Being I hadn't run the generator in quite a while, I decided to run the generator this weekend to exercise and make sure all was in working order. Generator fire up and ran great, turned on living A/C and then the garage A/C, all good. Let it run for about 2 hours, then decided to switch to the bedroom A/C, flipped the switch to middle position to turn off living A/C, then switched over to bedroom A/C, hear loud clicking from transfer switch, generator loaded up, then unloaded, then bedroom A/C turns on. Went back to gargage and its not running. Turned everything off and then powered down generator, checked generator and it had tripped one leg on the 30A breaker which obviously powers the garage A/C. Plugged back into shore power and all is working fine. Anyone have any ideas on what may have happened?
Generator/Transfer Switch Question
- Thread starter machete31
- Start date
danemayer
Well-known member
2 possibilities come to mind.
1) Something else was drawing power on that leg when the bedroom A/C kicked on. At times the Power Converter can draw > 15 amps. If the water heater was running on electric, and something else was on, you might exceed 30 amps on that leg. The generator loading up might be consistent with this theory. The chattering suggests a voltage fluctuation on L1 from the generator.
2) You might have a loose connection on L1 from the generator into the transfer switch.
1) Something else was drawing power on that leg when the bedroom A/C kicked on. At times the Power Converter can draw > 15 amps. If the water heater was running on electric, and something else was on, you might exceed 30 amps on that leg. The generator loading up might be consistent with this theory. The chattering suggests a voltage fluctuation on L1 from the generator.
2) You might have a loose connection on L1 from the generator into the transfer switch.
Flick
Well-known member
My vote goes to #1. Probably will all be ok next time run. Just make sure everything is off and turn things on one at a time.
Thanks for the input!! I'm gonna agree that some of #1 is the culprit. Water heater was off and power converter was on, thinking maybe when I switched to bedroom A/C the load on the generator dropped the voltage to the TS and it caused the garage A/C to turn off/on quickly and then I had both A/Cs trying to start together and the garage A/C leg tripped...more resistance due to distance to the back of the unit?? I'm gonna run again and turn on bedroom A/C first then garage second and see what happens.
wdk450
Well-known member
Motor startup current for the AC could be the problem, can be about 10 times running current, and not an exact repeatable amount every time. The breakers on Air Conditioning loads are supposed to be air conditioning rated to take this big overcurrent for a few seconds before finally tripping.
Right now I would chalk this up as a 1 time thing; if it reoccurs I would consider installing easy start-up capacitors on the AC units. Maybe even changing out the breaker involved since these cannot be easily tested for the time delay function.
Right now I would chalk this up as a 1 time thing; if it reoccurs I would consider installing easy start-up capacitors on the AC units. Maybe even changing out the breaker involved since these cannot be easily tested for the time delay function.
danemayer
Well-known member
Something else comes to mind. The Onan 5500 generators come with 2 circuit breakers located on the front of the genny. Many have one 30 amp breaker and one 20 amp breaker. Some models have two 30 amp breakers. If one of the breakers on your genny is a 20 amp, hopefully that's not L1.
If the problem recurs, I'd suggest disconnecting power and checking the connections in 1) the transfer switch, 2) the junction box located by the generator, and 3) the backside of the main breaker panel. You may also need to look into how the loads are balanced in the breaker panel. Our Electrical user guide can be helpful as you go forward.
That happens with my TS as well. Simple dropout of the Generator transfer relay with low voltage. My Convertor can draw 12 to 15 amps when batteries are low.
