Solenoid Valve coil is HOT to touch?

TimD · Sep 21, 2009

Hi,

I have a bank of 24v solenoid valves. All of the coils get very warm, close to hot, to the touch (Asco Red Hat II, green coil enclosure) if energized for a few hours. I am using 20 gauge wire from the supply to the coils, but the wire does not get warm. The coils only use 200-300 milliamps of current each, so I assumed 20AWG stranded for 10 feet was fine.

Is this normal? I have a beefy power supply feeding the coils, 24v at 20A and these are the only loads on the supply at the moment other than three motor starter coils.

Hope it's not serious.

Thanks

geniusintraining · Sep 21, 2009

I would not worry about it... many coils run hot, I think it depends on the insulation and quality of the coil, Asco coils are good... they are DC? and you have DC not AC correct?

leitmotif · Sep 21, 2009

Well if you were energized for a couple hours you would get warm also.
Assuming you are using AC coils on AC or DC coil on DC and you are using proper voltage rated coil and your power supply voltage is not too high you should be OK.

What is the definition of HOT?
I varies with the person
GENERALLY
if you can touch it for one second it is about 160F. This is getting a little warm for a lot of coils and motors but is getting to the realm of lets think about this.

You can touch for 3 to 5 second no problem.

Dan Bentler

TimD · Sep 21, 2009

Thanks guys.

I'll leave them energized for a while today and keep an eye/finger on them!

They are DC by the way.

Tim

curlyandshemp · Sep 21, 2009

TimD said:
Hi,

I have a bank of 24v solenoid valves. All of the coils get very warm, close to hot, to the touch (Asco Red Hat II, green coil enclosure) if energized for a few hours. I am using 20 gauge wire from the supply to the coils, but the wire does not get warm. The coils only use 200-300 milliamps of current each, so I assumed 20AWG stranded for 10 feet was fine.

Is this normal? I have a beefy power supply feeding the coils, 24v at 20A and these are the only loads on the supply at the moment other than three motor starter coils.

Hope it's not serious.

Thanks

Asco Red Hats always get hot. The coils use the rest of the solenoid as a heat sink, so NEVER remove the coil under power as the coil will burn out.

Clay B. · Sep 21, 2009

Little trick.

curlyandshemp said:
Asco Red Hats always get hot. The coils use the rest of the solenoid as a heat sink, so NEVER remove the coil under power as the coil will burn out.

If you do need to remove the coil from the solenoid for any lenght of time and the coil is going to be entergized (think 3 am need to get machine to run). One trick I have used is putting a bolt down the center of the coil when it would normally sit on the valve. This will act as a heat sink and slug at the same time and prevent the coil from cooking itself. This will save you from having to unwire the coil which can be handy at times.

jvdcande · Sep 21, 2009

Is the coil constructed for a monostable valve or for a bistable valve? I don't know the Asco range of products, but some European manufacturers do deliver light duty coils for bistable valve and heavy duty coils for monostable valves. If you energize such a light duty coil for a long time it might eventually even burn out because these coils are only constructed for short time activation, let's say a duty cycle of about 10% max (as in max 1 sec on and then at least 9 seconds off).

Kind regards,

Roy Matson · Sep 21, 2009

Yes, they will get too hot to hold your hand on after an hour or so.
BTW Puting a bolt inside the coil will drop the current if it's on AC but will have no effect on DC
Roy

Solenoid Valve coil is HOT to touch?

TimD

Lifetime Supporting Member

geniusintraining

Lifetime Supporting Member + Moderator

leitmotif

Member

TimD

Lifetime Supporting Member

curlyandshemp

Lifetime Supporting Member

Clay B.

Lifetime Supporting Member

jvdcande

Member

Roy Matson

Member

Similar Topics