motor overloads

[JdoubleU]

I know when selecting the motor overloads you take the nameplate FLC and multiply it by 125% if the service factor of 1.15 or more. When selecting a range for electronic overloads how do you do that?

 

[weressl]

I know when selecting the motor overloads you take the nameplate FLC and multiply it by 125% if the service factor of 1.15 or more. When selecting a range for electronic overloads how do you do that?

The manufacturer provides instructions how to select the overload.

Some ranges are generated by IEC standards and some tries to follow the NEMA starter sizes to cover the corresponding motor HP.

You dial the electronic overload to the FLA multiplied by the service factor. Should you have drastically different ambient temperature at the motor than the controller adjust accordingly.

 

[charlie tuna]

we always used nameplate full load amperage and increased it one size as listed on the motor starter cover..........

 

[JdoubleU]

we always used nameplate full load amperage and increased it one size as listed on the motor starter cover..........

My purchaseing agent keeps asking me for range on the motor overload and I don't know how to answer that question other than how to size the overload in the code. The FLA on the motor is 2.2 amps

 

[iwire]

My purchaseing agent keeps asking me for range on the motor overload and I don't know how to answer that question other than how to size the overload in the code. The FLA on the motor is 2.2 amps

Is your PA getting NEMA OLs

or IEC OLs.

IEC OLs do not use heaters, they are adjustable over a range of currents.

 

[EBFD6]

This is really a manufacturer specific question. What I mean is a lot of manufacturers now will tell you on their overload selection charts that if your motor has a service factor of 1.15 then just take the FLC off the nameplate and match up to the chart, they already have factored in the 1.25% increase. Some do not however, so you really need to figure out what manufacturer you are using and go from there. Read their literature.

 

[brian john]

Las:

The electronics OL's are affected by temperature?