Transfer Switch Crapping out???

[pharmafrog]

When our genset spins up and tries to kick over to AC there is a rumbling in the belly of our 4100. It sounds like there is a solenoid or relay trying to trip but not clicking over all the way. After a short time it catches, but it can take a few tries. I can hear the genset start to kick up RPMs and then the rumbling and the genset settles down for a bit before trying it again.

Transfer switch?? I want to get this taken care of. Brand new 4100, as well.

 

[danemayer]

Hi pharmafrog,

When you fire the generator, I think it should take about 25-30 seconds to stabilize the genny output before the transfer switch tries to activate. If the generator is supplying 120V on L1 to the transfer switch, the contactors will activate which should produce a solid clunk sound. If instead you're hearing chattering, the contactor is failing and the transfer switch probably has a loose connection or needs to be replaced.

 

[jbeletti]

I agree with Dan on this. I had the same thing happening. Loud chattering. Replaced the transfer switch under warranty and no more chattering.

 

[scottyb]

Check the J-box outside the generator. After replacing my 2nd ATS in 10 months, I was getting intermittent voltage across the new switch. I chased it back and found poorly landed wiring in the J-box. The neutral had just a few strands making contact, and the wire nuts on all of the wires were very loose. There was also some charring on the wiring, probably from arcing. This was possibly the cause of both of my ATS failures. I know od at least a couple others who have discovered the same thing on their Cyclones.

 

[hoefler]

Also, make sure you don't have any high draw appliances on, A/C, water heater, etc.. The high draw items will cause a sudden voltage drop when the switch is trying to switch over, dropping voltage on the relay signal lead, causing the switch to drop out, chatter.

 

[Lou_and_Bette]

Another thing you might want to do is flip gen breakers off until gen is up and running,especially if still connected to shore power. A gen I had at home, lived on Miss. Gulf Coast, had a sticker that instructed not to connect anything until gen had been running 5 minutes. I think that allows gen to stabilize current before load is applied.

 

[danemayer]

The ideas on letting the generator stabilize and turning off loads are good practice that may help the system work better and avoid problems, but the transfer switch should not chatter whether you do these things or not.

 

[wdk450]

If you want to reduce initial load (and contact wear) on the transfer switch, I would recommend flipping off the main breakers in the trailer breaker box, turning on the generator, and then turning on the main trailer breakers. This should put the initial load surge contact arcing wear on the easy-to-replace main circuit breakers, and not on the hard to find, hard to access transfer switch relay.

 

[branson4020]

Also, make sure you don't have any high draw appliances on, A/C, water heater, etc.. The high draw items will cause a voltage sudden voltage drop when the switch is trying to switch over, dropping voltage on the relay signal lead, causing the switch to drop out, chatter.

Yes! This just happened to me last week. Shut down generator without turning off the Air Conditioner. When we went to start it up again, transfer switch would not engage until I shut off the air.

 

[Jim.Allison]

No chatter just clunk........