Any electrical experts out here? Transfer switch + Sense question

Edit: This is for a 120V only generator.

I plan on having an electrician install an Interlock kit onto my electric panel. They will install a 30A 125/250VAC L14-30 inlet box on my house to a new 30A breaker for a proper 120/240V generator. My plan is to use one of those jumper cables that tie the two hots together so I can utilize both sides of the panel.

I am aware of the potential pitfalls of this. No 240V circuit breakers will be turned on (* except possibly one, which is my question below) and will have the electrician verify I have no MWBC’s in my house. We will remediate them as necessary.

So all that’s well and good. I think I did my homework on how to make this happen, but I have one caveat… my Sense monitor. I would prefer to keep this on when using my generator so I can see the power usage of that too.

My question is:
In light of the fact that I will be tieing both hot wires together from the generator, what would happen if I allowed this double pole circuit breaker to remain active for monitoring?

  1. Will Sense work just fine?
  2. Will it not work, even though the power draw is minimal?
  3. Worst case: Does something very bad happen by allowing a double pole breaker to remain active during this generator use? I assume the Sense monitor doesn’t bridge anything together, does it?

I don’t think the Sense device is a true 240V device, even though it requires that double-pole breaker. My concern is more about leaving a double-pole breaker active in this scenario. Also, will dual fed 120V lines hurt the Sense monitor in this way?

I’m not an expert but believe that Sense is a true 240, double pole device. I believe that it takes measurements from the CT’s and from the wires that feed the monitor for power.

Valnar: I can share with you what I have done this last spring. Close to what you are doing.

“My plan is to use one of those jumper cables that tie the two hots together so I can utilize both sides of the panel.”
DO NOT do this if you plan on feeding with a 220 volt generator. You can do this with a 110 volt generator, but not a 220.

Sense will not read your usage when you are ( I am going to use the term ) back feeding. Sense is seeing the ‘load’ from the meter and you are by-passing the meter. You are coming in on a breaker in the middle of the panel. Go the extra bucks and install a transfer switch. I did mine that way. That way you don’t have the mechanical interlocks on the breakers in the panel to deal with. I have pictures on my and can share them with you, but I this it is outside the realm of the board here. Also there are good videos on uTube of how to go about it. But I must warn you, if you are not comfortable around the panel with the cover off, let the electrician install the transfer switch.

Send me a PM and I will share more with you on my installation. Gerry

gcrawford.k8ger, see my other posts here. I’m new here so they are basically all related. It’ll answer some of your questions. If you see the cable I posted, it is for a 120v generator to a 120/240V inlet. I would be using the solar CT’s to watch the generator circuit breaker.

Robert… Yes… my mistake… After I sent my reply I saw it was a 110 adapter… I got your message in my email… Don’t think it was your personal email. I just did not want to flood the board with my pictures and verbiage that may not fit in. I will try to PM you later… thanks later… Gerry

Thanks, but I’m good on 99% everything I need to know. I’m not asking how to install a transfer switch or interlock. I’m basically asking if the Sense monitor (and my house) will be okay with the Sense monitor’s 240V double-pole breaker active.

ie. Will it be hurt by the ‘split’ phase essentially being in sync as opposed to 180?

I guess that’s more of an electrician question than a Sense community question, but this in regards to the Sense device specifically.

Robert: Sense will only ‘read’ from where the power is being ‘fed’ from. The flow of power…In other words if the power is coming in from the meter and and you have the Sense CT’s on the legs coming into the circuit breaker box, Sense is going to read it from there. ie, as normal… When you flip your interlock on your 220 breaker, the power is taking a different path in through to …say… the middle of the panel and Sense does NOT pick up that path. ie, There is not a path/flow of power from the meter to the CT’s… Must have current flowing through the wires the CT’s are connected/surrounded… Hope this helps and answers your question. If not, steer me again… Sorry I am getting old… Hi … Gerry

BTW… Do not move the CT’s once you have your system calibrated. It will throw the whole system off…

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Gerry is correct.
You would also ha e to make sure the breaker that Sense is connected to is “Downstream” of where the generator is.
If you were looking at your panel and your main worse are fed from the top, the Sense breaker would have to be below the generator breaker.

I would be using the Solar CT’s on that breaker. It would be the source of all the generator traffic.

Robert: Still hoping I am helping. I will post pictures of my transfer switch and plug for the power input from my generator and/or solar output. My plan is to output my solar power into my transfer switch when I am not in power failure. Looking to build a battery box housing the inverter ( 220 at 48 volt ) to output in the transfer box plug. My transfer switch is a … http://reliancecontrols.com/ProductDetail.aspx?310C … 30 amp. It has 2 - 220 circuits. One for my hot water heater and the other for my well pump. Then it has 5-6 110 circuits. With the output going into the transfer switch from the solar output, I can turn on/off circuits to trim… if you would… the current draw from solar to line power not to overload my batteries. I have the frig, computer, wifi, tv, lights etc on the 110 breakers. Now… you talked about jumping the 220 lines … Or something… you can do that with a plug and run all these 110 circuits from a 110 volt generator. I have a cable made up to run the 110 circuits overnight. Just turn of the 220 circuits. This way you can run the frig etc overnight on a smaller generator.

I have 2 of the Honda generators… EU2000 and the new EU 7000 IS. This is an inverter type with fuel injection and is claimed to be very efficient. Quieter then the 2000 series models. Very nice generator. This is a second ( or more ) generation generator. The fuel injection is the latest upgrade.

Now… My experience with batteries and inverters… Just in case. For 20 years I have been powering my shop/barn… 42 by 60 with over head lights and small electric tools… Table saw, drill press etc. use it to charge batteries on my tractors and do small repairs. Have 2 circuits of 110. One for lights and the other for plugs. the inverters are Stat Power 110 volt / 12 volt. Charge the batteries continuously while I am using them with a Iota 75 amp battery charger off Honda EU2000. 3 - 12 volt deep cycle batteries in parallel. Enough

for now… Later…Gerry