will receive power from the ATS. The ATS is fed from my main panel (100 amps/240 V) and from the generator (about 35 amps at 240V). Of course, the ATS determines which is fed out to the subpanel.

Yes, I agree with your concerns re the ATS sticking out far and being placed low.

Thanks,
Tom
Reply With Quote
  #7   IP: 148.78.243.25
Old February 12th, 2007, 03:31 PM
Wgoodrich's Avatar
Wgoodrich Wgoodrich is offline
Super Moderator

 
Join Date: Sep 2002
Posts: 7,451
Default

What size if your main service rated panel serving that 100 amp sub panel you are attaching your generator to? If you leave the main in the sub panel on you will be energizing the main service rated panel backwards. May be I am not picturing what you are calling a sub panel but I am picturing a panel that is a slave of a remote panel elsewhere in your home where the power company connects.

Curious

Wg
Reply With Quote
  #8   IP: 24.41.38.92
Old February 12th, 2007, 03:50 PM
Ohm1's Avatar
Ohm1 Ohm1 is offline
First Class Moderator

 
Join Date: Dec 2003
Location: WA
Posts: 4,631
Default

The max to the center of the switch lever, main breaker or branch circuit breaker is 6' 7"
__________________
Learning brings success. While you are waiting, I'm getting better!
Reply With Quote
  #9   IP: 24.16.225.236
Old February 12th, 2007, 04:43 PM
suemarkp suemarkp is offline
Super Moderator

 
Join Date: Dec 2003
Location: Kent, WA
Posts: 8,210
Default

It sounds like he has a 100A feeder from his main panel that goes to a transfer switch. The transfer switch then feeds the (sub)panel.

I know of no requirements that a feeder disconnect at a building (the generator feeder) and the service disconnect at a building (main disconnect) have to be grouped. There are requirements that multiple disconnects within each category must be gruoped, but I don't see anything that NEC 225 feeder or NEC 702 disconnects must be grouped with NEC 230 disconnects. Perhaps that is why NEC 702 requires signs on the main disconnect when you have an optional standby system.
__________________
Mark
Kent, WA
Reply With Quote
  #10   IP: 68.34.36.21
Old February 12th, 2007, 06:49 PM
thammel thammel is offline
Member
 
Join Date: Sep 2006
Posts: 33
Default

Yes, Mark has it right. My main panel is a 200 amp service panel. Then I have a 100 amp 240 breaker in this feeding to the transfer switch. The transfer switch (ATS) also has a feed from the generator. Then the ATS decides which goes to the 100 amp (max) subpanel which then gets fed out to the circuits to be fed by the generator (or utility power)

I think all should be ok.

Thanks!
Tom
Reply With Quote
Reply






Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 05:58 PM.


Powered by vBulletin® Version 3.6.7
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
© 2002 - QuinStreet, Inc.
http://www.selfhelpforums.com