billpollard
Member
I am a retired master electrician about to install a generator at my home. Does a double throw double pole disconnect meet the present requirements of NEC?
Transfer Switch
- Thread starter billpollard
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bphgravity
Senior Member
- Location
- Florida
Re: Transfer Switch
In regard to what requirements? For use as the transfer switch?
In regard to what requirements? For use as the transfer switch?
- Location
- Massachusetts
Re: Transfer Switch
As long as the generator neutral is not bonded a simple DPDT manual switch will be OK if you are using it to select the power source for a sub panel.
If you plan on using this switch on the line side of the service disconnect IMO this switch would have to be a service rated switch with overcurrent protection and an off position as it would now be the service disconnect.
As long as the generator neutral is not bonded a simple DPDT manual switch will be OK if you are using it to select the power source for a sub panel.
If you plan on using this switch on the line side of the service disconnect IMO this switch would have to be a service rated switch with overcurrent protection and an off position as it would now be the service disconnect.
billpollard
Member
Re: Transfer Switch
I'm using it to isolate the incoming power from the generator power so there isn't any feedback onto the main line. The disconnect I'm using is a Cutler-Hammer DT223URK-NPS Double Throw Safety Switch, 100 Amp 240 Volt Three Wire S/N Non-Fusible, Type 3R, Rainproof. My concern is not having the neutral disconnected. Does this meet current NEC standards? The power company says it's okay, but I want to be certain before I install it. I have been out of the business for a few years.
I'm using it to isolate the incoming power from the generator power so there isn't any feedback onto the main line. The disconnect I'm using is a Cutler-Hammer DT223URK-NPS Double Throw Safety Switch, 100 Amp 240 Volt Three Wire S/N Non-Fusible, Type 3R, Rainproof. My concern is not having the neutral disconnected. Does this meet current NEC standards? The power company says it's okay, but I want to be certain before I install it. I have been out of the business for a few years.
- Location
- Massachusetts
Re: Transfer Switch
The neutral can not be switched if the neutral is not bonded at the generator.
If the neutral is bonded at the generator the neutral must be switched.
I am concerned about your placement of this switch, will there be a service disconnect between this switch and the utility power?
In general no equipment can be on the supply side of the service disconnect. 230.82 lists a few items that are allowed on the supply side of the service disconnect, transfer switches are not one of them.
[ May 24, 2004, 03:23 PM: Message edited by: iwire ]
The neutral can not be switched if the neutral is not bonded at the generator.
If the neutral is bonded at the generator the neutral must be switched.
I am concerned about your placement of this switch, will there be a service disconnect between this switch and the utility power?
In general no equipment can be on the supply side of the service disconnect. 230.82 lists a few items that are allowed on the supply side of the service disconnect, transfer switches are not one of them.
[ May 24, 2004, 03:23 PM: Message edited by: iwire ]
Re: Transfer Switch
Iwire's I am not sure I have your post clear:
After reading your post again I think we said the same thing.
Iwire's I am not sure I have your post clear:
If the neutral terminal is bonded at the generator the bond must be removed if the neutral is not to be switched. A neutral is connected to the neutral terminal on the generator and a EGC from the existing electrical system must be run and connected to the generator frame. If the neutral is switched the bond is left in place and a ground rod installed and bonded to the generator frame.
After reading your post again I think we said the same thing.
- Location
- Massachusetts
Re: Transfer Switch
Sometimes I can not express my self clearly.
Bonded Generator, (SDS) transfer switch must switch the neutral.
No bond at the generator (Non-SDS) do not switch the neutral.
Bob
Sometimes I can not express my self clearly.
Bonded Generator, (SDS) transfer switch must switch the neutral.
No bond at the generator (Non-SDS) do not switch the neutral.
Bob
Ed MacLaren
Senior Member
Re: Transfer Switch
To supplement the excellent advice above, perhaps these sketches may be of some help.
Ed
To supplement the excellent advice above, perhaps these sketches may be of some help.
Ed
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