Interlock for generator

iwire

Moderator
Staff member
Location
Massachusetts
What's dangerous about using a non-UL interlock kit that is designed and works exactly like the ones manufacturers make for their own panels ?
You are assuming they all work the same and as well.

I don't know that they do and neither does an inspector.

I would rather instead of a blanket policy of not allowing them that the inspectors would inspect it and use commonsense to decide if the aftermarket one is just as good.
 

kwired

Electron manager
Location
NE Nebraska
Most jurisdictions including all State inspectors Iknow of here in Washington will not allow aftermarket UL listed interlocks. Although they are listed by UL as a device that meets the intent of the code they are NOT listed for use in any manufacturers panels. The only devices that are acceptable here are the ones that are supplied specifically by the panel manufacturer and designed and listed for that makers panel. That all being said the 2 aftermarket ones I have seen are nearly exactly like the ones some panel manufactures supply and will work just as well.
Does same inspectors reject "classified" breakers in another manufacturer's panel? It is kind of the same situation.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Some inspectors reject the interlock kits because they are not listed as "transfer equipment" and the rule in 702.5 requires the use of "transfer equipment".

The interlock has the required functions of transfer equipment and assuming it fits well enough on the breakers to prevent both of them from being on at the same time, I don't see a problem.
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
You are assuming they all work the same and as well.
The ones that I've used do but I'm not sure if other brands may not.
I would rather instead of a blanket policy of not allowing them that the inspectors would inspect it and use commonsense to decide if the aftermarket one is just as good.
I agree with that 100%.
 

homwire

Member
Location
MA
Sorry for not able to reply until today. The interlock kit I used was from interlock kit.com. I tied the generator breaker to the adjacent breaker and label the breaker with a warning so to prevent anyone from removing it without realizing it is a back feed breaker. In addition, on the cover of the panel, there is more warning about the breaker before anyone removes the cover.

The town gave me a slip stated "Permit to Perform Work" when I applied for the permit. The last time I contacted the inspector again, he said I can use the system with the interlock. Should I be receiving something stated the interlock is ok to use by the town? Any thought will be very much appreciated.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Sorry for not able to reply until today. The interlock kit I used was from interlock kit.com. I tied the generator breaker to the adjacent breaker and label the breaker with a warning so to prevent anyone from removing it without realizing it is a back feed breaker. In addition, on the cover of the panel, there is more warning about the breaker before anyone removes the cover.

The town gave me a slip stated "Permit to Perform Work" when I applied for the permit. The last time I contacted the inspector again, he said I can use the system with the interlock. Should I be receiving something stated the interlock is ok to use by the town? Any thought will be very much appreciated.
From what I've seen those interlocks are not UL listed for most if not all manufacturer's panels so it's up to the AHJ to decide if they're acceptable.
 

kwired

Electron manager
Location
NE Nebraska
If the inspections department passed your work then it would be nice if they would give you something in writing stating just that.
Can't vouch for the way it works where you are at, but if my work doesn't pass I will be getting a notice in the mail stating what did not pass, the code section violated, a demand for reinspection fees, and a notice that I have fourteen working days to correct it (a call to inspector can usually work things out if more time is needed or if there are other problems).

Permits I file on line are able to be checked on line for status, if I want to know if something has been finalized. I also have the option to pay an extra dollar or two to have an inspection notification sent to me upon passing, otherwise they don't send anything if it passes.
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
I'm sorry to "cross threads" here but you should read through this entire thread http://forums.mikeholt.com/showthread.php?t=158292 . When you get to post # (92) I believe this is what the inspector is referring to. The most important part of this entire thread is recognizing that UL-FTCN exists and if it's enforced in your area you will not be able to use this interlock kit or any other, for that matter.

Now, getting back to the original question, as Infinity mentioned the kits sold by Interlockkit.com work great but they do not come with a UL listing (for the record, they're not UL "listed", they're labeled as a UL "recognized" device, whatever that means). In areas where they may still permit the use of these devices many EI's won't accept them because there's no UL label on the package. Another reason they don't like them is the cable tie used to lock the breaker in place, claiming that they can dry out and snap off (a total crock IMHO). However, I've stopped using them because I kept running into EI's that won't accept them. I've since been using the Siemens and Square D units
with their respective panels because thay come with the UL label on the packaging, which I leave behind for the EI to see.
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
Can't vouch for the way it works where you are at, but if my work doesn't pass I will be getting a notice in the mail stating what did not pass, the code section violated, a demand for reinspection fees, and a notice that I have fourteen working days to correct it (a call to inspector can usually work things out if more time is needed or if there are other problems).

Permits I file on line are able to be checked on line for status, if I want to know if something has been finalized. I also have the option to pay an extra dollar or two to have an inspection notification sent to me upon passing, otherwise they don't send anything if it passes.
Boy, there really are a lot of corn fields between you and the building Dept. !!!:p
 

electricmanscott

Senior Member
Location
Boston, MA
Sorry for not able to reply until today. The interlock kit I used was from interlock kit.com. I tied the generator breaker to the adjacent breaker and label the breaker with a warning so to prevent anyone from removing it without realizing it is a back feed breaker. In addition, on the cover of the panel, there is more warning about the breaker before anyone removes the cover.

The town gave me a slip stated "Permit to Perform Work" when I applied for the permit. The last time I contacted the inspector again, he said I can use the system with the interlock. Should I be receiving something stated the interlock is ok to use by the town? Any thought will be very much appreciated.
In this state it'e very rare to get anything from an inspector in writing. Hell it's rare to even get a decent inspection.
 

kwired

Electron manager
Location
NE Nebraska
Boy, there really are a lot of corn fields between you and the building Dept. !!!:p
Yet things seem to work smoother than in metro areas at least most of the time anyway.:happyyes:

Inspector that looks at most of my work has to drive nearly 100 miles to look at a lot of my work, (he lives near one end of his territory and I live near the opposing end) yet we know each other on a personal level to some extent. Some city electricians may live just blocks away from an inspector and really don't know them at all, and may seldom even have the same person look at much of their work.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Engineer
...for the record, they're not UL "listed", they're labeled as a UL "recognized" device, whatever that means....
UL lists items that are complete and standalone.
UL recognizes items that are not stand alone and must be used with another item (a common example is a plug-in 'ice-cube' relay which can only be used with a base assembly). This is the backwards "UR" you see on some devices.
 

homwire

Member
Location
MA
Thank you for all the advice. Now that I know some inspectors do not like interlock, I may not consider to install another one in the future. It is a shame because interlock give you the option to choose which loads to run especially in the cold weather when you need to switch between different zones so the pipe will not freeze up.
 

kwired

Electron manager
Location
NE Nebraska
Thank you for all the advice. Now that I know some inspectors do not like interlock, I may not consider to install another one in the future. It is a shame because interlock give you the option to choose which loads to run especially in the cold weather when you need to switch between different zones so the pipe will not freeze up.
Any manual transfer switch gives you that option, they are just saying they do not consider that interlock as an acceptable manual transfer switch.
 
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