Magnetic starters

[bronc3buster842001]

Looking at magnetic starters for my air compressor.... The motor I will be running is this one...

http://www.baldor.com/products/spec...=1400-1800&winding=37WGW885&rating=40CMB-CONT

So how do you chose a mag starter... Heres 2 I was looking at.... Do you match the amps or does the mag starter need to be set a little higher

http://www.ebay.com/itm/NEW-5-HP-SI...974?pt=LH_DefaultDomain_0&hash=item4157685a9e

http://www.ebay.com/itm/NEW-7-5-HP-...310?pt=LH_DefaultDomain_0&hash=item41576863be

 

[930dreamer]

The mag starter needs to be rated for the starting motor.

 

[#1SomeGuy]

Well since the motor says 7.5 hp, I'd go with the 7.5 hp mag starter.

 

[bronc3buster842001]

Thanks guys... Looks like Ill go with the one in the second link.....

Anyone have any feed back on them or is their a better one for around the same price

 

[rockwithjason]

they only get more expensive. that looks to be a no name product.

 

[Norcal]

they only get more expensive. that looks to be a no name product.

No name ChiCom junk, doubt it is UL or any other NRTL listed. The OP would be better off w/ NEMA style starter made by Siemens (formerly Furnas), Allen-Bradley, or Square D.

 

[ffast65]

resurrecting this old thread, Bought an champion with a Siemans 16BF35BGASY starter that was used on a 7.5 HP 3 Ph motor that pulled 21.7 amps at 208.

Going to buy a L1510T which will pull 31 amps. Can this same motor started be used? The siemans site says its rated for 30 amps at 203/240 v.

If not, can it be converted?

 

[Norcal]

resurrecting this old thread, Bought an champion with a Siemans 16BF35BGASY starter that was used on a 7.5 HP 3 Ph motor that pulled 21.7 amps at 208.

Going to buy a L1510T which will pull 31 amps. Can this same motor started be used? The siemans site says its rated for 30 amps at 203/240 v.

If not, can it be converted?

Simple answer, no. A single phase motor will require a larger starter then the same size 3Ø motor & needs to be rated for that motor.

 

[ddawg16]

resurrecting this old thread, Bought an champion with a Siemans 16BF35BGASY starter that was used on a 7.5 HP 3 Ph motor that pulled 21.7 amps at 208.

Going to buy a L1510T which will pull 31 amps. Can this same motor started be used? The siemans site says its rated for 30 amps at 203/240 v.

If not, can it be converted?

Simple answer, no. A single phase motor will require a larger starter then the same size 3Ø motor & needs to be rated for that motor.

Norcal is correct. It's a common mistake a lot of guys make. I was doing a job recently where we were using an electrical contractor to do an install on 3 large systems...3ph motors from 5 HP up to 325 HP. Part of the install included installing local disconnects. They looked at the motor FLA and bought disconnects based on the rating.....they were not happy when I pointed out to them that they had to look at the HP rating for a given voltage...."See, right there on the label inside the door". They had to replace half of them.

I was a bit surprised to find to electricians with 20+ years experience each and they didn't know that little fact.

 

[ffast65]

NorCal and John

Thanks for the replies. As I haven't pulled the trigger on the motor, I could use some sizing advise.

Will this existing one cover a 5 hp 1phase 1740 motor?

If I used a 7.5 hp, do I need to jump to a 40 amp unit?
This is an area I don't have any work experience with motor starters. I'm assuming my existing can't be upgraded

 

[rockwithjason]

you need a nema size 3 starter for the 7.5hp motor

 

[wyliesdiesels]

NorCal and John

Thanks for the replies. As I haven't pulled the trigger on the motor, I could use some sizing advise.

Will this existing one cover a 5 hp 1phase 1740 motor?

If I used a 7.5 hp, do I need to jump to a 40 amp unit?
This is an area I don't have any work experience with motor starters. I'm assuming my existing can't be upgraded

Motor starters are mainly rated and sized based on HP NOT amps! This is because motors have in-rush starting currents! The in-rush current of a motor can be 3x-6x the FLA!!!