# Motor overload protection



## Gamit (Dec 30, 2009)

Am I correct when stating that every motor needs over load protection and using a breaker for OLP is a violation? Over 1HP of course


----------



## slickvic277 (Feb 5, 2009)

Gamit said:


> Am I correct when stating that every motor needs over load protection and using a breaker for OLP is a violation? Over 1HP of course



Breakers and fuses are used for short circuit and fault protection. Typically you'll see overload relays/"heaters" used for olp.


----------



## Wirenuting (Sep 12, 2010)

Gamit said:


> Am I correct when stating that every motor needs over load protection and using a breaker for OLP is a violation? Over 1HP of course


If the 1HP or less is auto start then it needs O/L protection.


----------



## Gamit (Dec 30, 2009)

Wirenuting said:


> If the 1HP or less is auto start then it needs O/L protection.


So answer is yes every motor that automatically starts needs OLP


----------



## brian john (Mar 11, 2007)

Gamit said:


> So answer is yes every motor that automatically starts needs OLP


Some motors have internal thermal protection.


----------



## Wirenuting (Sep 12, 2010)

Gamit said:


> So answer is yes every motor that automatically starts needs OLP


I like to install them even when not required when they are in normally unmanned spaces & connected to a device with a belt. Some "people" like to replace v-belts and tighten them down with a pry bar.


----------



## Wirenuting (Sep 12, 2010)

brian john said:


> SOme motors have internal thermal protection.


Yes your right about that.


----------



## captkirk (Nov 21, 2007)

Wirenuting said:


> Yes your right about that.


 is that you or your kid in the turret in your avatar.


----------



## Wirenuting (Sep 12, 2010)

captkirk said:


> is that you or your kid in the turret in your avatar.


My kids have kids older then that baby. 
It was a web find, but made me think of being a kid dreaming of what I wanted to be when I grew up. LoL

I would have put up a star trek pic, The city on the Edge of Forever.. But you would have called me on it Capt. 
And it was James R. Kirk before he changed his name to James T. Kirk, Were no man has gone before, was on the headstone.


----------



## BBQ (Nov 16, 2010)

EVERY motor needs overload protection of some type.

That can take many forms

Some small motors are impedance protected by design.

Some motors have internal overloads (Think smaller table saws or garbage disposers)

Some motors can be overload protected by breakers or fuses.

Some motors need motor overload devices

Some motor have internal temp probes that shut down the motor starter.


----------



## micromind (Aug 11, 2007)

The only motors that are not required to have overload protection are fire pump motors. They are not permitted to be protected.

As far as I know, every other motor has to have some sort of O/L.

Rob


----------



## wayne g (Nov 28, 2010)

All motors do need some form of protection, usually the larger the more protection. Like heater coils within a tenth of an amp so as not to burn up the motor. Expensive to replace much cheaper to protect.


----------



## kwired (Dec 20, 2009)

wayne g said:


> All motors do need some form of protection, usually the larger the more protection. Like heater coils within a tenth of an amp so as not to burn up the motor. Expensive to replace much cheaper to protect.


One tenth of an amp on a 100 amp rated motor is not a big deal.

One tenth of an amp on a 1 amp rated motor is. 

One tenth of an amp is not the issue, percent of rated current is.


----------

