Help with Compressor Pressure Switch

[tigercreek]

I need help selecting the correct pressure switch to replace the bad one on an air compressor.
I picked up an older compressor that had a failing pressure switch.
And the switch on the compressor is not factory and also not rated for the compressor - the reason for the failure.
9013FHG12M1X (max rating is for 3hp)
The compressor I need the replacement switch for has a single phase 5hp 230v 22amp motor, a single stage pump with a 60 gallon tank.
So, if one of y’all in the know could help me with getting the right switch on this thing I would appreciate it.

 

[OccupantRJ]

Does the compressor have a motor starter, or does the pressure switch alone control the motor?

 

[tigercreek]

The motor has a start capacitor and a run capacitor

 

[Citation]

At 22 amps you are probably better off getting a 5hp starter. In compressors typically under 5hp and some low cost 5hp models, the motor current is directly switched by the pressure switch. In better 5hp compressors and compressors over 5hp the pressure switch controls a kind of relay switch that both acts as an overload protection for the motor and as an electrical switch. At that point the pressure switch will be switching something much less than 1 A vs 20+ amps.

You will still need a pressure switch but at that point the type of switch is less important since it only has to control a small amount of switching current, not the full motor power.

This is a low cost starter that would probably work for you.
https://www.amazon.com/dp/B00Y4X7J44/?tag=atomicindus08-20

As for a controller switch, if the contacts can be cleaned you could probably keep using it with the starter. Again, the heavy motor current will no longer go through the switch so even so-so contacts can probably keep serving a long time.

 

[tigercreek]

At 22 amps you are probably better off getting a 5hp starter. In compressors typically under 5hp and some low cost 5hp models, the motor current is directly switched by the pressure switch. In better 5hp compressors and compressors over 5hp the pressure switch controls a kind of relay switch that both acts as an overload protection for the motor and as an electrical switch. At that point the pressure switch will be switching something much less than 1 A vs 20+ amps.

You will still need a pressure switch but at that point the type of switch is less important since it only has to control a small amount of switching current, not the full motor power.

This is a low cost starter that would probably work for you.
https://www.amazon.com/dp/B00Y4X7J44/?tag=atomicindus08-20

As for a controller switch, if the contacts can be cleaned you could probably keep using it with the starter. Again, the heavy motor current will no longer go through the switch so even so-so contacts can probably keep serving a long time.

Thank you. This is what I was looking for.
I assume that this is wired between the motor and the pressure switch?

 

[Citation]

Thank you. This is what I was looking for.
I assume that this is wired between the motor and the pressure switch?

Yes, the starter is connected to the pressure switch and the motor. This is generically how it's connected
https://2.bp.blogspot.com/-1vhlJhPv...r+Compressor+Motor+Starter+Wiring+Diagram.png

 

[tigercreek]

Just to be clear, I would wire the WEG starter switch you suggested to a Square D pressure switch like this?

Yes, the starter is connected to the pressure switch and the motor. This is generically how it's connected
https://2.bp.blogspot.com/-1vhlJhPv...r+Compressor+Motor+Starter+Wiring+Diagram.png

 

[Citation]

Just to be clear, I would wire the WEG starter switch you suggested to a Square D pressure switch like this?

Not exactly like that as what you are showing would use the pressure switch to short L1 and L2

But almost like that. I would have to look at the exact starter to say but the general idea is the motor power comes from the wall, goes into the starter then into the motor. The pressure switch is used to send power from the wall into a relay in the starter. So you are correct that the wall power, pressure switch and motor all connect at the starter.

 

[tigercreek]

Not to kick a dead horse but I'm sure there are or will be others with the same question.
I found a wiring diagram at WEGs site.
This seems to be the answer for allowing an external device control the initiation to switch.

Not exactly like that as what you are showing would use the pressure switch to short L1 and L2

But almost like that. I would have to look at the exact starter to say but the general idea is the motor power comes from the wall, goes into the starter then into the motor. The pressure switch is used to send power from the wall into a relay in the starter. So you are correct that the wall power, pressure switch and motor all connect at the starter.