First generator Interlock Kit questions.

[GerryB]

I just installed my first interlock for generator back-up after hearing a lot about them, all good. I had a few concerns though. On the good side I found a site, National Ram Electronics, that has a whole line dirt cheap. I paid $39.00 no tax or shipping for the one I needed and they were all about the same. The Interlock Kit site wanted $150.00 This one was a half inch thick piece of plastic with a thru bolt that allowed it to pivot. My concerns were the power inlet box I installed is the one with the twist lock prongs exposed underneath, so if someone removed the panel cover and turned everything on and maybe didn't put the cover back or removed the interlock bar you would have exposed live wires. The kit comes with postage stamp size stickers warning not to turn the generator breaker on if the main breaker is on, so I guess that covers the electrician. And obviously with the panel cover on and the interlock installed properly this can't happen. My other concern was this was an old panel with a Bryant main breaker. It was fairly hard to turn off, (probably hasn't been thrown in years) to the point where I was hoping it would go back on. Now I'm worried HO might have a problem with it. Anyone had any callbacks or problems with these? Thanks.

 

[petersonra]

This almost sounds like an advertisement.

I don't think it is required but are these things listed?

 

[readydave8]

I used Bryant panels (the ones with color-coded breakers) for a while in the '80s, sometimes the main was hard or impossible to turn off, or on. I changed out several, don't remember having to change any twice so maybe it was just a bad spell?

 

[kwired]

This almost sounds like an advertisement.

I don't think it is required but are these things listed?

I don't know about the ones he describes, but the Interlockit's claim they are.

They are handy to use for older panels, most newer equipment has OEM kits that generally work better with them than the ones by these third parties, and often attach right to the breaker instead of the cover which I think is a good idea.

 

[qcroanoke]

I just installed 2 Square D interlock kits on HOM panels.
Piece of cake!
Ordered them from lowes along with 30 amp power inlets.
If you would like to see them search generator interlocks on Lowes site and they will pop up.
Was very pleased with them.

 

[Fulthrotl]

This almost sounds like an advertisement.

I don't think it is required but are these things listed?

i remember the discussion on here a while ago, and i believe they
have to be listed for the specific panel they are used on... at
least that is what was said here......

and a knock off of anything usually isn't listed... :happyno:

 

[hillbilly1]

They are a cheap and effective way to transfer power from utility to generator, but the one thing that makes me uncomfortable with them, and even kirk key set ups, is they are a mechanical only interlock. If the breaker fails to open on one or more poles, a possible back feed could happen. I have experienced multiple times where the breaker had not been operated in years where that has happened. A homeowner would not know what to do if anything when that happens, and I know a lot of electricians also that do not verify this in commercial applications.

 

[GerryB]

They are a cheap and effective way to transfer power from utility to generator, but the one thing that makes me uncomfortable with them, and even kirk key set ups, is they are a mechanical only interlock. If the breaker fails to open on one or more poles, a possible back feed could happen. I have experienced multiple times where the breaker had not been operated in years where that has happened. A homeowner would not know what to do if anything when that happens, and I know a lot of electricians also that do not verify this in commercial applications.

Very good point. I've had that with an old Sq D 100 amp. As I said this was a Bryant 200 amp and it was hard to switch. The interlock itself was specific for any panel with a bryant main breaker.
Apparently Interlok-Kit dosen't have a complete patent. As another poster mentioned depot and lowes carry a few brands.

 

[kwired]

I can't recall ever seeing a breaker that will not open if the handle will move, but I guess is possible, seen many that will not close

I'm sure whatever you may find at HD or Lowes is OEM and intended for the OEM product it was made for like Square D, Cutler Hammer, GE..., and not a universal type product.

When you get into the 150 amp plus main breaker in any of those product lines you will have an interlock kit that is designed to fit the panel as the mains are not all in same physical relationship to branch breakers from one brand to the next. The kits for 125 amp or less mounted side by side are the only ones that may physically fit more than one brand.

 

[hillbilly1]

I can't recall ever seeing a breaker that will not open if the handle will move, but I guess is possible, seen many that will not close

I'm sure whatever you may find at HD or Lowes is OEM and intended for the OEM product it was made for like Square D, Cutler Hammer, GE..., and not a universal type product.

When you get into the 150 amp plus main breaker in any of those product lines you will have an interlock kit that is designed to fit the panel as the mains are not all in same physical relationship to branch breakers from one brand to the next. The kits for 125 amp or less mounted side by side are the only ones that may physically fit more than one brand.

We do a whole lot of hurricane and tornado work, If memory serves me correctly, I have experienced one 400 amp breaker, three 1600 fused switches that have failed to open completely. Square D had a problem with the QMB series if I remember correctly, at sticking. The spring could not pull the blades all the way out, and would cock the assembly, with two opening, but a third still making contact.

 

[kwired]

We do a whole lot of hurricane and tornado work, If memory serves me correctly, I have experienced one 400 amp breaker, three 1600 fused switches that have failed to open completely. Square D had a problem with the QMB series if I remember correctly, at sticking. The spring could not pull the blades all the way out, and would cock the assembly, with two opening, but a third still making contact.

I have seen plenty of fused switches that do not operate, and if a transfer switch is built in a similar fashion can easily see transfer of say two poles while third remains in original position - not a good situation either.