Electrical Troubleshooting
       Compressors Forum


Electrical troubleshooting air compressors is a bit complex.

For decades now I have been helping folks size their air compressors, guiding the installation of compressed air plumbing, help them understand SCFM and how their air system works, and through this website, get tons of requests for information on electrical troubleshooting air compressors.

No, I am not an electrician. I understand how compressors work, and the interface between electrical power supply, the pressure switch and the electric compressor motor.

Therefore, where possible, I will be happy to provide information about my experiences with the electrical troubleshooting of air compressors, but mostly, I hope that you, with your much greater experience in the electrical side of things, will contribute to help those folks in need of some air compressor guidance.

If you have a compressor electrical problem you would like help with, please use the form. If you can offer advice to those seeking information, even if that advice is that it is time to take your air compressor motor to the shop, or some such, then please, click on the comments below and add your advice for those folks that have already posted.

We all thank you.

Bill

Electrical troubleshooting of compressors.

Got a compressor electrical problem? Or better yet, have some advice on compressor electrical issues? Please let us hear about it.

What your question / advice is about:

What Other Visitors Have Said

Please scroll to the bottom to see questions and advice on electrical-troubleshooting-compressors from other visitors.

Airbrush Compressor Wiring...need to rewire capacitor. Help!  I have a Central Pneumatics 92403 Oilless Compressor for my airbrush setup. It was given to me with a bad capacitor. I have purchased the new capacitor,...

overload trips once evry morning before we open.  We had a 3phase 208v compressor that the tank developed a leak. We replaced it with a smaller single phase 208v unit.

The compressor runs great all ...

Wire size  What wire size should I use for 5 hp at 42 feet away

______________________
Bill says...

Good question, and one everyone should ask when they are ...

How do you test the capacitors? And how do you safely discharge them?  I have a Porter Cable oil free compressor (mdl#CPF-6020-1) that pops my dedicated 20 amp 110v breaker as soon as you turn it on. The motor turns over ...

Compressor keeps cutting off before desired set pressure is reached.  Air compressor cuts off , tryed by-passing pressure switch and main switch, compressor would run only about a minute, then cut off, could this be a capacitor ...

3ph 5hp motor and control box, change to single ph??  I have a Speedaire model 1WD55, SKU-35812 2 stage, 5 hp motor-3ph voltage rating 208/230/460, current rating-14/13.8/6.9 . Can the the motor be changed ...

Air compressor has no power to breaker or capacitor.  I just took my Emglo in for repair because it has having a terrible time starting.

They replaced the capacitor, with what looks like a used one, and ...

why dose the compressor not kick on unless i press the reset button  after each cycle the pressure drops to the point where it should kick on but it will not unless i press the reset button. the motor is a 5 hp , compressor ...

hi what gauge wire and breaker amp should i use for my air compressor?  Ingersoll Rand Electric Stationary Air Compressor — 5 HP, 18.1 CFM @ 90 PSI, 230 Volt, Model# SS5L5

running 20 feet from breaker to air compressor

_________________________
...

Compressor keeps burning up contacts on pressure switch  I have an Ingersoll Rand SS3660V 60Gal 3 HP compressor. About a year ago I replaced the pressure switch because the contacts on the switch were burnt and ...

putting pressure switch back together  i have a sears air compressor and took pressure switch off due to breaking pipe thats attached to switch.well i took (4)screws off that hold it and the ...

Compressor cut out  I have a 84ish model Devilbiss single phase 5hp.
Cut in pressure @ 120psi, cut out @ 160.
I was using the air to blow out some dust for another tool....

Stress relief line.  Do I need to reinstall the stress relief line on my compressor? I changed the pressure switch and the hook-up is not the same. It is a reciprocating compressor,...

Ingersoll Rand type 30 t30 Electric motor  I have a t30 that had a 5hp 3 phase electric motor. The motor was removed and I am going to replace it with a single phase. The compressor motor is a 2475 ...

New capacitor blows after 10sec   Folling a post about a part I was looking for I found out that its called a capacitor. After finding 1 which was'nt an easy job due to where I am located,...

Ingersol rand T30 5 hp. 80 gal. tank  It will start up and run for a few minutes and then it will slow down and speed back up about 4 or 5 times then trip the breaker thats with the valve on ...

My compressor fills up fine but when it goes to refill ...  My compressor fills up fine but when it goes to refill its self the motor turns on then turns off. I let it sit for a little while then it works.

___________________________________
...

How do i fix the air compressor from blowing fuses when starting?  Compressor has work fine for 15 year.

Now when you try starting it, it blows fuse.

I've checked the check valve and it works.

I've even bypassed ...

shop compressor wiring 230v  Its a 5hp 230v atlas compressor, it has only 2 wires coming from motor to the air pressure switch..( im assumming they are both my hots) my question is ...

Air Compressor Wattage Requirement  How large a generator (portable) do I need to adequately power a 230V/20Amp Air Compressor, Single Stage, V Head 3hp?

air compressor cut in randomly - changed the pressure switch  I have a air compressor which i changed the pressure swith because it was recycling on and off .

It now gets the pressure up to the switch out pressure ...

Just replaced brushes and put it back together - Running Problems  I have a CFBN 125A-3 I just replaced brushes and put it back together and it stutter runs.

I mean it runs and turns off over and over as though someone ...

Blows breakers...  Can a pressure switch cause a breaker to blow? I think capacitors are good. Motor with compressor turn freely by hand.

Rich

______________________
...

how do i convert an ajax air compressor 110 to 220 model-nm145tbdr030ad  how to re wire compressor from 110 to 220

_________________
Bill says...

You can only do this, Andrew, if the motor itself is wound for 120 & 240 ...

wiring in a c7501 60 gal Porter Cable compressor  I have installed a new compressor and have run 220 power to it and there is power at the pressure switch, but it won't fire up when I turn on the switch ...

My compressor shorts out when I try to start it  Hand Carry Twin Stack Air compressor
Model DD2T2
12 Direct Driv e Motor
Uses Household Power

______________________
Bill says...

Hi Dorothy. When ...

using GFCI outlet  When I plug in my sears 1hp, 2gallon compressor into the GFCI in the garage it will sometimes not turn the motor over to start running. It just Chugs, I ...

What is a typical electrical circuit for a large compressor load application and what are the issues  large compressor loads.

what are the elactrical aspects of starting in relation to power supply and detailed circuitry.

_______________________

Any ...

I am hooking up a new air compressor. 5 hp and 10 feet from the breaker box. what size wire and breaker should I get?  I have a new air compressor. It is 5 hp and 10 feet from the breaker box. I will use 220.I need to know the size of breaker to buy and what guage of wire....

electric motor on my compressor turns slow an trips the breaker was working fine the last time I used it.   33 gal. 11.9cfm. craftmans. A.O.smith motor. 115V rpm3450 mod. 919.167340. motor turns slow then trips breaker work fine last time it was used. how many ...

my air compressor quit working - all it does is hum now  i have a 240 v air compressor and it just quit working all i tdoes is hum now. Did the starting capicitors go bad? how do you test them?

__________________
...

HOW TO REPLACE THE 120 VOLT MOTOR TO 220 VOLT 50 HZ  WE HAVE COMPRESSOR SPEED AIR 4B222 CAN WE CHANGE THE MOTOR OF 120 VOLT TO 220 VOLT WHICH IS THAT MOTOR
_________________
Bill says...

Agnelo, as long ...

SPEEDAIRE DAYTON HP5 - WHERE DOSE THE YELLOW WIRE  IT TRY TO START BUT I NEED TO KNOW WHERE DOSE THE YELLOW WIRE AND THE WHITE WIRE GOS

_________________
Bill says...

Hard to answer this one, Ellis,...

Pressure Switch - Can I run two legs of my 3 ph power  Hi Bill,
You helped me with my check valve question and I am hoping that you can help me with my pressure switch question.

I forgot to order a Mag ...

CONNECT 2 COMPRESSORS TO ALTERNATE  How do you hook up 2 air compressors to the same output pipe and have them alternate between usage using a standard alternating motor switch. Czn we use ...

3 hp 20 gallon 230 volt Sears compressor won't start  My compreesor will not run. I've checked both hot lines and there is power. I've checked the pressure swith and even bypassed it. Nothing. The contacts ...

single ph,230v, 5hp, motor - capacitors and resistors are connected  How capacitors and resistors are connected to the this type of motor ????

________________________
Bill says...

Any electricians out there want ...

Wiring in a 6- gal 240 volt compressor  I am having trouble figuring out how to connect the 320 volt cable to the compressor switch. Two connections are labeled line so I assume that I connect ...

hitachi - stumpped with 3 wires 2 black & 1 white   I have a hitachi EC12 and had to repair it, I'm stumpped with 3 wires 2 black & 1 white I think the 2 blacks go to the overload switch, but where does ...

CHAMPION PNUEMATIC MODEL# OE4080 S/N# 70346  I need help with this project I have a 250 GALLON AIR TANK WITH A GENERAL ELECRTIC 2 HP CAPACITOR S/N# 5KCS224XB1OA 60CYCLES SINGLE PHASE 115/...

electric speedswitchwired wrong  someone pulled cord out of motor wires came off i need to see motor terminal block schematic

_________________________
Bill says...

Dan, the assumption ...

how does air cmpressor, transformer motor works?  just the basic principle of operation.

__________________________
Bill says...

In general terms, your electric compressor motor will pull too much ...

IR 10T-T30 15TM Air Compressor Rotation Direction?  We bought an IR 10T-T30 15TM Air Compressor. It is 3 phase and we don't know which way the compressor should rotate or does it matter?
Thanks,
Bim Rowley
...

what is the starting amp's of an 8 gallon 1.5 horsepower electric compressor motor?  I would like to use a portable generator to power the compressor. The generator is capable of producing 400 amps for start up power.

___________________
...

Air compressor (emerson) converted from 220 to 110?  It does not work now. I think it si simple wiring.

_______________________
Bill says....

I'm not quite sure where the question is, here?

Converting ...

I WANT TO KNOW HOW TO CONVERT A THREE PHASE DOWN TO 240  DONT HAVE 440 POWER ONLY 240 SNEED TO CONVERT THIS MOTOR TO 240 ITS GOT LOW AN HIGH AN IDONTKNOW HOW TO WIRE IT OR THE PRESSURE SWITCH

____________________
...

power - in our place there is a lot of power problem  hello,
iam having a SUGUNA 5HP air compressor 3HP motor,250 tank capacity, in our place there is a lot of power problem,3 phase current is not supplying ...

220v 2.2kw capacitor start, capacitor run motor, runs slow and overheats  Got this motor to run a hydraulic press. Even when not connected to press the following happens:
Motor starts up really slow, the cable (16 amp) starts ...

Fuse blows on shut down  Last week a couple days when turning off a three phase 480v compressor one of the fuses blew. Today when turning on one of the fuses blew in half. What ...

Snap-on tools model AC10120H  Snap-on tools model AC10120H

Hello,

We bought this unit at an auction and it is equipped with a Baldor electric motor. It came from the US army.
It ...

Do I have to small of a battery supply, or is my compressor to powerful to have a toggle switch in the power line?   While my pump is filling the tank, the toggle switch in my main power line heats up, then after a few days (2or 3), it tends to melt, or burns up. I ...

Sanborn ~ How to wire a 30 amp 2 pole 110\120 v contactor coil to a pressure switch.  This is a sanborn 80 gal 220/5 hp motor.

What I am trying to figure out is the why the 110 v side of the pressure switch to the magnentic pick up 110 ...

It cut off right after I turn it on  I think that there is electrical short somewhere with my compressors because it cuts off right after I turn it on and it shuts down the electricy of the ...

Motor quits..starts humming.  After pressure builds up the motor starts humming and will not build anymore pressure. When pressure is taken off and restarted it will build pressure....

have a saylor/beale when turned on all it's does is hum?  when it's turnd on all it does is hum.

______________________
Bill says....

Billy, when it hums, is it a tune you recognize??

Kidding aside,...

THERMAL RESET SWITCH  I HAVE A 5 HP SINGLE PHASE 230V COMPRESSOR THAT THE THERMAL SWITCH KEEPS CUTTING OFF. IT JUST STARTED DOING THIS TWO DAYS AGO IT HAS HAD BEEN WORKING FINE ...

my ingersol rand rotery screw2w compressor - wiring issue  I have a Ingersoll Rand up6-15c-125 air compressor with a 100-c60d01 allen bradly starter. A ingersol rand service repair man told me to replaced the .starter ...

How bad did i hurt my air compressor, its not running now.  I ran my compressor off an extenion cord were it kept tripping breaker then it started to run slow then hum then stop. I rented another one it too did ...

pressure switch on a compressor - how to wire from 120 to 240  have a compressor that i cutover from 120 to 240 but don't know how to wire the existing pressure switch

_________________
Bill says....

Chuck, lots ...

on the 3 HP, 21 Gallon, 115 PSI Cast Iron Vertical Air Compressor what is the startup amperage draw?  I see that the running amperage is 7a, need to know what the draw at start up is. this is the Central Pnuematics one
Dave
daven0lva@gmail.com

sanborn 5hp 80 gallon  how to wire

_______________
Bill says...

Hi there. How to wire what? The 220 volt line to the receptacle?

Please add a bit more info about what ...

thermal cut out, reason, if reset how long last the same compressor?  Found a reciprocrating compressor in thermal cut out due by lack of refrigerant, copressor body overheated, ohmed out C-S= OL, C-R:= OL, S-R 5.4 MOHMS,...

how to connect the circuit reset button up?  I have a dual voltage Puma compressor and changed it from 115V to 220V how does the circuit reset connect?

_____________________

Bill says...

Jeff,...

worthington air compressor horsepower requirements  I have a worthington air compressor with a 8 1/2" x 3 1/2" x 4" stroke cylinders. What would the horsepower requirement be to 150# pressure?

__________________
...

Compressor won't start - makes hummimh sound  Hi, I wonder if you can help please. I have a Rondy RDY100CA50 compressor. I was using it okay and then it stopped as normal when the tank was full of ...

compressor taking high current as compared other two similar compressors  M/S Khosla-crepella compressors;Model no:2HB2BIST;reciprocating,twin cylinder,double acting,nonlub,watercooled compressor;capacity 1667NM3/hr at 8.33kg/...

HOW DOES STARTER WORK 0N 2PHASE  A-B CONPRESSAR

______________________________
Bill says...

Danny, consider a starter as a fast-discharge battery.

Depending on the motor's ...

Electrical ` trying to hook the compressor to a generator  Im trying to hook the compressor to a generator, not sure how the wiring goes on the plug side or the switch side. Can you show me?

________________________
...

devilbiss  Bought, a used Devilbiss 60 gl 6.5 hp oilless air compressor.

Hooked up a standard 3 prong dryer cord to the compressor, and installed the matching ...

Older Speedway air compressor  Need info on wire connections. Does anyone have a diagram or photo of the exterior wire connections?

_________________

Are you sure you don't mean ...

3 phase 208v 10hp pressure switch question  trying to hook up a 10 hp 3phase compressor for a friend. he bought this at an auction and i think hes missing something.

im an electrician but never ...

My compressed motor is running slow (speed changes)  my compressed motor is running slower than normal and slows and speeds up a lot.

I checked the power and I have 15 amps going the regulator but the ...

Red/White/Green wires.. to a 3-pronged dryer outlet.. How?  A while back, I got a horizontal 33gallon 220V Craftsman air compressor from a friend for a great price. Only problem was that his ex-wife cut the plug ...

How to wire a 5hp 220v motor  About a 40 year old Quincy two stage. Previous owner said it ran fine. Should be a capacitor start, capacitor run motor (written on a cover plate.) Please,...

Why the machine shutdown in few seconds when high stage temperature sensor reads high temperature?  our machine shutdown in 20 seconds because one of the sensor in compressor side reads high temperature where by cause the machine to shutdown.

If you ...

ADVICE  MY 5HP. SINGLE PHASE 220 AIR COMPRESSOR SHUTS OFF AFTER A FEW MINUTES.THE RESSET BUTTON KICKS OUT LET COOL DOWN BUT SAME THANG HAPPENS.DID NOT SMELL ANYTHANG....

Fan direction  Which direction should the fan rotate when looking at it? I had to rewire the motor and I think the cpm[ressor is rotating the wrong direction. I think ...

Need to wire a 220 v Charge Air Pro Compressor  I need a wiring diagram for the pressure switch

________________________
Bill says...

Dennis, if you aren't 100% sure of what you are doing, maybe ...

Wont turn off with how i wired contactor  3 phase 7.5 hp

__________________
Bill says...

Hi J. Galaz. Unfortunately, I cannot fix your wiring issue through a website, and I make a point ...

AIR COMPRESSOR shuts off every 10 minutes...  After about 10 minutes of running it shuts down, then I have to wait about 15 minutes before it'll turn back on, any help would be appreciated, thanks
...

Air compressor motor stops  after I push the reset (red) button, the compressor will run for about 5 seconds and then cut off. The air tank is not full at all of air.

______________
...

compressor starts but humms  When I plug in my compressor sometimes it starts other times it makes a humming noise and then the circuit breaker goes.

__________________
Bill ...

why do I have to keep hitting the reset button on the starter  Every few cycles i have to reset the mag starter.
The hotter it is outside the more it happens.

____________________
Bill says...

Jeff, it ...

how much a 135hp 90psi compressor take watts to power it  i have this s10 low rider that i want to hook a compressor to a tank i have juss wondering how much watts or enery or power it take to power that kind ...

My home a/c unit keeps blowing fuses at random intervals  I have a Carrier 8000. The unit is probably about 10 years old. When I replace the 3 amp fuse and allow the fan to run, it is okay. However, when the ...

When i plug in my compressor it wont turn the pump with out help?  if i help the motor to go it will turn but otherwise nothing

______________________________
Bill says...

Hi Ken.

First check and see what ...

AIR COMPRESSURE  HOW MANY AMPS DOES IT TAKE TO RUN A 6.25 HP 28 GAL. AIR COMPRESSURE 110 V.

______________________
Bill says...

Hello, whoever you are. I don'...

Motor won't start with high pressure  When low pressure in tank unit starts right up. When there is pressure in the tank and it's topping off the pressure, electric motot jumps back and forth ...

High air temp light on my Quincy QT-5  Lately, my high air temp light is not allowing the compressor to run. I have a separate electrical panel box that this light is on, with start and stop ...

Compresser hums when it should build up pressure.  when some air is used the air compresser hums instead of pumping more pressure

______________
Bill says....

Carlton; your compressor hums? Do ...

Air compressor won't start  My Ingersoll Rand 5hp230V single phase two stage compressor won't start. Has been in production for 5 1/2 years with no problems. Came into shop and found ...

Motor dieing  My kobalt compressor motor starts as strong as usual then after 20 seconds dies to a stop. Been using the compressor on the same outlet for 2 years..new ...

plug compressor in and hit start and it hums very little and stops and i have to reset it  Plug compressor in and hit start and it hums very little and stops and i have to reset it
king craft 6 gallon 3.5 horse.

__________________
Bill ...

Compressor motor issues  I have a compressor with a capacitor strat single phase elactric motor the name plate is long gone but it might be 1 1/2 or 2 HP. When I plug it in, the ...

Thermal cutout switch?????  I have a I.R. 5H.P. 80 gal tank and the thermal cutout switch on the motor keeps setting after four or five cycles of the compressor coming on and off....

My compressor melted one side off the plug end when i pluged it up  I pluged up my aircompressor and one side off the plug melted.

____________________________
Bill says...

Yikes!!! That's not good.

Sounds like ...

Compressor trips the on- compressor circuit breaker  Hello,

I have a 2HP Puma Air compressor Model A002. The original circuit breaker body was cracked so I had it replaced with a similar one, 10-16 Amps....

Wiring 5 hp compressor pressure switch  motor has black, white and ground. If using my clothes drier receptacle would i use black, red, white and ground. Does the other 2 contacts of the pressur ...

Fatal error with extension cord?  I used my son-in-laws small air compressor with a very long extension cord to fill a backyard blow up ring pool. It worked but air leaked out and when ...

The compressor motor starts to cut in and out and feels hot .  I HAVE A Ingersoll Rand 5 hp 80 gallon two cylinder compressor 230 volt .

I just replaced the pressure switch since the motor started to engauge and ...

I HAVE TO CHANGE FROM 230 TO 460 VOLTS  THERE ARE WIRES ON MY COMPESSER THAT ARE MARKED INSULATE AND THEY ARE WIRED INTO THE LINE WIRE 1,2 AND 3

I HAVE TO CHANGE FROM 230 WHICH IS FACTORY ...

Compressor does not off when switched off.  Compressor keeps running when switched off. I think its an electrical faulth but does not know exactly what.
martnegrison2@yahoo.com

__________________________
...

Compressor dies after running for about 20 seconds needle acts like the switch got shut off and then restes after about 20 or so seconds  The compressor starts fine and runs for around 20 to 30 seconds and acts like someone shut the key off because the volt gauge goes to zero and resets istelf ...

craftsman 919152920 220v wiring  I have craftsman air compressor model and I would like to wire it to 220v. where I can find the instructions?

David

_____________________
Bill ...

What is the voltage?  what is the voltage on a vane compressor

___________________
Bill says...

No idea. It would be nice to know the make, the HP etc., and maybe then ...

AIR COMPRESSOR WIRING 110 or 220?  If I have a air compressor that gives me the option to wire it either 220 or 110 volt what is the difference , which is best.



Bill says...

If ...

Power demand of air compressor.  what is the approximate power requirement for a screw compressor compressing 15 Nm3/min of air at 8 kg/cm2(g) pressure?

screw compressor rating for ...

Voltage converter,step down and up. 220v to 110v.  voltage converter,step down and up. 220v to 110v.



Bill wonders...

Hi Rich:

First off, my apologies for the lateness of the response. I'...

wiring up motor leads  I have a speedaire 5hp 3 phase counterclockwise 52045B2 motor on a speedaire need to know how to wire correctly. Thank you, Courtney McManus, Missouri ...