Essex 427 loadbank

[Mk23]

My loadbank I've had for several years quit working last weekend. Today, I had the time to open her open. All the basics check out. Checked the contactor. Moves freely and there is 24v at the coil, but it's not kicking in. Little electromag give up the ghost? Very carefully with isolated screwdriver, I can manually kick in the contactor and everything else works. Gen feeds the loadbank. Then I turned it off, using the On/Off toggle. So Everything else checks out.

It's a Eesex A807-1501 contactor. There are some for sale on Ebay for a cool $1700. Was looking for a cheaper solution.

Is the little magnet serviceable? Should I just look at a commercial contactor?Advice appreciated

 

[DieselAddict]

Any generic 100A 3 phase contactor that fits should solve the problem.

 

[155mm]

Had the same problem with a umc 33kw, just used an off the shelf magnetic switch, had to get a base, then added the sized switch i needed on top.

 

[Guyfang]

Are you sure its the magnet? 100% sure? what did you do to troubleshoot?

 

[Mk23]

Are you sure its the magnet? 100% sure? what did you do to troubleshoot?

I am never 100% of anything in life...

That being said, there is 24v at the magnet with the loadbank turned on. It's not retracting. I also used a separate 24vdc source, with everything else off, straight on the magnet, its not doing anything at all...

I took that as an indication it's the coil. Did I miss anything?

 

[Mk23]

Had the same problem with a umc 33kw, just used an off the shelf magnetic switch, had to get a base, then added the sized switch i needed on top.

So you are saying taking at apart and see if I can source a magnetic switch then? Where did you get yours?

 

[155mm]

this is the one that I replaced mine with, but I had information on the old magnetic sw to compare my new one to

https://www.amazon.com/gp/product/B00EZ1Q9VE/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

 

[Guyfang]

That sounds right. Most of the problems I saw, were due to the cooling circuit safety switch not allowing the CB to close. But if you have use separate 24 volts to test it, then you have it right.

 

[155mm]

@Mk23

I did have a complete wiring diagram on mine and spent a good day chasing just to make sure I didnt miss anything before I started to replace the switch. The size was different so I had to replace some of the wires. While troubleshooting, I did find a rectifier that did not test correctly and replaced it first, but it didnt fix my problem so I dont know if one failure caused the other failure.

 

[Mk23]

That sounds right. Most of the problems I saw, were due to the cooling circuit safety switch not allowing the CB to close. But if you have use separate 24 volts to test it, then you have it right.

Great, thank you. Anyway to find out the Amp rating on this contactor? A807-1501, I have searched high and low and couldn't find specs

 

[DieselAddict]

A 100 amp contactor will handle ~36kw at 120v which exceeds the 33kw capacity of the load bank.

 

[Guyfang]

 

[Mk23]

Thank you!