120 volt generator connection.

[Naterade21]

Putting in the 125/250 4 wire inlet also allows for easier integration of a larger generator down the road - but consider a 30 amp instead of a 20 amp inlet, if/when they decide to go bigger they probably go to something with 30 amp output receptacle.

Although the mains are switched off at the breaker while the generator is activated with interlock activated, the neutral in these systems is un-switched and still shared with the upstream neutral power line, correct? Would this not pose a hazard to power line workers working on lines, or are they safe / unaffected? Going based off this rough illustration: http://www.interlockkit.com/typicalinstall1.htm

 

[kwired]

Although the mains are switched off at the breaker while the generator is activated with interlock activated, the neutral in these systems is un-switched and still shared with the upstream neutral power line, correct? Would this not pose a hazard to power line workers working on lines, or are they safe / unaffected? Going based off this rough illustration: http://www.interlockkit.com/typicalinstall1.htm

The grounded conductor is still grounded everywhere upsteam in the POCO distribution. Only way you present a hazard is to back feed at least one ungrounded conductor plus the grounded conductor. If you back feed a single ungrounded conductor and nothing else you don't have a complete circuit through the transformer and no current will flow. If no current flows it can't transform any voltage on the other side.

 

[Naterade21]

Thanks!

 

[don_resqcapt19]

We have a rule in MA that requires the inspector to accept listed equipment when used per its listing.

And that is the issue. The code requires "transfer equipment" and these devices are not listed as transfer equipment.

I don't see an issue with their use as they provide the required functions of "transfer equipment", but since the NEC requires transfer equipment and breaker interlock kits are not so listed, some AHJs do not accept them.

 

[jumper]

I would rather see an interlock kit than most of the suicidal/homicidle DIY set ups I have seen.

 

[qcroanoke]

Putting in the 125/250 4 wire inlet also allows for easier integration of a larger generator down the road - but consider a 30 amp instead of a 20 amp inlet, if/when they decide to go bigger they probably go to something with 30 amp output receptacle.

Also you need to put signage at the inlet warning that the 2 hot inputs are tied together in the inlet and that the jumper must be removed if the existing generator is replaced with a 120/240 input genset.

 

[goldstar]

I have just about the same setup at my own house so I can run off my Honda 2000 genny. It works great so long as I manage the breakers properly. I have to shut everything off and turn on the breakers to the fridge, freezer, and whatever else might be running, at separate times. I would never do it for a customer though. Too many things to understand and remember. My experience has been that if they are capable of understanding and remembering that much, they probably wouldn't be calling me!

Managing the loads is a big part of this and also a difficult concept for a novice to understand. You might be willing to turn on your fridge for an hour or so and leave off your well pump or your heat (if you're in a cold weather area). However, most of these types of customers do not want to be inconvenienced in any way and will usually not manage the loads properly.

Stop and think about this - your customer has a 200 amp 120/240 volt electric service - he has a 2000 watt generator with a 120 volt (only) receptacle and wants to run his entire house. Now he wants you to figure out a way to hook this generator up so he has the convenience of running just about anything he wants. You're going to spin your wheels trying to accommodate this customer when the easiest thing to do is to buy a new generator with at least a 30 amp 120/240 volt power outlet with a listed panel interlock kit.

IMHO - a no brainer !!!

 

[kwired]

Also you need to put signage at the inlet warning that the 2 hot inputs are tied together in the inlet and that the jumper must be removed if the existing generator is replaced with a 120/240 input genset.

Jump the two "hots" together in the cordset somehow and and you won't have a problem later.