DIY Electric Car Forums banner

Do Sealed Contactors Need Snubber Diodes?

667 Views 1 Reply 2 Participants Last post by  kennybobby
I'm trying to replace a very old Albright contactor, the kind that is open to the air and is a possible museum piece, with a new Gigavac GX series sealed contactor.
The Albright uses a diode to absorb inrush currents. The Gigavac documentation says no diode is necessary. But deep in the documentation it does mention that some customers with Curtis controllers have had issues. I have a Zilla. Because the contactors are sealed, there's no way I see that you can add a diode.
So, if you've got an old-school controller with giant capacitors can you use a modern sealed contactor? Or do you have to work around it?
Thank you.
1 - 2 of 2 Posts
The diode is not likely for inrush, but for freewheeling current on the COIL. Any switched current into an inductor needs some sort of snubber to limit high voltage spikes when the current is switched off.

A precharge resistor or similar circuit is usually needed when switching the CONTACTS, i.e. turning ON into a capacitive load.
1 - 2 of 2 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.