Interlock for generator

Status
Not open for further replies.
H

homwire

Member
Location
MA
I pulled a permit for recently installed portable generator for my home with an interlock. I placed an 30A double-pole breaker to backfeed from generator to the panel. The interlock was screwed to the cover of the panel to prevent turning on the main breaker while generator is running. When the inspector came to inspect the work, he wanted me to put the circuits in a subpanel for the generator because the 30a generator is not sufficient to power the whole panel. I explained to him I am not intended to power the whole house and will only power what I need for that time.

Does anybody know if this is a code violation? The interlock is UL listed. If I separate out the circuits in sub panel that means I have to use transfer switch. Thanks for any advice you can provide.
 
ceb58

ceb58

Senior Member
Location
Raeford, NC
702.4 Capacity and Rating.
(B) System Capacity.

The calculations of load on the
standby source shall be made in accordance with Article
220 or by another approved method.
(1) Manual Transfer Equipment.

Where manual transfer
equipment is used, an optional standby system shall have
adequate capacity and rating for the supply of all equipment
intended to be operated at one time. The user of the
optional standby system shall be permitted to select the
load connected to the system.
Click to expand...

Agree with Bob, inspector is mistaken
 
infinity

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
iwire said:
You are using manual transfer means, the inspector is wrong.

See 702.5 or close to that.
Click to expand...

I agree too. The major advantage of this type of installation is that the end user can choose which circuits he wants to use under generator power. A separate sub-panel wouldn't allow the same amount of flexibility.
 
T

templdl

Senior Member
Location
Wisconsin
homwire said:
I pulled a permit for recently installed portable generator for my home with an interlock. I placed an 30A double-pole breaker to backfeed from generator to the panel. The interlock was screwed to the cover of the panel to prevent turning on the main breaker while generator is running. When the inspector came to inspect the work, he wanted me to put the circuits in a subpanel for the generator because the 30a generator is not sufficient to power the whole panel. I explained to him I am not intended to power the whole house and will only power what I need for that time.

Does anybody know if this is a code violation? The interlock is UL listed. If I separate out the circuits in sub panel that means I have to use transfer switch. Thanks for any advice you can provide.
Click to expand...
I agree with the other guys But the 2P breaker you are back feeding should have a lockdown clamp or screw such that it would have to be removed first before the breaker could be removed. Such a device is used when a 2p breaker is used as a main where such a clamp is required. Even though I believe such a hold down clamp should be used it doesn't,appear as though that was the reason for to inspector's concern.
 
ceb58

ceb58

Senior Member
Location
Raeford, NC
templdl said:
I agree with the other guys But the 2P breaker you are back feeding should have a lockdown clamp or screw such that it would have to be removed first before the breaker could be removed. Such a device is used when a 2p breaker is used as a main where such a clamp is required. Even though I believe such a hold down clamp should be used it doesn't,appear as though that was the reason for to inspector's concern.
Click to expand...

I don't think you can come up with a code section covering what you describe. His 2p 30 is not the main. But this is getting off track of the OP. The main point is the inspector is wrong in his ruling.
 
T

templdl

Senior Member
Location
Wisconsin
ceb58 said:
I don't think you can come up with a code section covering what you describe. His 2p 30 is not the main. But this is getting off track of the OP. The main point is the inspector is wrong in his ruling.
Click to expand...
Then you may not be aware that a breanch mounted main must be held in place with a hold down kit.
So you place the utility supplied main in off position does not the 30a generator supplied breaker now become the main breaker? If not what is it?
When a breaker is reverse feed such as a branch mounted main breaker it must be held in place with a hold down kit to prevent it from being removed?
As I stated that would be the only thing that I would point out the the inspector may have overlooked but otherwise I believe the installation is just fine in my opinion.
 
Ravenvalor

Ravenvalor

Senior Member
Location
Piedmont region of NC
templdl said:
Then you may not be aware that a breanch mounted main must be held in place with a hold down kit.
So you place the utility supplied main in off position does not the 30a generator supplied breaker now become the main breaker? If not what is it?
When a breaker is reverse feed such as a branch mounted main breaker it must be held in place with a hold down kit to prevent it from being removed?
As I stated that would be the only thing that I would point out the the inspector may have overlooked but otherwise I believe the installation is just fine in my opinion.
Click to expand...

I use an Interlock Kit out of Richmond, Va. and they solve the new main breaker secure problem with a cable tie and a do not remove sticker. the cable tie is about 12 inches long and very thin. It wraps around the new main breaker at positions #2 and 4 and also wraps around the adjoining breaker at positions #1 and 3. After both breakers are secured with a single cable tie a 'do not remove' sticker is placed on the remaining cable tie sticking out. This installation has never been turned down by an inspector.
 
mjf

mjf

Senior Member
Location
The incredible, yet very expensive, Hudson Valley,
Ravenvalor said:
I use an Interlock Kit out of Richmond, Va. and they solve the new main breaker secure problem with a cable tie and a do not remove sticker. the cable tie is about 12 inches long and very thin. It wraps around the new main breaker at positions #2 and 4 and also wraps around the adjoining breaker at positions #1 and 3. After both breakers are secured with a single cable tie a 'do not remove' sticker is placed on the remaining cable tie sticking out. This installation has never been turned down by an inspector.
Click to expand...

I apologize in advance and I may be way off, but to me, that just sounds insane.:)
 
T

templdl

Senior Member
Location
Wisconsin
Ravenvalor said:
I use an Interlock Kit out of Richmond, Va. and they solve the new main breaker secure problem with a cable tie and a do not remove sticker. the cable tie is about 12 inches long and very thin. It wraps around the new main breaker at positions #2 and 4 and also wraps around the adjoining breaker at positions #1 and 3. After both breakers are secured with a single cable tie a 'do not remove' sticker is placed on the remaining cable tie sticking out. This installation has never been turned down by an inspector.
Click to expand...

Personally this is a Rube Goldberg arrangement that I would not condone. But if your AHJ approved it he's the one that rules.
 
D

Daja7

Senior Member
Have done tons of these just as homwire described. Never been turned done once.
The richmond units were one of the first to come up with a non manufacture specific interlock but there are quite a few now at less than half the cost. Some are not uL though so you need to check.
 
F

finster1

Member
Location
New Jersey
interlock kit

interlock kit

I agree that the inspector was mistaken, with that said my local inspector ,God rest his sole, also wasn't happy with any interlock installations. He was especially unhappy with any interlock kit that didn't have a holdown screw or plate for the interlock breaker, anyway , while some do have it , some don't and they still were UL listed, which make me believe they were ok to install.:?
 
infinity

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
finster1 said:
I agree that the inspector was mistaken, with that said my local inspector ,God rest his sole, also wasn't happy with any interlock installations. He was especially unhappy with any interlock kit that didn't have a holdown screw or plate for the interlock breaker, anyway , while some do have it , some don't and they still were UL listed, which make me believe they were ok to install.:?
Click to expand...

Pete was a nice guy.
 
T

templdl

Senior Member
Location
Wisconsin
mjf said:
Like I said, maybe I'm way off, but the interlock kits I've installed have come from the panel manufacturer with a clip that bolts the "interlocked" breaker in place.

I just can't believe that a cable tie would be acceptable as a hold down kit.
Click to expand...
That's exactly the point that I was trying to make, a hold down kit so the breaker can not be removed.
 
T

templdl

Senior Member
Location
Wisconsin
mjf said:
Like I said, maybe I'm way off, but the interlock kits I've installed have come from the panel manufacturer with a clip that bolts the "interlocked" breaker in place.

I just can't believe that a cable tie would be acceptable as a hold down kit.
Click to expand...
That's exactly the point that I was trying to make, a hold down kit so the breaker can not be removed.
 
Status
Not open for further replies.
Top