Rocker arm transfer mechanism for breaker serving a portable generator

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tonype

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1st time ever seeing this. Is this type generally approved? I am used to see more substantial means to accomplish this.
 

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tonype said:
1st time ever seeing this. Is this type generally approved? I am used to see more substantial means to accomplish this.
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They have been building this type of interlock for almost 50 years. It is a UL recognized device for use in UL Listed load centers.
 
While it does serve the purpose and I don't have an issue with using it, some inspectors will not permit it because 702.5 requires the use of "transfer equipment". The interlock device has all of the required functions of "transfer equipment" but is not listed as "transfer equipment". Check with your AHJ.
 
Hope that welding receptacle isn't used as a power inlet!
And what branch circuits are we transferring power to .... Don't see any.
 
If this is being used for a generator transfer switch, they work well. BUT, it doesn't switch the neutral. So one would have to remove the N-G bond in the generator. That's what all the fuss was about on the recent art 445 thread and one a few months back where JW took exception with removing the gen NG bond and using a two pole transfer.

I've got one at my cabin to switch between the gen and an inverter - works great.

ice
 
mopowr steve said:
Hope that welding receptacle isn't used as a power inlet!
And what branch circuits are we transferring power to .... Don't see any.
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Follow the wire from the CB out the top, to the left, down to the receptacle. 240V with a neutral to a 3W receptacle - no EBC.

So does the power come in on the lower right and the two CB direct power to either the receptacle or other (center top).

Or, does the power come in on either the receptacle or other (center top) and switched to feed the lower left.

Can't tell.

ice
 
It looks like the smaller wires exiting lower right are the load.
Based on the smaller wire size the output may need to be treated as a feeder or branch tap.
And yes, the welding outlet appears to be a disaster waiting to happen.
 
don_resqcapt19 said:
While it does serve the purpose and I don't have an issue with using it, some inspectors will not permit it because 702.5 requires the use of "transfer equipment". The interlock device has all of the required functions of "transfer equipment" but is not listed as "transfer equipment". Check with your AHJ.
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I can't find where 705 says Transfer Equipment must be "listed" as such? (Unless it contains supplementary overcurrent protection)
 
shortcircuit2 said:
I can't find where 705 says Transfer Equipment must be "listed" as such? (Unless it contains supplementary overcurrent protection)
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The rule in 702.5 requires the use of transfer equipment. There are no markings or other information that tells you the breaker interlock is transfer equipment. If it is not transfer equipment it does not meet the rule. Again, it has the functions of transfer equipment and many inspectors are ok with it, but some are not.
The rule should be changed to specifically permit the use of a breaker interlock as transfer equipment.

I used the term "listed" as that is one method that the inspector can use to "approve" equipment. Many inspectors do not approve things that are not listed for the purpose.
 
don_resqcapt19 said:
The rule in 702.5 requires the use of transfer equipment. There are no markings or other information that tells you the breaker interlock is transfer equipment.
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I disagree with that.

The section does not require listed transfer equipment therefore anything that is designed to prevent the connection of both sources meets that code section.
 
mopowr steve said:
Hope that welding receptacle isn't used as a power inlet!
And what branch circuits are we transferring power to .... Don't see any.
Click to expand...
Sure looks like the receptacle is likely the standby power inlet to me.

What circuits are supplied, the left breaker is probably normal power input, the right breaker is probably standby input, the main lugs of the panelboard are supplying the load as they are the "common point" of the "transfer device"
 
iwire said:
I disagree with that.

The section does not require listed transfer equipment therefore anything that is designed to prevent the connection of both sources meets that code section.
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Everything has to be "approved" per 110.2. A number of inspectors will not approve the use of the interlock as "transfer equipment".
 
don_resqcapt19 said:
Everything has to be "approved" per 110.2. A number of inspectors will not approve the use of the interlock as "transfer equipment".
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I understand that as well, doesn't mean I always agree with inspectors though.

I will be asking for a meaningful explanation of why they don't accept something, "that is just the way we do it" is not acceptable to me.

If something is not listed for a particular purpose - that is fine, next step - does NEC require it to be listed?
 
As already stated, check with your AHJ. The inspector I generally call (we have 3rd party inspection agencies) will approve an interlock provided it is listed for the particular brand breakers/panel it is installed in.

The one in the picture may or may not be listed for square D.
 
mjf said:
As already stated, check with your AHJ. The inspector I generally call (we have 3rd party inspection agencies) will approve an interlock provided it is listed for the particular brand breakers/panel it is installed in.

The one in the picture may or may not be listed for square D.
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It may or may not be listed, it is not listed "transfer equipment".
It was certainly designed to fit the QO series breakers and will not fit anything else without modification because their design is different enough then anything else to be able to fit.
 
It also looks like a single lug was used for multiple ground wires in the upper left corner, instead of a ground bar.

The single lug is likely not listed for multiple wires.

Is the panel Bonded?

The 2 pole breakers would also be considered mains so a main hold down would be required also, correct?

Seems like there are many violations with this setup if its being used as a generator panel.
 
kwired said:
Sure looks like the receptacle is likely the standby power inlet to me.

What circuits are supplied, the left breaker is probably normal power input, the right breaker is probably standby input, the main lugs of the panelboard are supplying the load as they are the "common point" of the "transfer device"
Click to expand...

That's exactly the way I see this also.
Need to worry less about the transfer capabilities of the setup, and, more about the " Double Male Ended" cord they'll have coming out of thier generator that's going to plug into the outlet to feed it.

JAP>
 
There is probably incorrect equipment grounding other then the two conductors in the lug issue as well. Doesn't appear to be an EGC to the generator at all, and if neutral is bonded in the generator then don't we need to switch the neutral?
 
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