What residential 120/240 volt panels will accept a transfer switch

Status
Not open for further replies.
S

silverknight

Member
Which panel manufactures make a 120/240 volt residential panel where the main breaker is in the same row as the branch circuit breakers so that a simple mechanical transfer switch can be attached to it and when switched off will turn on a breaker directly across from it. Then a generator that is wired to that breaker can be started to power limited items in the house.
 
G

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
silverknight said:
Which panel manufactures make a 120/240 volt residential panel where the main breaker is in the same row as the branch circuit breakers so that a simple mechanical transfer switch can be attached to it and when switched off will turn on a breaker directly across from it. Then a generator that is wired to that breaker can be started to power limited items in the house.
Click to expand...
I doubt that you will find that, or else that it will be unacceptable since there would be no way to be sure that one set of breakers would open before the other set closed as well as no way to open both simultaneously. That would depend on the design of the breaker(s).
The standard available interlocks require you to first turn off one breaker, move the interlock, and then turn on the other.
 
augie47

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
I have seen the arrangement on a couple of 100 amp panels that were installed as generator supplied sub-panels. Cutler-hammer has a series of covers that are made for that such as CH8GFM. Many other manufacturers have conversion kits also.
 
Last edited:
iwire

iwire

Moderator
Staff member
Location
Massachusetts
silverknight said:
Which panel manufactures make a 120/240 volt residential panel where the main breaker is in the same row as the branch circuit breakers so that a simple mechanical transfer switch can be attached to it and when switched off will turn on a breaker directly across from it. Then a generator that is wired to that breaker can be started to power limited items in the house.
Click to expand...

There are Interlock kits available that work with panels that have a typical vertical main and a horizontal generator breaker.

Click on thumbnails for larger pics

homepgKit01.jpg

65262d1164846749-generator-breaker-interlock.jpg

I would recommend trying to get one from the panel maker so it is listed properly or you could go with the 'less listed' ;) ones that cost more money.

http://www.interlockkit.com/
 
Last edited:
ceb58

ceb58

Senior Member
Location
Raeford, NC
RLyons said:
I don't understand the need for the use of a main breaker if you are using a mechanical transfer switch?
Click to expand...
Look at Bob's photo's in post 5. This is the type interlock the OP is referring to You must comply with 702.5
702.5 Transfer Equipment. Transfer equipment shall be
suitable for the intended use and designed and installed
so as to prevent the inadvertent interconnection of normal
and alternate sources of supply in any operation of
the transfer equipment. Transfer equipment and electric
power production systems installed to permit operation
in parallel with the normal source shall meet the requirements
of Article 705.
Transfer equipment, located on the load side of branch
circuit protection, shall be permitted to contain supplemental
overcurrent protection having an interrupting rating sufficient
for the available fault current that the generator can
deliver. The supplementary overcurrent protection devices
shall be part of a listed transfer equipment.
Transfer equipment shall be required for all standby systems
subject to the provisions of this article and for which an
electric utility supply is either the normal or standby source.
Click to expand...
 
R

RLyons

Senior Member
Location
Changed for anonymity
ceb58 said:
Look at Bob's photo's in post 5. This is the type interlock the OP is referring to You must comply with 702.5
Click to expand...
I just ask cause I usually use the gentran switches which allow you to manually switch selected circuits between gen and utility power. I'm assuming this is not a select circuit manual transfer switch as I originally thought. :thumbsup:
 
S

suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
ceb58 said:
Look at Bob's photo's in post 5. This is the type interlock the OP is referring to You must comply with 702.5
Click to expand...

He is? It sounded like he wants the type that ties two breakers together at the top of each breaker column. I know SquareD makes one for QO and I think Homeline panels. There must be enough travel in the handle that it guarantees disconnect of both breakers before engaging the other. Not sure you'll find one like this SUitable for use as Service Equipment. Most also have 100A to 125A buses.

I think this is the idea, but they make them for panels with a lot more slots:
Xfer Panel.jpg

I even found this one which claims can be wired for SDS type applications (must be a 3-pole interconnect):
SDS Xfer Switch.jpg
 
Last edited:
iwire

iwire

Moderator
Staff member
Location
Massachusetts
suemarkp said:
He is? It sounded like he wants the type that ties two breakers together at the top of each breaker column.
Click to expand...


My understanding is he was looking to find out which panels accept that arraignment, I was pointing out you did not have to go that route, there are other options.
 
Status
Not open for further replies.
Top