Solenoid Material

[nlj]

Does anybody have experiences (good or bad) with a certain solenoid potting material? We are having issues with a nylon potting material melting and a polyurethane potting degrading. Other than potting compound are there any suggestions on waht may be causing the solenoid to reach such a high tempearture to fail? We have tried to replicate the failure and have not been successful.

Things that have been checked include wire varnish, potting material, installation.

Thank you!

 

[MikeHalloran]

If nylon is melting, you're lucky the polyurethane didn't catch fire.

You have to reduce the heat.

You can improve the cooling of the solenoid, e.g. by blowing cool air across it,
OR, better,
by using a better driver circuit, that supplies full current to the solenoid during pull-in, and reduces the current when the solenoid has moved to its seat, during hold-in.

Speaking of the solenoid seat, be sure that the solenoid is not mechanically held off from being fully seated when energized; that will really mess them up.



Mike Halloran
Pembroke Pines, FL, USA

 

[itsmoked]

Mike's made some really good points above.

Is your solenoid AC or DC powered?
What job is it doing?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[nlj]

Thanks for the information. I will look into those things.

It is DC and is part of a hydraulic system; controlling flow to a variety of hydraulic equipment.

 

[itsmoked]

Is it being heated additionally by the hydraulic fluid?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[ScottyUK]

Look at a compound with improved thermal conductivity. Dow used to make a high thermal conductivity pourable compound, no idea what its number was because it was quite a few employers ago. Most of the major epoxy manufacturers have thermally-conductive options too but they're a nightmare if you need to rework anything.

 

[ScottyUK]

You can edit and delete them now you know... right hand side of the screen.

 

[zeusfaber]

Thanks for pointing that out Scotty - hadn't noticed. Both posts now deleted.

A.

 

[ScottyUK]

Re-reading the original post, is the supply voltage correct? Running at 28V instead of 24V increases power dissipation by 34%, a situation which is fairly common on mobile plant with a battery and alternator. That could easily get you in trouble.