Help...Anyone now how this control box works

[jamurr65]

I finally got this compressor running (1960s Saylor beall 705) to make sure everything works before I rebuild and paint. Temp. power to the control box #10 wire on a 40 amp breaker. The compressor started and this thing is smooth running...it pump to about 100psi and the contacts in this control box arced. Did I do something wrong???Or is something just worn out??? I dont understand how this electrical in this control box works. Can someone explain Please. What do I need???

 

[RPH]

Did the arc occur at the contactor when the motor shut off?

 

[jamurr65]

No the arc occurred during running and it shut down from the arc

 

[jamurr65]

The contact area was black and burnt looking so it must have been doing this before I got it.

 

[OccupantRJ]

Likely time for new replaceable contact points or a new motor starter, whichever is less expensive. Look it up by the numbers on the starter enclosure. They are easy to change, so it will boil down to expense. Contacts for some older units can be expensive or obsolete. Post the numbers for more help. There may be both a size and bulletin number.

 

[NUTTSGT]

The arc you saw should have just been from the switch closing/opening once it reached it's appropriate air pressure.

 

[jamurr65]

No this was a big arc and the compressor wasn't up its psi to shut down yet.

 

[jamurr65]

RJ Where would the starter be located inside the motor??? because their is nothing on the outside of this motor nor has their ever been.

 

[OccupantRJ]

RJ Where would the starter be located inside the motor??? because their is nothing on the outside of this motor nor has their ever been.

The box you pictured IS the motor starter. It is electrically activated to slam shut on startup and provide power to the motor. When the pressure switch is satisfied, it tells the starter to release and shut the motor off.

 

[OccupantRJ]

Watch this.

 

[jamurr65]

Thanks RJ that video helped out a lot. Would RSP supply be a source for my parts?

 

[OccupantRJ]

Thanks RJ that video helped out a lot. Would RSP supply be a source for my parts?

Post the numbers and someone will help you for sure. I shop online heavily for any parts of any type I need to buy.

 

[RPH]

Ok, you’re on the right path.

 

[md21722]

Thanks RJ that video helped out a lot. Would RSP supply be a source for my parts?

Not sure about getting repair parts for your existing one starter, but this would be an example of a new 5 HP one for $119.95:

https://www.ebay.com/itm/SQUARE-D-M...rentrq:93c42b811670ac88e2cf82f7fff2c739|iid:1

There are diagrams and threads on this forum for wiring this exact starter up. A bunch of us have put these starters on our own compressors myself included.

 

[OccupantRJ]

Ok, you’re on the right path.

Teach a man to fish.....

 

[seber]

Filing down the burned points to make them smooth is often a permanent fix. It will depend on how badly they have been allowed to get.

 

[jamurr65]

Here is a couple pictures of the starter, The red tag is from the base near what I think is a coil, it shows 30 amp max load. Does that mean I shouldn't have had this on a 40 amp breaker?? The contacts are pretty fried. Theirs another number on the coil. Also a pic of the overload protection, no idea what the dial is for, seems to be set on 100 ???

 

[Slupie]

Here is a couple pictures of the starter, The red tag is from the base near what I think is a coil, it shows 30 amp max load. Does that mean I shouldn't have had this on a 40 amp breaker?? The contacts are pretty fried. Theirs another number on the coil. Also a pic of the overload protection, no idea what the dial is for, seems to be set on 100 ???

Here is some good info on GE Contactors and Overloads,
https://www.geindustrial.com/catalog/controlcatalog/01_CC.pdf

http://www.mag-trol.com/product-publications

Somewhere on your contactor it should say the model number and NEMA size. You have 208/220 VAC coil and GE CR124 overlaod. From the pictures I can't tell what NEMA size the contactor is and what size the overlaod heaters you have.

GE Overlaod heaters chart http://www.mag-trol.com/docs/tables/GE/ge-overload-relay-heater-table.pdf

You can buy a new motor contactor and overload from here https://www.automationdirect.com/ad...ols/iec_contactors_-z-_starters_-z-_overloads

You will need the motor voltage, amperage, HP and how it's used. Air compressor starter wiring is slightly different than push button start/stop on a table saw. If you are not sure give them a call and the'll help you make some choices.

It cost me $36 to buy a new one for my 1986 PM66 Table saw about 3 years ago.

 

[jamurr65]

Thank you...very helpful information here.

 

[OccupantRJ]

By the time you get through finding and paying for replacement contacts for this unit, you may be better off purchasing the starter in post #14. Contacts are likely to be $60+. If the starter is an obsolete model, more than that. I have had to change out older starters at work because of this. Trying to repair them was false economy.