Electrical – Four transfer switches do not seem sufficient to control numerous appliances through 120v panel breakers

electrical-panelgenerator

I am trying to hook up Honda 7000 to a Reliance transfer switch (just using their manual at the moment). The setup requires balancing the 120 volt loads among 3 transfer switches for each side of the generator. Two switches are ganged together to get 240v for my water pump leaving only four 120v. transfer switches. It appears that 2 switches on each side can be used to balance the left and right sides of the generator (22.9 amps, 5,5K watts @ 240v is maximum total output). So there are 4 switches left to handle all the 120v appliances, receptacles etc. Each switch seems to be wired to one 120v breaker in the house panel. Unfortunately, there are NOT four 120v breakers in the house load panel that are house-wired up to all the things I would like to run.

****Additional Info:
Wow. Did not expect answers so quickly. Great answers. I have not actually purchased a transfer switch yet. I downloaded a Reliance 31406CRK manual and was tracing out how it might work. I got more and more concerned that it would not work very well for me. Then i found this website. Glad I did, although it will take a while to become familiar with it.

For over 25 years I have ignored the admonition to not back feed the generator through the panel. I have clearly marked the panel to "switch the power company switch off before doing anything." Then, hook up the generator and flip the breaker for the generator. The power company has done work up here and they have seen the generator (even changed their meter) and never said anything about it. It has worked perfectly many times until last month I had to have the 3 hp water pump replaced. They put a pump saver device on it and the next time I used the generator the pump would not run. My Devilbiss 7000 generator was putting out 268v. for some reason (another problem to solve) and the pump saver said NO.. I had to turn on several "burners" on the electric range to get the generator's rpm down to lower the voltage and the water pump took off. In the mean time I bought a Honda EU7000is.

I thought, maybe with the new generator, it would be safer to have a transfer switch interlock in case someone else has to engage the system. In my internet search I did not see the interlock device of which someone sent a picture (I can't see who at the moment, but much thanks). That device would provide considerable protection against any confusion. I will have to rearrange my breakers a little, but fantastic solution.

It seems as though two people responded to my question if I am reading this right. I thank you very much for your time and thoughtful responses.

It is still not clear to me how the two 120v phases from the two halves of the generator (to make 240v) end up balancing the full power of the generator by distributing what is left from the 220v water pump to the other 120v breakers, which may be on or off depending. I am hooking a watt meter up to each leg. Maybe that will show what is going on.

Best Answer

NO, you can't do that. That would cross connect circuits which could lead to overloading the neutrals. While you haven't said, I think the type of transfer switch you have is something like the pic below.

We hate to say it here, but those aren't all that great. They are expensive and limited in capacity. Many here prefer a power inlet for the generator, wired to a breaker with a mechanical interlock with your main breaker on your main panel. The obviously vary by panel but you can get a rough idea from the 2nd pic. Taking this approach allows you to pick and choose which circuits to run off the generator by turning off or on various breakers. It's code legal and safe, convenient and not expensive.

EDIT: Thinking about this for a few more minutes, your idea is a really terrible one. You'd have cross connected circuits and the end result is to do any kind of maintenance you'd have to turn off multiple breakers to depower a circuit. PLEASE don't do this. Others have commented just now saying a mechanical interlock is best and ironically, least expensive. As 3ph said, please shoot us a pic of your main panel to better help you.

transfer switch

interlock kit