Recommend Electric Motor Protection: Fuses vs PTCs?

[KenO]

Now have a few fuse blown AC electric motors and am trying to decide if should use a std fuse or a resettable fuse.

Have been trying to research this and recently found "Fuses vs PTCs..."
Was interested in "Motor overcurrents can produce excessive heat that may damage the winding insulation and for small motors may even cause a failure of the very small diameter wire windings. The PTC will generally not trip under normal start up currents. Motors are commonly protected by radial leaded PTCs."
http://www.jdtfuse.com/support/support318_en.html

Am interested in any comments concerning Electric Motor Protection.

Thanks

Ken

 

[Cydrome Leader]

KenO <kenitholson@yahoo.com> wrote:

Now have a few fuse blown AC electric motors and am trying to decide if should use a std fuse or a resettable fuse.

Have been trying to research this and recently found "Fuses vs PTCs..."
Was interested in "Motor overcurrents can produce excessive heat that may damage the winding insulation and for small motors may even cause a failure of the very small diameter wire windings. The PTC will generally not trip under normal start up currents. Motors are commonly protected by radial leaded PTCs."
http://www.jdtfuse.com/support/support318_en.html

Am interested in any comments concerning Electric Motor Protection.

what size of motors are you dealing with here? Are they stopping and
starting alot?

Did they work before and the blown fuse problem is new?

Recurring overcurrent protection device trips are an indication of
something being wrong.

 

[KenO]

Hi Cydrome Leader,

Will try to answer all your questions.

"what size of motors are you dealing with here?" They are from Chinese 16" Oscillating Stand Fans similar to http://www.target.com/p/lasko-3-speed-16-oscillating-stand-fan-black/-/A-11189973#prodSlot=medium_1_8

"Are they stopping and starting alot?" I inherited these fans as a "Learning Project" so do not know how they were used. From cleaning these fans do know that lint and dust built up over time so inadequate cooling due to blocked airflow may have been the major cause for blown fuse.

"Did they work before and the blown fuse problem is new?" Correct, only happened recently.

"Recurring overcurrent protection device trips are an indication of something being wrong." These fans only had std fuses so they were 1 time situations that caused blown motors.

Am wondering if Resettable Fuses instead of 1 time fuses would work for these fan motors so am interested in comments from anyone who has tried this.

Ken

 

[Cydrome Leader]

KenO <kenitholson@yahoo.com> wrote:

Hi Cydrome Leader,

Will try to answer all your questions.

"what size of motors are you dealing with here?" They are from Chinese 16" Oscillating Stand Fans similar to http://www.target.com/p/lasko-3-speed-16-oscillating-stand-fan-black/-/A-11189973#prodSlot=medium_1_8

"Are they stopping and starting alot?" I inherited these fans as a "Learning Project" so do not know how they were used. From cleaning these fans do know that lint and dust built up over time so inadequate cooling due to blocked airflow may have been the major cause for blown fuse.

"Did they work before and the blown fuse problem is new?" Correct, only happened recently.

"Recurring overcurrent protection device trips are an indication of something being wrong." These fans only had std fuses so they were 1 time situations that caused blown motors.

Am wondering if Resettable Fuses instead of 1 time fuses would work for these fan motors so am interested in comments from anyone who has tried this.

Ken

Ok, so it sounds like it's a small fan motor that now has, but didn't have
problems. You've cleaned out dust from the motors. Have you lubricated the
bearings?

The oil in fans like these gums up over time and the motors have to run
much harder. This may be the reason they keep blowing fuses. My general
rule is if the fan when switched off doesn't spin freely for at least
several seconds, it's time for re-oiling. Same things applies if there's
any hesistation in starting up. They should be upto speed in less than a
second.

 

[John Robertson]

On 08/23/2014 12:16 PM, Cydrome Leader wrote:

KenO <kenitholson@yahoo.com> wrote:
Hi Cydrome Leader,

Will try to answer all your questions.

"what size of motors are you dealing with here?" They are from Chinese 16" Oscillating Stand Fans similar to http://www.target.com/p/lasko-3-speed-16-oscillating-stand-fan-black/-/A-11189973#prodSlot=medium_1_8

"Are they stopping and starting alot?" I inherited these fans as a "Learning Project" so do not know how they were used. From cleaning these fans do know that lint and dust built up over time so inadequate cooling due to blocked airflow may have been the major cause for blown fuse.

"Did they work before and the blown fuse problem is new?" Correct, only happened recently.

"Recurring overcurrent protection device trips are an indication of something being wrong." These fans only had std fuses so they were 1 time situations that caused blown motors.

Am wondering if Resettable Fuses instead of 1 time fuses would work for these fan motors so am interested in comments from anyone who has tried this.

Ken

Ok, so it sounds like it's a small fan motor that now has, but didn't have
problems. You've cleaned out dust from the motors. Have you lubricated the
bearings?

The oil in fans like these gums up over time and the motors have to run
much harder. This may be the reason they keep blowing fuses. My general
rule is if the fan when switched off doesn't spin freely for at least
several seconds, it's time for re-oiling. Same things applies if there's
any hesistation in starting up. They should be upto speed in less than a
second.

Are you using slow-blow fuses? Didn't say...

John ;-#)#


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