need replacement motor for air compressor

Discussion in 'The BS Topic' started by Chuck71RS, Apr 2, 2021.

  1. Chuck71RS

    Chuck71RS Veteran Member Lifetime Gold Member

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    Need to replace the OEM Century electric motor on a 2008 built Schrader-Bridgeport air compressor.

    The motor is no longer made for it did not turn up searching on series or part number

    As for hp, the motor plate shows "spl". The compressor tank tag has...... "2 hp running 5hp at peak". Amps 19.0/9.5. The compressor has a single run position with capacitor start.

    Called Regal (who now makes Century). Left a msg Thursday morning what replaced the OEM but no answer.

    How do I determine the needed electric motor? OEM is single phase, 115/230v, 3450 rpm, 56m frame (physical dimensions match 56).
     
  2. gramps

    gramps Veteran Member

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    When mine blew I took it to these guys. I’m sure you have somebody in your area that repairs them, but if not the contact info is listed. They put in new bearings and a cap had me back up n running in a day. If I remember right was about $120. Was much more reasonable than a replacement motor.

    74DFD518-0AD9-466F-A5E7-428FC9E33AFF.png
     
  3. M1 Master Gunner

    M1 Master Gunner Veteran Member

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    Normally you need your frame size, rpm, and voltage. Yours must be a 5 horsepower but you will have to determine whether you are 120 volts or 230 volts. Once you get the frame size it bolt right to your existing mounts.
     
  4. grzewnicki

    grzewnicki Veteran Member Lifetime Gold Member

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    I'd first check with my local electric motor repair shop. Had a motor go out on a Cmpbell Hausfeld compressor right in the middle of using it to do knock down texture ceilings at my M-I-L's house. $30 for repair, simple switch in the motor (centrifugal switch for putting power to start cap), Like laster gunner said if you know all the motor specifics finding a compatible replacement on line is relatively easy. Every motor out there is sized according to the specs he gave and finding a replacement is easy on the web, doesn't have to be the same brand that came off. If you can aford it stick with a well known American brand.
     
  5. Phil G

    Phil G Veteran Member

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    I used to work for an Industrial Supply house here in Atlanta that was a Reliance/Dodge distributor. I was a Sales Engineer and they sent me to the Reliance "training Center (somewhere on Ohio IIRC). Old hotel out in the middle of nowhere that they had converted years back because the Interstate bypassed it. Half the place was still hotel rooms and the other part converted to classrooms. Dining area (and BAR) in the middle. Spent a week there and got the same training Reliance's field techs did. All at Company expense (and no limits on the bar either).

    In five years we only got one "defective" motor back. Out of the box failure. 1 Hp, cap start. C-face/D-flange style, no mounting foot. Single phase, could be wired 110/220V and either 1800 or 3600 rpm (~). So curious me took a look at it and the cap wasn't plugged in! Called Reliance and asked them what to do. They didn't want fractional or small HP motors back, just told me to send the nameplate to them and pitch it! The damn thing worked though! Talked to my boss and he asked if I wanted it (we got credit for it anyway). I took it home and I still have it waiting for some "one of these days" project to come along...

    :rolleyes:
     
  6. Gary S

    Gary S Administrator Lifetime Gold Member

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    That is likely about a 2hp motor. The "running" hp is what matters. The "peak number" is the theoretical power it should apply to the shaft when it is stalled under load just before it trips the breaker or burns up the motor. Nobody cares about that.
    Also, it says 115/230. You can't run a 5hp motor on 115v so that tells the story. The current rating of 19A also suggests it is about 2hp as that is the limit for 115v. Even at that, you are pushing a 20A circuit to its limit. For this type of motor, I would run #10 wire from the 20A breaker to lessen voltage drop as lower voltage to the motor due to heavy load will shorten the life of the motor.
    A motor rated around 2hp with the correct frame and shaft size should work for you.
     
  7. gin man

    gin man Veteran Member Gold Member

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  8. sandlapper

    sandlapper Veteran Member

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    Suggest take your old compressor motor to a local commercial-industrial electric rewinding service for diagnosis.

    A fellow gave me a small commercial two-stage Kellogg American compressor head; I troubleshot & fixed it for nothing. It required a true 5 hp motor at the slower 1825 rpm. I wanted it to run on 220 (Not 3-phase). A couple years later, a farm neighbor was cleaning out his junk for first time in decades; he was about to haul a GE motor & other junk to scrapyard. I asked to buy it for whatever they thought its scrap value was; he said no, just take it. I insisted and gave him a twenty. So heavy, I don't recall frame #. His grown boys loaded it in my pu. This motor had powered a silo auger. The shaft felt like maybe bearings. I hauled it a couple miles to large rural electric rewinder. They screwed a lifting eye into it and hoisted it onto their test bench. The elec tech there said bearings feel a little rough but let's try some grease. He powered it up and away she went; he pumped a shot of grease into each end and I could both hear & feel it ... all good. Tech said it was good & no charge; but if it needs bearings just bring it back & he'd put bearings in it for about $75. He also told me GE didn't make that exact motor any longer but that a somewhat lesser version was about $1000 new ... $1000 ! :eek:

    Take yours to a pro; maybe it can be fixed for small $.
     
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  9. Fbird

    Fbird Veteran Member Lifetime Gold Member

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    I'm the cheap bast*rd...get out your screwdriver and meter!!!!.....It doesn't work NOW....so....it's NOT like your going to screw it up any more. Open it up check around...SMELL around...Not much to those little things other than checking the start cap..
     
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  10. budro6968

    budro6968 Veteran Member

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    I found a small compressor in the junk a while back. I got it home. Plugged it in and nothing. Did what you said. opened it up. Nothing looked or smelled bad. Cleaned it out with some compressed air. Noticed a crack on the red reset button switch assembly. Put it back together plugged it in and pressed the reset. It started but as soon as I let off it stopped. I held it in and it would run till cut off point 150 PSI. It kicked on by it's self when letting the air out down to point when it is supposed start. worked fine for a while. The next day I had to do the same thing to get it to go. Simple replacement of the reset switch would have fixed it. One of my buddies stopped by one day and said what? another compressor? How many you got now. That made it # 4. He said why not give it to me. So I gave it to him. To this day he still never replaced the switch and does what I did every time he needs it.
     

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