Does my solenoid need a diode?

[GABuggy]

I have a CC DS 48v 2000 with a Navitas 400amp controller, Admiral A1 motor and SW200 solenoid. I've driven it without problems for more than a year. Now when clearing out my garage and finding the original solenoid I realized that I never installed a diode for the solenoid. The cart works fine, should I install it? if yes will the OEM one work or should I get a new one?

[scottyb]

Originally Posted by GABuggy

I have a CC DS 48v 2000 with a Navitas 400amp controller, Admiral A1 motor and SW200 solenoid. I've driven it without problems for more than a year. Now when clearing out my garage and finding the original solenoid I realized that I never installed a diode for the solenoid. The cart works fine, should I install it? if yes will the OEM one work or should I get a new one?

Short answer is yes. Install a suppression diode on the small posts.

[G16Steve]

Originally Posted by scottyb

Short answer is yes. Install a suppression diode on the small posts.

The longer answer is yes it will work without it but it is better for the life of the solenoid if you have it there. :)

[Volt_Ampere]

It's actually for the life of the transistors that control the solenoid. (In the controller) The solenoid could care less if there is a diode on it's coil.

[GABuggy]

Thank you for the advice! What would be the specs of the diode / where to buy it from?

[Volt_Ampere]

You can re-use the OEM one. (or get one from any cart dealer) I forget the specs. Probably a 3 amp at least 100V diode.

[scottyb]

3a 1000v works well for all applications.

[MacGyverr]

I just installed a 400 amp navitas controller, the instructions stated " remove pre-charge resistor from contactor and discard".

[MacGyverr]

It shows a diode for series motors and none on shunt.

[meimk]

Originally Posted by MacGyverr

I just installed a 400 amp navitas controller, the instructions stated " remove pre-charge resistor from contactor and discard".

The precharge resistor is a different part than the diode. The diode is across the small terminals and works as a one way "valve" of sorts. It reduces backfeed that could damage the controller. The precharge resistor is just that - a resistor across the big terminals. It keeps a smaller charge (a little less voltage, but very little amperage) to lessen the shock / spike when the solenoid does get engaged. It extends the life of bothe the solenoid and the controller.