# 220V Pressure Switch



## jefferywdonald (Feb 3, 2021)

Hello all, I have a large compressor in the basement that wouldnt shut off. The pressure would just build and build until the safety mechanism opened. I have a picture of the part that isn't working correctly. This `is a 220V switch. The compressor is old and the brand name is ATD. Any information on what switch I can use to fix this would be awesome.


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## stevon (Mar 5, 2019)

jefferydonald,

Welded closed (on) contacts is common with compressors that don't use a magnetic starter, that's why all commercial compressors over 2 HP come with one from the factory. An electric motor at locked rotor amps (start from 0 rpm) "rule of thumb" draws initially 10 times the FLA listed on the motor, so a 10 amp FLA motor at startup draws up to 100 amps! this is enough to do some welding on the contacts and why a 30 HP generator+ is required to start a 5HP compressor. What is the HP and the FLA listed on your compressor electric motor? Also you will see a pressure switch rated for 15 amps but only listed for a 1/2 HP electric motor.

Stephen


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## jefferywdonald (Feb 3, 2021)

Managed to get a few pics today, this tank is buried in the basement but I want to get this thing running. Here are the specs on the tank.

5HP Motor
230V
15AMP
60Hz
1 Phse
60 Gallon
Tank WP 140PSI
Max Unit WP/Factory Setting 120/90 - 120

Got a few pics with all the info needed too.


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## stevon (Mar 5, 2019)

jefferydonald, 

The motor may be marketed as a "5 HP" but in reality it is at best an efficient a 3 HP motor output. You can load this with a 5 HP load but it would overheat in minutes and trip thermal overload. The cheap fix is to replace the pressure switch but this is on the borderline of requiring a magnetic starter. It really depends what you need the compressor for. Used for hobbies or a business demand load? Do you want it to run every day for years trouble free? If so a magnetic starter and a new pressure switch would be the way to go. a cheap pressure switch will work with this








New Magnetic Motor Starter Control 5hp single phase 230VAC Compressor Motor | eBay


34 AMP MAX 220-240 VOLT COIL RANGE SINGLE PHASE POWER 5HP APPLICATION. PHASE: SINGLE PHASE (2 POLE). FOR AIR COMPRESSOR APPLICATIONS WITH PRESSURE SWITCH. YOU HAVE 2 OPTIONS TO CONNECT YOUR LEADS FROM THE PRESSURE SWITCH/TOGGLE SWITCH.



www.ebay.com




and a:








Lefoo Quality Air Compressor Pressure Switch Control 95-125 PSI 4 Port w/ Unload 1978091806865 | eBay


For all global air compressor applications. LF 10 Four Port Series. Port Type 4-Port 1/4 In NPT (Female), 1/4" Compression Unloader. UL Listed and CSA Certified. PRESSURE SWITCH. MAGNETIC SWITCH. PRESSURE GAUGE.



www.ebay.com




or you could just buy a heavy duty pressure switch alone, just make sure it is rated for 3HP, never mind the current listed value. These switches rated in HP shows the limit of it's design.



jefferywdonald said:


> Managed to get a few pics today, this tank is buried in the basement but I want to get this thing running. Here are the specs on the tank.
> 
> 5HP Motor
> 230V
> ...


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## stevon (Mar 5, 2019)

jefferydonald,

just replacing the switch it will eventually weld the contacts again but if you are a light to hobby user you may get years without a problem. This Square D pressure switch can handle a polyphase 3 HP motor:









Square D 9013FHG32J39M1X Pumptrol Pressure Switch,40 to 150 psi,1/4" FNPS | Zoro.com


Order Square D By Schneider Electric Pumptrol Pressure Switch, 40 to 150 psi, 1/4" FNPS, 9013FHG32J39M1X at Zoro.com. Great prices & free shipping on orders over $50 when you sign in or sign up for an account.




www.zoro.com






stevon said:


> Stephen
> 
> The motor may be marketed as a "5 HP" but in reality it is at best an efficient a 3 HP motor output. You can load this with a 5 HP load but it would overheat in minutes and trip thermal overload. The cheap fix is to replace the pressure switch but this is on the borderline of requiring a magnetic starter. It really depends what you need the compressor for. Used for hobbies or a business demand load? Do you want it to run every day for years trouble free? If so a magnetic starter and a new pressure switch would be the way to go. a cheap pressure switch will work with this
> 
> ...


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## jefferywdonald (Feb 3, 2021)

Hmm... Well this isn't used for a business or anything like that but I do use smaller pancake compressors and other portables for construction jobs. This big tank has been sitting in my basement for years but since I had a decent 21 Gal that I used for automotive things mostly I never needed it fixed. Well that compressor crapped out on me and its a cheap-o that has a electric motor and pump built into 1 unit so basically the whole thing is junk, I'll save the tank that's about it. But now this is a good time for me to get this bigger stationary compressor up and running. It sits in the basement and a retractable 100ft line will sit outside so I can take it wherever I need it throughout the yard. (Multiple cars/projects). I don't mind spending a bit to get it running, it's either that or what, buy a whole new setup for $350+. That square d switch looks decent, I've searched for switches but only saw cheap china junk on eBay and Amazon. This week I'll work on clearing out a bit of space so I can actually get in there and work on this thing. I'll get some more pics of the pump/belt too. Thanks


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## iowagold (Jan 22, 2020)

jefferywdonald said:


> Hmm... Well this isn't used for a business or anything like that but I do use smaller pancake compressors and other portables for construction jobs. This big tank has been sitting in my basement for years but since I had a decent 21 Gal that I used for automotive things mostly I never needed it fixed. Well that compressor crapped out on me and its a cheap-o that has a electric motor and pump built into 1 unit so basically the whole thing is junk, I'll save the tank that's about it. But now this is a good time for me to get this bigger stationary compressor up and running. It sits in the basement and a retractable 100ft line will sit outside so I can take it wherever I need it throughout the yard. (Multiple cars/projects). I don't mind spending a bit to get it running, it's either that or what, buy a whole new setup for $350+. That square d switch looks decent, I've searched for switches but only saw cheap china junk on eBay and Amazon. This week I'll work on clearing out a bit of space so I can actually get in there and work on this thing. I'll get some more pics of the pump/belt too. Thanks


make sure to not put the tank on a good large high pressure system!
the working pressure is only 10 psi!

yea you can go to northern tool and get a good compressor just to replace the whole thing..


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## stevon (Mar 5, 2019)

Paul,

10 psi? Jeff's compressor looks decent, I would choose to fix it and start by hydrotesting the tank but that's just me. I like the old compressors because they were made to be serviced. the one piece units sold today are like a Bic pen to be thrown out when your finished with it lol!

Stephen



iowagold said:


> make sure to not put the tank on a good large high pressure system!
> the working pressure is only 10 psi!
> 
> yea you can go to northern tool and get a good compressor just to replace the whole thing..


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