Home Forums General Discussion Technical Questions Older Dover need part rectifier identified

I have an old Dover elevator and no prints. Vertical Express can't find the prints even though I have a job number. The issue I have is, I've troubleshot the problem to a rectifier, (not getting proper voltage to a relay coil) but I can't identify the actual rectifier. I've attached a picture, any help is appreciated.

Thank you
Stephenie

try reaching out to cougar electronics in New Haven CT.
https://cougarelectronics.com/power-conversion-components/selenium-rectifier-suppressor/

Do you know what the output voltage is supposed to be? Maybe you could go with a switching power supply.

Thanks, I'll do that tomorrow.

115 vac or dc, I'll have to check with my tech. I'll see about switching. Thanks.

I could be wrong, especially because I can't see what else is going on, but from the picture I'd guess they're taking three phase and making DC. Is that right? Old rectifiers like that get leaky and weird. Can you just replace them with big silicon diodes? If the circuit is fused, you can get an idea about the current capacity of the diodes you need. If one of them is truly your problem, I'd replace them all.

That part is definitely the issue, we won't be able to make it back to the job until tomorrow. Thanks for your information rustyiron.

Also depending on how much the voltage has decayed, if these are the main supply, look for higher voltage is you replace them with solid state. If they supply Gen Fields car could run quite a bit faster. Be careful, safe, and prepared. check car speed. If its for doors, door speed will change with solid state. New units are solid state with supressors to protect inverse voltage from relay inductive kicks and coils.I think Adams sells a replacement made with supressors.

That’s why I suggested a power supply. To avoid any voltage level differences between the old selenium and new silicon.

Have you checked your capacitor between PC and 24D? Majority of my problems with dover's not getting correct voltage to solenoids has always been that booster capacitor. With not enough power to feed the relays those elevators start doing all sorts of weird stuff. Haswell your power board might not be putting out the correct 5 volts DC

Thanks again for all your help.

These are selenium rectifiers, this Dover assembly is obsolete but the rectifiers we can get. I contacted Cougar Electronics, i sent them dimensions so I will be able to get the rectifiers from them, we'll just be replacing the 3 rectifiers. I also contacted PSI (parts specialist inc) they had 4 in stock, but they were nearly $100 per rectifier, quite a bit more expensive than Cougar Electronics.

Thanks again guys,

Stephenie

Those rectifiers do not look or appear to be Mainline. Due to the wire gauge. Probably coming off a Transformer. You should be fine replacing them with the $8 silicone rectifiers. Just throwing a lot of money at Old technology