The Electrical Contractor Network

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

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!


2017 NEC and Related
2017 NEC
Now Available!

Recent Posts
Parking lot pole light swap....
by ghost307
51 minutes 32 seconds ago
International Wire Colour Codes
by Tjia1981
Today at 12:08 PM
Son of Sparky
by HotLine1
10/20/16 07:43 PM
Speaking of Plugmold ...
by gfretwell
10/17/16 02:37 PM
Broken battery charger? Check for cobwebs!
by gfretwell
10/17/16 02:30 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 12
HotLine1 7
ghost307 6
renosteinke 6
Potseal 4
Who's Online
0 registered (), 259 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#13060 - 08/23/02 02:47 PM transfer switch
derater Offline

Registered: 03/30/02
Posts: 182
Doing generator/panel transfer switch tomorrow, 200a res.,Never did one and my partner(who has) can't be there.Any tips?

Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#13061 - 08/23/02 03:24 PM Re: transfer switch
George Corron Offline

Registered: 05/16/01
Posts: 728
Loc: Lorton, Va USA
They're fairly self explanatory, read the instructions (sorry, I know that's NOT the electrical way ) it's pretty much Normal line in, Line out, Emergency line in. You didn't say manual or automatic, auto means you have a start signal to genset, transfer signal from source to contact (which is sometimes pre-wired). You'll do fine, take a deep breath, another drink of coffee, and dig in.

#13062 - 08/23/02 03:51 PM Re: transfer switch
go-go Offline

Registered: 08/08/02
Posts: 42
Loc: Fla.

#13063 - 08/24/02 04:57 AM Re: transfer switch
electric-ed Offline

Registered: 07/08/02
Posts: 184
Loc: Canada
Make sure you have the correct transfer switch for the type of generator being installed.

If the generator neutral is bonded to the frame by the manufacturer, a transfer switch that breaks the neutral (three pole) is required.

Here is a basic diagram for a typical generator with a bonded neutral.

However, if the generator neutral is not bonded to the frame, a transfer switch with a solid neutral buss (two pole) is should be used.

Here is the basic diagram for a typical generator with a floating (not bonded) neutral.

Hope this helps,


#13064 - 08/24/02 05:20 AM Re: transfer switch
scjohn Offline

Registered: 07/04/02
Posts: 76
Loc: charleston, SC, USA
ElectricEd, is the use of the 3 pole switch to protect the generator, or the lineman? I have installed a couple of these and have always thought that breaking the neutral would seem the safest for the lineman. The people at Ronk swear that you only need a single pole switch in a single pole application, not to mention the extreme difference in price. What do you think?
Thanx, John

#13065 - 08/24/02 05:36 AM Re: transfer switch
electric-ed Offline

Registered: 07/08/02
Posts: 184
Loc: Canada
No, John. The neutral must be switched to prevent the equipment bonding conductor (EGC) from being in parallel with the neutral in installations where the generator neutral is bonded to the frame.
This would permit the neutral (unbalanced) current to flow on the EGCs which is a NEC violation.

Note also that in these cases, where the neutral is switched, the generator neutral is required to be earth grounded.


[This message has been edited by electric-ed (edited 08-24-2002).]

#13066 - 08/25/02 05:42 AM Re: transfer switch
Scott35 Offline

Broom Pusher and

Registered: 10/19/00
Posts: 2724
Loc: Anaheim, CA. USA

Again, great work on the Schematics!!!

Scott S.E.T.
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!


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