# motor internal therm.switch



## John Valdes (May 17, 2007)

If you have a thermal, use it. Just wire it into the drive stop circuit. I have seen some use it for an indicator light, so the motor does not shut down. Is it a thermistor (RTD or Thermocouple) or NC thermal switch? If it is a sensor and not a true thermal shut off, you will need to program the drive as required.


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## randomkiller (Sep 28, 2007)

I would not bother with it provided the VFD is set up properly.


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## MDShunk (Jan 7, 2007)

randomkiller said:


> I would not bother with it provided the VFD is set up properly.


I agree. If the drive is setup properly and the motor overhears at some point, you might as well keep running it until it dies. The exception might be motors cooled with an external blower motor. Some plants wire them to a light for a "head's up" so they can do a planned shutdown.


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## KyleD (Apr 28, 2014)

*KyleD*

Any one of you fellas built a panel for a 1964 American ToolWorks hole wizard ? This has a heater coil on the top inside of panel which is wired to the starter for the spindle,(10 H.P. 3 phase), and tons of ancient but working contactors. Allen Bradley 705 TOD K etc, and I want to replace it all, not with 505s and 509s, etc, but rather with solid state, IEC vs NEMA. Any suggestions ?


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## wendon (Sep 27, 2010)

KyleD said:


> Any one of you fellas built a panel for a 1964 American ToolWorks hole wizard ? This has a heater coil on the top inside of panel which is wired to the starter for the spindle,(10 H.P. 3 phase), and tons of ancient but working contactors. Allen Bradley 705 TOD K etc, and I want to replace it all, not with 505s and 509s, etc, but rather with solid state, IEC vs NEMA. Any suggestions ?


I'd suggest you stick to one thread with your topic.:whistling2:


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## varmit (Apr 19, 2009)

In classified areas a thermal switch is required to shut down the motor if the motor temperature is near the ignition temperature of the hazardous atmosphere.


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## Southeast Power (Jan 18, 2009)

spec grade said:


> replacing existing motors in non classified area with vfd controlled xproof motors.Does code require internal therm.switch to be wired.vfd provides overcurrent protection.I did connect but i do not believe I had to.Any thoughts?


Ok, now you have to tell us how you ended up with explosion proof motors.
Surplus? Gift? T&M job?


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## eric7379 (Jan 5, 2010)

varmit said:


> In classified areas a thermal switch is required to shut down the motor if the motor temperature is near the ignition temperature of the hazardous atmosphere.





jrannis said:


> Ok, now you have to tell us how you ended up with explosion proof motors.
> Surplus? Gift? T&M job?


This thread is 4.5 years old. Hopefully he figured something out by now! :laughing:


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## JRaef (Mar 23, 2009)

eric7379 said:


> This thread is 4.5 years old. Hopefully he figured something out by now! :laughing:


Or not, and it blew up...

KyleD, this is why it's a bad idea to post in an old thread (called a "zombie thread" because it should stay dead). People read it because it shows up as if it were new, but needlessly respond to the old stuff instead of your new issue because they don't think to look at the old dating. New issue = new thread.


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## varmit (Apr 19, 2009)

Oops, I didn't look back at the dates far enough.


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