Generator and transfer switch dilemma

Generator and Gen Switch Box



My TroyBilt Generator 10.5kw/7kw generator has a statement in the owners manual under “System Ground”: The system ground is connected to the AC neutral wire (the neutral is bonded to the generator frame).



I recently installed a Connecticut Electric Generator Transfer Switch kit 10-7501G2 to my home breaker box; and followed the instructions to the letter. Ditto for running the permanent wiring under the floor to my outside power box.



8 of my 10 gen switches are connected to 15 amp/120v circuits. The remaining 2 are wired together 240v to power my central a/c. My a/c service tech assured me this generator would run the a/c but NOT the heat side.



Having completed all phases of wiring, etc… I flipped the 200 amp breaker providing utility service to our home. Everything works as before and I let the system run overnite to be sure.



Today, I flipped off the main breaker, turned on my generator, hooked up my L14-30 cable, and began switching circuits from “line” to “gen” one at a time. I started with the 240v circuit, but the a/c did not power up. I then went through all 8 remaining circuits and checked the house for power. Everything on all 8 circuits was powered up just fine.



The LCD panel on the a/c thermostat was blank as if no power. My generator is showing only 34% usage and the meters on my gen xfer switch are indicating power usage on both legs.



I go back to my transfer switch instruction manual and read: This product is suitable only for use with a generator with a floating neutral… contact generator manufacturer for instructions to remove bond between generator neutral and frame.



Does anyone in the forum have any useful ideas on what I can do to salvage this situation?

Please reply in the forum or PM me.

 

Welcome to the forums.

You don't want your email address posted on a busy website like this one.
You will get email notifications of a reply.

If you have a heat pump system or an A/C with electric heat..... you will have two 2P 240v breakers. One for the outside condensor and one for the inside air handler.

 

Not sure why this thread closed. I reopened...

 

You cant have two bonds.. If your using the gen for home power as you state you need to lift the bond at the generator..

Call the manufacturer to ask how...

Check the wiring on the furnace end after you unbond gen..

Many furnaces today require correct polarity to the control board. The control board determines this by checking voltage from hot to neutral and hot to ground.

 

Have you checked to be sure you have 240 volts on the load side of the breakers in the transfer switch?

 

You need to use the RECOMMENDED type of transfer switch the manufacturer of the generator says to use and only make modifications to the generator the manufacturer approves.

Quite a bit to all this. There are neutral switching and non-neutral switching transfer switches.

Further reading... Search google.com for "separately derived system" and "non-separately derived system"

 

thanks for the welcome and removing my email. and you are correct. the 45 amp breaker just above the a/c is the 2 pole heat side of the system; and when i flipped it off, the LCD panel in the house went blank... just like it did when i tried to power with the gen/ my xfer switch instr tells me to NOT connect any breaker above 30 amp... so i guess my hope of having a/c during hurricane outage is gone.. plus the wires coming off this breaker are HUGE. thanks again for your help

 

thanks for your input. based on the limitations (30 amp) of my transfer switch kit, i have abandoned the hope for central air during summer outages

 

i am unable to reconnect the gen until the heavy rains stop. but what i can tell you is that BOTH sides of my gen transfer switch were supplying power to 8 circuits in my breaker box. AND both watt-meters were registering current flow during the one-hour test i ran. dont know if i had a full 240, but everything in the house was working properly, 2 frigs, 1 freezer, microwave, etc

 

thanks Bill, i have read a mountain of online info on articles related to your reply. i think i am going to try to get an electrician to come out and see if he can salvage this. if i have to purchase a different xfer switch, i may use this one as a power center in a remote garage i am about to order. the gen would be the only source of power for my lights, compressor, etc.. all 120vac needs.

 

Yes.... it's the heat and the air handler. You can connect that to your generator. The air handler in blower mode(A/C) only uses a few amps. The breaker is that large because of the backup electric heat coils which you won't be activating.