ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals

Topic Options
Rate This Topic
#199652 - 03/03/11 07:17 PM Generator backup for home
pooL8 Offline
Member
Registered: 02/18/11
Posts: 56
Loc: BC Canada
5000W Generator backup for a house, 20A 120/240 output
Tranfer Switch is 2 30A breakers
I'm using #10 (20A X 1.25) ? for all feeders
Should breaker from main panel be 30A, or 20A?

I used 30A in the past (cause I was told to), but with a 20A output from the Generator, I'm second guessing. Maybe I'm missing a rule or something.

What do yalls think?
Top
Tools for Electricians:
#199653 - 03/03/11 07:29 PM Re: Generator backup for home [Re: pooL8]
Trumpy Offline


Member
Registered: 07/05/02
Posts: 8211
Loc: SI,New Zealand
You're using circuit-breakers as a transfer switch, is that legal?
I was under the impression that a transfer switch had to be a manual change-over switch that broke the incoming mains hot and neutral conductors.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin
Top
#199663 - 03/03/11 10:27 PM Re: Generator backup for home [Re: pooL8]
jackolsen Offline
Member
Registered: 02/11/08
Posts: 21
Loc: british columbia canada
Pool8 have you checked the BC Safety Authority web site.here on Vancouver island the safety authority put on a tech talk
about back up power systems and there is a directive on this subject,you should be able to download a copy of it
Top
#199664 - 03/03/11 10:44 PM Re: Generator backup for home [Re: jackolsen]
pooL8 Offline
Member
Registered: 02/18/11
Posts: 56
Loc: BC Canada
Sweet thanks
Top
#199665 - 03/03/11 11:02 PM Re: Generator backup for home [Re: Trumpy]
pooL8 Offline
Member
Registered: 02/18/11
Posts: 56
Loc: BC Canada
The Breakers are side by side, with an interlock clip.

The TS that I am speaking of doesn't have an extra pole on the breakers for the neutrals. I was wondering about that too.

I just read that if Generator's neutral is bonded to it's own ground, then the neutrals need to be switched, but if it isn't then neutrals tie together. (I'm not entirely sure, but that's what I read).
Top
#199673 - 03/04/11 06:22 AM Re: Generator backup for home [Re: pooL8]
wire_twister Offline
Member
Registered: 07/25/07
Posts: 265
Loc: Georgia USA
Pool,
That is correct, you do not have to break the neutral, just be sure it is isolated from ground in the transfer switch. Now go and get yourself a real transfer switch, before somebody takes the interlock off your breakers and does some damage, or worse. You can get a Cutler Hammer 200 amp switch from Harbor Freight tools for around 200 here, i think its worth that much for peace of mind, not to mention liability.
_________________________
Jimmy

Life is tough, Life is tougher when you are stupid
Top
#199688 - 03/04/11 03:56 PM Re: Generator backup for home [Re: wire_twister]
pooL8 Offline
Member
Registered: 02/18/11
Posts: 56
Loc: BC Canada
woah, that's a good price.
The one I'm eye balling is a FP from Canadian Tire. It's $250.

I haven't checked the wholesaler yet. They carry SqD and Seimens stuff.

Cool ya, thanks, it makes sense to treat the Generator like a service, or a sub-panel (with respect to neutral), depending on it's grounding.

I would like a section in the codebook that would clarify Generators.... even though all the other general rules do smile Apparently.

I asked an inspector my question about the breaker from the main panel. He said it's just like a disconnect, so 30A is fine. The branch circuit breakers will do their own job.

Now I get it all. Thanks guys... I feel taller or something.
Top
#199689 - 03/04/11 03:59 PM Re: Generator backup for home [Re: Trumpy]
pooL8 Offline
Member
Registered: 02/18/11
Posts: 56
Loc: BC Canada
By the way Trumpy, I probably should have mentioned that it is a portable Generator, with no ground. whistle
Top

Member Spotlight
Member Since: 11/17/00
Posts: 2232
New in the Gallery:
SE cable question
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box


Who's Online
0 registered (), 42 Guests and 11 Spiders online.
Key: Admin, Global Mod, Mod
 
New in the Gallery:
SE cable question
 
Top Posters (30 Days)
Admin 47
HotLine1 43
gfretwell 19
Ruben Rocha 12
Trumpy 9
 
Newest Members
Freecrowder, clee512, Jdscott2005, FAIZAN, Regitest2

ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals