Older Square D Mag Starter Question

[roblouvasz]

I'm using an older Square D magnetic starter on my 5 hp IR compressor. Originally the compressor didn't have a mag starter, but after burning out the start up windings on the original motor and replacing the motor with one from Grainger, someone recomended a mag starter. The one I'm using is a size 2 type D or T. I did replace the contacts and everything has been working fine. I also purchased a used coil for the starter just for a backup which I've installed to test and it works fine also. So here's my question, The coil part number is S1707 S1 T23A, 60HZ 208-220V, I've found a couple on Ebay that are L1707 S1 T23A, 60HZ 208-220V. Can anyone tell me what the difference between the "S" and the "L" at the beginning of the coil's part number? Will the "L" work also?

 

[alfredeneuman]

"Someone" suggested a mag starter, which has no effect on a start windings failure.
It's merely a switch that controls the motor, and nothing more.
Someone is misinformed.

 

[roblouvasz]

Maybe I should have been more specific. The original motor burned up because all of the start-up/running current was being passed through the contact points of the pressure switch. After a time, the contacts had become damaged due to the current and caused the motor to fail. That's why I decided on the mag starter.

 

[wyliesdiesels]

Maybe I should have been more specific. The original motor burned up because all of the start-up/running current was being passed through the contact points of the pressure switch. After a time, the contacts had become damaged due to the current and caused the motor to fail. That's why I decided on the mag starter.

I think u missed the point Alfred made. Using a pressure switch or motor starter has NO effect on the windings in the motor. However, using the wrong size pressure switch or starter will cause the switch or starter to die prematurely. But not the motor!

Something else killed the windings in your motor!

As far as the contacts going bad in the pressure switch, you probably had the wrong size pressure switch and contacts, which is why they(the contacts) died/burned out!

But FYI, the starter ALSO has contactors just like a pressure switch, that the motor current runs through, so u really didnt change anything. And just out of curiosity, are u now using the a pressure switch to open and close the coil in your starter?

 

[1500hd]

But FYI, the starter ALSO has contactors just like a pressure switch, that the motor current runs through, so u really didnt change anything. And just out of curiosity, are u now using the a pressure switch to open and close the coil in your starter?[/QUOTE]

"Someone" suggested a mag starter, which has no effect on a start windings failure.
It's merely a switch that controls the motor, and nothing more.
Someone is misinformed.

Not really true, a starter has thermal units to protect the motor from drawing too much current. So maybe the motor was drawing high amps and "someone" was trying to help by suggesting a starter.

 

[G_P]

Did the original motor have thermal protection? Does the new motor have it?

If the old motor had no thermal protection it could have overheated and burnt up the winding. Mag starters will provide protection as long as you put in the correct heaters sized to your motors specs.