Basic Insulation for Accessible Terminals

[fifty60]

A thermal cut-out needs to be accessed to reset an over temperature alarm. The thermal cut-out is not touch proof because it has bare power input terminals on both sides of the reset button. I have tried applying shrink tubing but the positioning of the terminals makes this difficult. The shrink tubing covers most of the terminal, but pulls back a little bit everytime to leave some of the terminal exposed. Is there anything else I can apply to the terminal other than shrink tubing?

 

[PetrosA]

Are these crimp-on terminals? Would shrouded ones work? Maybe a picture would help.

 

[fifty60]

It looks something like this. Ther terminals are almost exactly like this, and there is a red "reset" button directly in the center of the thermal cut out. The terminals straddle the reset button.

 

[petersonra]

View attachment 9992

It looks something like this. Ther terminals are almost exactly like this, and there is a red "reset" button directly in the center of the thermal cut out. The terminals straddle the reset button.

I think whoever resets it is going to have to wear gloves and other required PPE.

 

[PetrosA]

Is there a reason you can't use an automatic reset thermostat like this?:

http://asahikeiki.co.jp/english/thermostat/list/us622.html

 

[GoldDigger]

If it is an overtemp alarm, an automatic reset type may work, especially if the alarm panel or annunciator latches the fault.
But if it is an overtemp cutoff on equipment it may require a manual reset before restarting the equipment for safety.
The linked unit is described as a thermostat, as in routinely opening and closing for temp control, rather than an over temperature sensor which will not be activated under normal conditions.

Tapatalk!

 

[fifty60]

Exactly right, there needs to be operator intervention to clear the alarm. Having the operator exposed to the open terminals creates other problems. The shrink tubing covers the terminals, but it always pulls back and i can't cover the entire terminal.

 

[GoldDigger]

I suppose you could fabricate an insulating bracket over the whole thing with either a hole for the push button or a captive button extension.
Is the temp being sensed from the metal attachment on the far side or does it need open air flow to work?

Tapatalk!

 

[K8MHZ]

Is this more like what you have?

 

[K8MHZ]

What is the voltage across the terminals?

Is the alarm circuit on that cut out current limited?

 

[GoldDigger]

Other solution is to require that the power be turned off before attempting to reset the sensor. Power off as in disconnect, not just as in control switch off.

Tapatalk!

 

[SceneryDriver]

Use the thermal cutoff to control 24vdc power to a relay. Use that relay to control your line voltage load.


SceneryDriver

 

[K8MHZ]

Use the thermal cutoff to control 24vdc power to a relay. Use that relay to control your line voltage load.


SceneryDriver

So why the concern about the bare terminals if it's only 24 volts?

 

[SceneryDriver]

So why the concern about the bare terminals if it's only 24 volts?

I was under the assumption that the OP was concerned about a higher voltage; perhaps 120vac. That's why I suggested the use of an interposing relay with a 24vdc coil.


SceneryDriver

 

[pjholguin]

I don't believe the OP stated the voltage. I agree with Scenery...what is the thermal cutout rated for?

I was under the assumption that the OP was concerned about a higher voltage; perhaps 120vac. That's why I suggested the use of an interposing relay with a 24vdc coil.


SceneryDriver

 

[K8MHZ]

I don't believe the OP stated the voltage. I agree with Scenery...what is the thermal cutout rated for?

Not so much the rating but the application. Cut outs may be rated for 120 VAC and used on 24 VAC.