Had the same problem just yesterday on my compressor. The little spring loaded tabs on the pressure switch have to move freely in the off position. When in the off position you should be able to move the tabs around a bit. One of mine had become stuck and wasn't moving around freely and the lower contact on the tab was not making. Personally I think it's a design flaw with IR compressors. I am looking at replacing the switch with a different design.

FWIW do this with the cord unplugged ain:

Vince

 

^ thanks

I checked and it doesn't seem to be the same issue as you experienced

 

If you have a volt/ohm meter check for continuity when the switch is closed between the upper and lower wiring connections on one side of the switch. I still bet that one of those spring loaded tabs are not contacting the upper and lower contacts.

Vince

 

It is definately the pressure switch. That's all it can be if you can push the contacts closed to get it to start. Replace the switch and it will solve your issue.

 

IR quality my butt.. this thing is about 1.5yrs old

 

Ok, so I called IR and they only provide 1yr warranty on the switch, 2yr on the motor.

That means I'll either cough up the money for an IR unit (#54441738) or get another brand. They quoted me $106.00+tx cdn, which is about $87+tx usd for a replacement.

Can anyone recommend a reliable switch in a relatively small form factor (preferably)

 

i have the same compressor, and my pressure switch has crapped out on me several times.

 

^ did you ever replace the switch? if so, was it with the same IR part or another brand?

 

Check your local industrial/electrical supply, it is a common switch. The same type is used on a well water pump, just with different pressure settings.

 

Which one of these would suit my application best? I found these at my local Princess Auto (harbour frieght equiv) #8050742? (see attached image)


The one in the link provided has a factory set psi on at 70 and an off setting at 100, I take i that one could adjust this for 135 or so? Or does cut-out range mean something else?

Wouldn't I need something with an adjustable ON/OFF PSI setting? As in I would need something to turn on at 90psi and stop at 135psi or so?

https://www.surpluscenter.com/item.asp?UID=2009040911290359&item=436-DS&catname=

# Rated 1 1/2 HP at 115V
# Rated 2 HP at 230V
# Factory set PSI ON 70
# Factory set PSI OFF 100
# Adjust. Cut Out Range 70-150
# Size 3 3/4" x 3 5/8" x 2"
# Shpg 1-1/2 lb

 

Can anyone recommend a reliable switch in a relatively small form factor (preferably)

You can cross reference your switch to a Square D brand switch.

GRANGER has many listed.

 

Did you ever check the continuity between the contactors to see which leg is not making contact? I would not be so quick to replace the switch, there isn't very much to them. They are easy to troubleshoot. That price IR gave you is ludicrous IMO.

Vince

 

What you linked to is close, but has no ability to individually set the on and off points, they are fixed at 30 psi differential from each other. If you set the on at 90 the off would automatically be 120. You got the idea, though.

 

Check your local industrial/electrical supply, it is a common switch. The same type is used on a well water pump, just with different pressure settings.

NO! It is not the same as a water pump switch because it has to have a provision for an unloader for the pump, besides it is dangerous to try to adjust that much pressure into a switch that is designed to operate at less than half what an air compressor uses. Without that unloader the motor will be damaged from excessive start-up torque. Use the right switch and don't try to "make" something work because you can damage your compressor and maybe yourself, NEVER try to use a water pump switch on a compressor! :nono:


Don't know if they deliver to where you live but these guys will have what you need at a decent price.

www.surpluscenter.com


This one maybe?

www.surpluscenter.com/item.asp?UID=2009040918314010&item=4-1798&catname=


www.surpluscenter.com/pages/093.pdf


A heavier duty switch with different settings.

www.surpluscenter.com/item.asp?UID=2009040918344360&item=436-LMV&catname=

 

Oldred, good link :thumbup: , $14.95 sure sounds a lot better than what IR quoted him . And it's a Siemens, should be better quality than the POS that IR supplies with their compressors. I just ordered one :thumbup: .

Vince

 

OK, since we have established in the initial post that the motor runs when the contacts are closed manually, and that the contacts open when the receiver gets to 135 PSI we know the power line is good, and the motor is good, and the problem is with the switch.

We also know this is the standard piece of crap switch provided by the cheapest crap vendor the manufacturer found for that batch, so it won't be repairable at any level of cost effective.

Since the cover is off the switch, and the wires are all pulled back from the mechanism, chances a wire stuffed into the mechanicle portion of the switch causing the problem are pretty low.

SO

Replace the switch!

No. well switches are not a substitute, the springs for shutoff and differential cannot handle 100 psi functions.

So
if your preference runs to Furnas.
http://cgi.ebay.com/Air-Compressor-...or-Pressure-Switch-14G-replaces-FURNAS-4WAY_W0QQitemZ250337612964QQcmdZViewItem

if you like Square D
http://www.drillspot.com/products/121518/Square_D_9013FHG12J52M1_Air_Compressor_Pressure_Switch
(this one is in the proper pressure range)

If the switch that crapped out has an unloader, spend a few bucks from what you didn't spend getting raped by IR and put a Load Genie on the machine. It will give you softer starts and probably double the time to failure on the electric motor bought by the same purchasing agent who put the crap switch on the machine.

 

Jeez, I never said to use a well pump switch, just that it is the same type of switch. Only switches with the correct pressure and power capabilities should be used of course. Just getting info to the OP on what to look for and that it didn't have to come from IR.

 

Oldred, good link :thumbup: , $14.95 sure sounds a lot better than what IR quoted him . And it's a Siemens, should be better quality than the POS that IR supplies with their compressors. I just ordered one :thumbup: .

Vince

I buy a lot of stuff from Surplus Center, you never know what they will have in addition to the things they normally stock. For someone who likes to tinker with machinery and build things they have everything from electrics to hydraulics and all the gears and other gadgets to make it all work! Their prices are hard to beat on most of these items and they are really good people to do business with.



I had a comical experience with them last when they had some Autometer gauges at give-away prices (like $9.99 for engine gauges and $29.99 for a 10,000 RPM tach). I ordered a voltmeter and the stock no. was 250-****** (anyway it started with 250) and when the UPS truck arrived a few days later he left a HUGE box! Yep, they sent me 250 of the darn things! I called them up and they were very apologetic about it and of course immediately credited my card for the error they then gave me a nice credit for my next order for my trouble in returning these things, at their expense of course. Thinking back on it I should have kept the darn things and sold them on E-bay because they were sold out of every kind of gauge they had in just a few weeks, those things sold fast!

 

Jeez, I never said to use a well pump switch, just that it is the same type of switch. Only switches with the correct pressure and power capabilities should be used of course. Just getting info to the OP on what to look for and that it didn't have to come from IR.

Didn't mean to sound like we were picking on you but you would be amazed at how many times a water pump switch gets cobbled onto a compressor, it can be made to work-sort of anyway. Actually although they do look a lot alike on the outside there are several important differences between a well switch and a compressor switch, such as the unloader, and I just felt it was a mistake to compare the two since that could possibly lead to a misunderstanding.

 

Enlighten me please. what is a unloader? My knowledge is lacking.

 

Short answer, it releives pressure from the compressor head so the motor doesn't have to start against a load.

 

Basically it does exactly what Cobalt said.


There is a check valve in the tank where (usually) the supply line from the pump connects, this valve allows air to flow into the tank from the pump but not back the other way so pressure can not return to the pump. The unloader then is a small valve in the pressure switch that is connected to the line from the pump to the tank, or the pump itself, that will be opened when the pressure switch shuts off power to the motor so that the pressure remaining in the supply line and the pump will be released (this is the short "hiss" you will hear when the motor/pump shuts off). This is done so that when the motor restarts the pump it will not have to do so with the pump loaded with pressure from the tank which would take a good deal more torque to accomplish. Failure of this unloader is probably the leading cause of motor failure and is one very big difference in air compressor switches and water pump switches.

 

Thanks, I learned something today.

 

Since we are in teaching mode today, I recommend removing the cheap checkvalve on a compressor and replacing it with a load genie.
http://www.drillspot.com/products/35521/Control_Devices_CA121A_Unloader_Check_Valve
Make sure to get the proper size when you order!

Where the switch mounted releif valve merely unloads the compressor head and piping, the load genie gives you a easy start by keeping the compressor unloaded until it reaches full speed.
This reduces starting current and starting torque required from the motor.

I've seen both motor and compressor shafts twisted off in starting, and a load genie will prevent that by giving the machine a soft start.

 

Thanks for all the info guy!

Funny enough I work for Siemens (business div though, so I wonder if I can get it direct and with an employee discount). The current switch is made by Hubbell which I thought was a good quality company?

This "Load Genie" thing, where does it go exactly? I thought it just eliminated the need for pressure switch unloader and receiver check valve (which my unit already had - see photos)


I added some more pics for your viewing pleasure, but with that said im also going to annoy you guys with more questions

Sorry again for the n00b questions.. lol