Posted By: Wireless
Motor Starters - 06/12/05 06:55 AM
Im new to posting but have been reading all the forums for a while great stuff!
On to my question we are setting up some panning machines with 1hp motors they are on a 20amp branch circuit with a fused disconnect do I need a overload protection starter as well or just a magnetic contactor?
Your replies are appreciated
Posted By: Tom
Re: Motor Starters - 06/12/05 11:54 AM
If these motors are single phase, they may have built in overload protection, read the data plate.
If these are 3 phase motors, then it is unlikely that they will have overload protection & you will have to supply it.
Posted By: iwire
Re: Motor Starters - 06/12/05 12:04 PM
The NEC requires all motors to have some sort of overload protection.
That may well be already provided in the motor or it may not be, as Tom stated.
Take a look at 430.32(B) or 430.32(D) depending on if the motors are automatically started or not.
Posted By: gfretwell
Re: Motor Starters - 06/12/05 04:27 PM
IBM used a buttload of 3p motors in their equipment and they all had O/L protection in the motor but you do have to read it on the nameplate to believe it.
Posted By: macmikeman
Re: Motor Starters - 06/13/05 02:59 AM
Aren't those little clicks- on overload protectors that come on three phase AC compressors used for other purposes besides AC/ Reefer motors?
Don't forget about the possibility of an impedance protected motor or the fact that sometimes the Short Circuit and Ground Fault device can also serve as the overload device per 430.55
Posted By: jack1984
Re: Motor Starters - 09/02/05 03:14 AM
you should know that most starters and motors have a variety of ways to be wired what exact type is your starter and motor