Need help finding an electrical component

[R_Lefebvre]

It sounds like solenoid that you linked to would take 750A to make the circuit, and would not be energized below 100A? Doesn't seem right... I bet I'm understanding this wrong.

No, that's not right at all. I believe what they mean is the solenoid can handle 750Amps at the instant contact is made, such as switching a large motor with a huge inrush current when it starts up. Once running, it can only break 100Amps. Above 100Amps, the current might arc across the contacts and not be able to shut off the load.

I see this with situation with motor contactors in an industrial setting, particularly in an E-stop situation. It's something I have to design around. When the E-stop button is pushed, our motor controllers go into a fast stop mode, and dump large current back into the power grid. If we get things wrong and the contactor tries to open when this is happening, the current arcs right across the open contacts. Makes for a great sound and light show! We must design the system so that the contactors only open after the motor controller has finished braking.

 

[GlennA]

What kind of relays are you using for that kind of load? I looked around a bit (admittedly, just a quick look), but didn't really see anything that I thought would work.

It sounds like you're in a situation similar to mine, where you want to be able to run 100A if you have a reason, but that the typical load will be significantly less.

Look Bosch relays 0 330 002 150 and 0 332 002 156 on http://www.texasindustrialelectric.com/relays.asp. That is what we normally use. We currently stock the Tyco version p/n V23232-D0001-X001.

To connect a #4 wire to the relay, a trip to an electrical supply house will yeild #4 uninsulated ring treminals. They will likely require a specialized crimping tool. Solder and heat shrink and they are ready.

We mount these relays under the hoods of heavy equipment, ie dump trucks, flat beds, motor graders etc. We also have pickups with over 200K miles and these relays mounted under the hood.

I probably wouldn't mount them under water, but they have proven to be water resistant. Admittedly, we don't have much use for salt on the roads around here, so I cannot speak to their performance in a highly corrosive environment.

 

[WhereTheHellIsJames?]

Look Bosch relays 0 330 002 150 and 0 332 002 156 on http://www.texasindustrialelectric.com/relays.asp.

Thanks for the link, but it looks like both of those Bosch units are rated at less than what my spec is.


I think that something like this Nagares relay that I found on eBay is what I'm looking for. I contacted the seller, and they informed me that they will not ship to the US. On top of that, I haven't been able to find a source for one in the US anywhere. Anyone on the other side of the pond want to help me out?

 

[tremors834]

Check the power relays or the Continuous Duty Solenoids. I've ordered many from this site.
Relays and Solenoids
What kind of project do you have in the works???? :coffeedrink:

 

[GlennA]

Thanks for the link, but it looks like both of those Bosch units are rated at less than what my spec is.


I think that something like this Nagares relay that I found on eBay is what I'm looking for. I contacted the seller, and they informed me that they will not ship to the US. On top of that, I haven't been able to find a source for one in the US anywhere. Anyone on the other side of the pond want to help me out?

Try from the Waytek site.

http://order.waytekwire.com/productdetail2/M37/75551/POWER RELAY 12V SPST 100 AMP/