PD transfer switch issue

[racer0624]

My PD 52 won't switch over to generator. We've been on shore power for 2 months. I'm wondering if it might just be a stuck contact. Any ideas?

[twinboat]

Did you check the generator circuit breaker ?

It needs to send at least 90 volts power to the ATS for It to switch over.

[amosnandy]

Originally Posted by racer0624

My PD 52 won't switch over to generator. We've been on shore power for 2 months. I'm wondering if it might just be a stuck contact. Any ideas?

First a disclaimer. If you are not experienced or are uncomfortable working with 120/240 voltage have repairs done by someone who is. That said there are several things that are easy and safe to check.

First thing to check is the breakers on the generator. There should be two either on the right side or the front. If you started the generator under load they may have tripped. Make and model of generator would help

Transfer switches come two way. One is shore power priority, the other is generator priority. I've had both and since yours is working on shore power, I would guess that is what you have.

It would be helpful to have the make and model of the transfer switch.

Where I would start is with power and generator off. Take the cover off it. Check for burnt wires, loose grounds into the buss bar anything that looks abnormal.

Next, still with power off you should be able to see the magnetic relays on the ATS. One should be out, the other in. Push on them both and see if they move. The magnet or relay may have failed. I had one that was shore power priority, and had no generator power. I could push the relay in and the generator would energize. As soon as I let go it would stop.

Some newer ATS these are completely enclosed. Then the only thing you can do is determine which line in is for shore power and which is for generator. Start the generator, get your VOM out and test voltage between one line of the generator in and the ground. Check both sides. Now check the voltage going out. If you have generator power going in but not out your ATS has failed.

Newer ones are a little more complicated as they have some electronics in them but they come as a complete non repairable unit. You just take it out and put a new one in.

It is very rare that contacts would stick. Especially since you have been on shore power. Turn your shore power off and back on with the breaker at the pedestal and you should hear an audible click. My newest one makes several noises. I'm assuming that is the electronics determining what sort of power it has coming in.

Most of all be careful.

[Dutch Star Don]

Whack the transfer switch box a couple of times with a rubber hammer or other rubberized tool, like a hammer handle. A good whack will often unstick the contacts.

[racer0624]

DUH!!! The circuit breaker was off. I've embarrassed myself. [emoji15]

[twinboat]

Good thing you didnt start beating it with a hammer or ripping it apart first.

[C.Martin]

My PD52 ATS developed a problem. I ordered a new one…and installed it. Then tested the original one, once I had it removed. The problem occurred after I had re-torqued the contacts. The generator breaker would trip anytime I started the generator, while shore power was connected.

My transfer switch is Generator priority. It is designed though…not to allow the generator to take over until the shore side is disconnected. I don’t mean that I have to physically disconnect the shore power…I just mean the relay for the shore side has to open before the generator relay can close. The two relays have a mechanical interconnect situated between them. Mine was not working. All of the components inside my box were functioning. The problem is that during assembly…the installer mis-positioned one of the plates that hold the relays to the box. There is an A side and a B side. The wider of the two is designed to capture the top side of the two relays…the narrower side is designed to hold down the bottom of the relays. When mounting the relays…you have to properly align the mechanical interconnect that is sandwiched between the two relays. By mounting my relays with the wide side on the top and bottom..I was able to slightly twist…unbeknownst to me…the bottom of the relay when I was re-torquing the contacts. The interconnect pin got misaligned and was not functioning. This meant…when I fired up my generator…for a brief second…the Generator and Shore were able to simultaneous connect…and this tripped the generator breaker every time. I need to go back and remove my new transfer switch…I think it was put together incorrectly as well…I just haven’t twisted the relays enough to drop the interconnect pin.

If you find your generator breaker trips every time you start while connected to shore power…you may be experiencing the same issue. For the time being,.Lyon can just get in the habit of disconnecting the shore before you start the generator. When you get a chance…you can tell the relay out, and check for the way they fastened the relays in…and see if the interconnect got misaligned over time. Easy fix…if you know about it.

It’s a very simple design…but for some reason, their quality control stinks. Be on the lookout for incorrect use of mounting plates in your PD52 ATS.