Old Compressor

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I was "lucky" enough to find an old compressor in my area for $100. It is a 60 Gallon upright that had a seized motor. The motor is HUGE all cast iron and weighs a ton. But the nameplate is gone from the motor and I can't find any info on the compressor itself on the interweb. The wiring is funny too. Somebody had a 2 wire going into the JB on the motor white to green, black to black and the white in the motor jumpered to itself. It looks like it was run in this configuration but I'm not sure how it would have worked! It must be 220V how could it be run on 2 wires?I took apart the motor and it has 2 brushes and found that the rear bearing had seized. I was planning on getting a new motor but hell if I can spruce this one up and save $350 what the hell right? The motor guts seem to be in pretty good shape. Some surface rust but the windings look ok and there is nothing visibly damaged, besides the bearing race seized to the shaft.It is a splash lubricated piston compressor with a primary and secondary piston. The primary is maybe 2.5-3" diameter and the secondary is maybe 1.5" diameter. The air transfers in large copper tubing with heat fins on it. It looks a lot like this Quincy http://www.quincycompressor.com/PLT-cutaway-lrg.jpg.The company that made it is Gilbert and Barker MFG Canada. Looks like this company has morphed several times and now mainly makes gas station pumps etc.How can you determine the HP required to run the pump?How much does a motor rebuild in the 5-10hp range cost? To my eyes it doesn't even need to be rewound. Attached Images
Reply:I wonder if it could have been a DC motor. Brushes could mean either AC or DC   . . . .  I know DC was being used in Boston 50 years ago, it still might be around somewhere-- fredLincoln 180C MIG
Reply:Cost on an electric motor rebuild?  Call an electric motor rebuild shop.  As to the HP required to run an air pump, that would be about 1.5 motor HP for about each 5 cfm @ 90 psi out of a typical pump.  Typical 60 gallon compressor tanks -usually- use about a 3-5 HP motor.As to the two wire set-up, if the motor is old it might use just two wires and not have a safety ground wire (green wire in the current world).  The best laid schemes ... Gang oft agley ...
Reply:Even without the ground wire it is still weird that is was run on 2 wires. Assuming that it should be 220V for 220V (not a welder) you would need 2 blacks and a white, plus the ground, correct? But then again it does only have 2 brushes. How does the negative play into brushes? Is the negative a brush of it's own or are the brushes both hot and the negative comes out some other way?
Reply:220V uses two wires.  No neutral is used.
Reply:salem,220-240V single-phase AC is just two hots.  No neutral needed, no ground needed.  Two wires does it all.For things that -also- use 120V AC while they are using the 240V AC, current Code says you need the two hots (for the 240V) -and- a neutral (to get the 120V).  Current code also says you need a green/bare ground wire.  So a 'recent' 240V household electric stove or clothes dryer has 4 wire: hot, hot, neutral, and ground.But a 240V electric motor doesn't need 120V, so no neutral need.  And an 'old' 240V electric motor might not have had a ground wire.Thus an 'old' 240V single-phase (or DC if it is indeed a DC motor) motor just 'needs' two wires.  The best laid schemes ... Gang oft agley ...
Reply:Ah ha. That makes sense. Pretty small wire going into the motor too, maybe #12.Talked to the motor shop in town and he said as long as nothing is totally blown or destroyed it should only be $100 or so to figure out what it is and get it running again. Better than $350 for a new motor that I would need a new pulley set for and may not even be the right HP rating.
Reply:I can't help withthe motor, but from your description it sounds like you have a 2 stage compressor rather than a single stage compressor. That means you'll probably get 175 PSI from it, as opposed to the 125 or so that you'd get from a single stage comp. The down side is that they usually make a bit less cfm at say 90 psi than the 2 cylinder single stage units..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Originally Posted by salem747Even without the ground wire it is still weird that is was run on 2 wires. Assuming that it should be 220V for 220V (not a welder) you would need 2 blacks and a white, plus the ground, correct? But then again it does only have 2 brushes. How does the negative play into brushes? Is the negative a brush of it's own or are the brushes both hot and the negative comes out some other way?
Reply:For $100 I am going to leave it up to the "experts" no experience with this outfit but they have a storefront etc. He figures he can tell me the hp rating by the frame and get it going again for $100ish.
Reply:OK, so I have traced down what happened to the air compressor part of GIlbert & Barker known today as Gilbarco. It became Quincy compressor! No wonder the Quincy Max 5hp looks identical! Gilbarco forwarded me to Quincy but Quincy has no records of compressors going back that far so it is sort of a dead end. But even the bolt patterns on the Quincy Max look exactly the same from what I have found. I wonder if I could get real drawings and confirm the measurements. I could maybe even use some of the same parts as a new Quincy!
Reply:Quincy compressors are the best.  If you can't get that motor running you should just be able to get a set of taper-lok sheaves and any electric motor that meets the horsepower requirements.  If you want to rebuild the motor, start by throwing a set of brushes at it.  Bring in the remenants of the old ones.  I have a local shop called Advanced Carbon Products.  You don't even need to know the original dimensions.  Just bring in the old ones and they'll make new ones while you wait at a cost of about $9 for a pair.If you intend to try to use new Quincy parts on it, know that the basic compressor generall doesn't change but over they years Quincy has made many changes to the unloaders, valves, and oil pumps.  They new assemblies can typically be bolted on to the old units but you will approach the cost of a new unit if you try to upgrade.  We use the Quincy 325's exclusively at work.  To rebuild one costs around $1500.  A new one costs $1700 delivered.Last edited by 76GMC1500; 01-08-2010 at 12:47 AM.
Reply:The motor is at the rewind shop right now. The guy said if it can be fixed up that it is the very best way to go. He says they stopped making motors with those big cast iron casings because it costs too much. He said a 5hp that I would buy off the shelf wouldn't last long and that I would need a heavy duty motor to make it happen. He thought it could either be 3 or 5 hp.
Reply:OK, motor all fixed up, new bearings, inside cleaned and painted were necessary, outside painted, $40! It is a 3hp motor, the motor guys figure a 25A circuit would probably work but 30A would be better. He showed me how to change the rotation if necessary, pretty easy to do, so on to the receiver and the pump!
Reply:Originally Posted by salem747OK, motor all fixed up, new bearings, inside cleaned and painted were necessary, outside painted, $40! It is a 3hp motor, the motor guys figure a 25A circuit would probably work but 30A would be better. He showed me how to change the rotation if necessary, pretty easy to do. . .
Reply:$40 isn't bad.  I tried to have a 7.5 hp motor rewound not long ago but the quote came back at $2400.You can still get decent motors.  Look for TEFC or totally enclosed fan cooled motors.  These are typically the heavy duty cast iron type.  Baldor/Reliance and WEG are considered the best at this moment.
Reply:My company does work with this place so he just charged me for parts. I wish I knew what motor it is ie brand etc. They didn't have to rewind it, obviously that would be a LOT more, just bearings, some paint, some varnish and a few screws.Yes there is an inspection plate that you open and there is a screw that you loosen and then you line up another set of marks on the brush holder.The motor guys said this thing will have a really low starting inrush. Running no load at the shop on 230V it was drawing about 9 amps. He said it would be hard to find a motor that would last like this one. I really want to weigh it, it's friggin HEAVY!
Reply:OK. So I figured out how old this thing is. It was certified with a CRN number. This is the number that registers the vessel as a pressure vessel in Canada. As you can sort of see in the picture that happened in 1958!!! My Dad was 11 when this thing was made! Anyway, I dug into the pump today and started cleaning it up and polishing the mating surfaces. It's a very simple design, but hella strong looking, fully cast cases and forged rods. The rings look pretty good but I don't know where I would get a ring gap spec for something like this. I am going to try and dig up a copy of the Quincy manual/parts list that "looks" the same, maybe some of the info would be useful, maybe not. My only problem is how do I blast and paint this compressor, well I need a compressor to do that, maybe I should find an old one and fix it up? You see my problem. I might do some of this stuff at our North Bay shop.PS, Moly anti-seize will be applied liberally to the reassemble of this puppy! Attached Images
Reply:more pics Attached Images
Reply:Originally Posted by salem747PS, Moly anti-seize will be applied liberally to the reassemble of this puppy!
Reply:Not for bearings or cylinders, just for some of the stubborn threaded plugs, bolts, etc
Reply:OK, so I weighed the motor. 3HP and 117.5 pounds!!! Brings new meaning to "They don't build them like they used too".Bad news though, when I tried to put the oil ring on the small piston it broke in two! Now I have to figure out where or how to get a replacement.
Reply:Originally Posted by salem747OK, so I weighed the motor. 3HP and 117.5 pounds!!! Brings new meaning to "They don't build them like they used too".
Reply:I didn't ask them the rpm. I should have, I was just happy that they got it running again and since it is the original motor I wasn't too concerned but I should find out, in case I ever have a problem with it.
Reply:Originally Posted by salem747OK, so I weighed the motor. 3HP and 117.5 pounds!!! Brings new meaning to "They don't build them like they used too".Bad news though, when I tried to put the oil ring on the small piston it broke in two! Now I have to figure out where or how to get a replacement.If you cannot find direct replacements Niagara Piston Ring in Corry, PA could custom make them for you.  It's where I go for all my antique engines - they cut them to whatever dimensions I need.  And, it's not as expensive as it may sound!  Seems like it was about $65 for a set of 3 that were for about a 5" bore, and were 1/2" wide.
Reply:salem747,  why are the pistons 2 different diameters? dave.
Reply:The pistons are two different sizes because the pump is a two-stage pump.  The big piston pumps the air partially up to pressure and then that compressed air goes into the second smaller cylinder where the smaller piston then compresses it some more.  Sometimes there is a loop or piece of finned pipe connecting the air coming out of the big cylinder into the intake of the smaller cylinder in order to try and cool the air off a bit.  The best laid schemes ... Gang oft agley ...
Reply:rvpc MoonRise covered it pretty well. You can always tell a 2 stage compressor from the different sized pistons, and the fact that stage one feeds into stage 2 an then into the tank. A single stage, 2 piston compressor usually has 2 separate intakes, one for each cyl. and usually the out put goes into a T that then enters the tank.2 stage compressors usually make 175psi or more, but have lower CFM's than the same HP 2 cyl single stage compressors. The single stage units making 125 psi max or so. This difference makes a big difference in price frequently on new units..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:thank you.dave.
Reply:Yeah I am thinking for a ring I might have to get one fabbed. It's almost a shame that it is the oil ring because the other rings are just plain and would be cheaper to make. This one has a groove around the outside with small holes drilled through it. The big oil ring has a groove but more like slots cut into it.But I guess if any ring is going to break it will be the oil ring because it is quite a bit weaker than the compression rings.I have been out of town all week so I haven't done much research on it yet.
Reply:Update: Since the tank was no good I looked into a new one. Found out that the pump is a Brunner A-212. There is a company in Toronto that still makes rings etc for them apparently these are bought and last for a lifetime!I found another complete 3-phase Brunner horizontal in Ottawa about 3 hrs drive from home for $375. It is a little newer, 1962 or 1964. It was used in a agricultural college wood shop for cleaning off the tools, the wood shop has been shutdown for 10 years and the guy who had it is a HD mechanic who teaches there and got this machine in return for some extra work. It has the original metallic blue paint and all of the original decals (what ever happened to decals anyway?) I put on my 1958 3hp motor and a couple of new belts and it runs like a champ, very quiet! The only problem I had besides getting all of my fittings clocked properly with no leaks was that they had broken the original plumbing from the head to the tank and replaced it with soldered copper pipe. So when I soldered the pipe back on (wouldn't fit under the canopy on my truck without disassembling) I kept getting little chunks of solder in the check valve so when the motor stopped the unloader valve would open and let all the air out. I am no plumber so I was obviously using too much solder. Just put it back together and heated the joints, no additional solder. Seems to be holding air now.I still want to finish the A-212 pump. It is a 2 stage pump for 175psi and I can probably get some good coin for it or just keep it!Pics to follow.
Reply:In case anyone else has an old Brunner and you are looking for parts:http://www.atmosphair.net/ they are near Toronto and do have gasket sets, rings etc. Attached Images
Reply:great thread .  sorry, i PM'd you before i saw this thread.what size did u say tha tank was?        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:60 Gallon tank. This pump is a 2 cylinder single stage unit. I don't really need 175PSI but I am going to try and get the other pump running.I would like to figure out how many CFM it is capable of. I could probably calculate it. The intake will suck your hand right tight!This has been a really fun project. Some detective work, some history lessons, a little mechanical stuff and I saved myself a couple of grand in the process!!! Not bad.
Reply:i think the formula is :  CFM displacement@ 0 = Bore x stroke x actual pump RPM (but would be a drop @90psi) gotta find the formula for that.pump speed is calculated :  pump speed =  diameter of the pulley on the motor X the speed of the motor (via;1750 or 3450)  /divided by the diameter of the pulley on the pump.-that's not the same pump on page 1 ?        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:Nope, still need the oil ring for the 2 stage pump. I can't find the bore & stroke of the newer pump without taking it apart and have yet to find any manuals for these old pumps.
Reply:pv = pv , pressure in psia (absolute).   0psig (gauge)  (atmospheric) is 14.5psia   90 psig is 104.5 psiamy old pump = 3" bore, 3.5 stroke, single cylinder and is supposed to run at 550rpm  24.7 cu in displacement x 550 rpm =13585 "3 = 7.8 cfm @ 14.4psia14.5 psig* 7.8 cfm  = 104.5 psig * 1.08 cfm should put out 1.08 cfm @ 90 psigHmmm how many HP should I drive this with???Last edited by fredf; 02-11-2010 at 10:41 PM.-- fredLincoln 180C MIG
Reply:somethings wrong...............noway it should drop from nearly 8 CFM to  1cfm..my brains tired right now.  I think i remember the rule's like 1HP or 4.3 amps per/ 3 cfmi think thats 220V        - the amps required on a 110 motor would nearly double to like 7.5amps per HP , yes i may correct this later , dont hold me tooit.        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:Just got the new set of rings for the Brunner 212 pump. $74 CDN for a complete set (both Pistons) of brand new rings. I asked for pricing on the gasket set, $72 so I told them I didn't want them but they sent them anyway! Woulda been fine if they didn't charge me for them, but they did so I sent them back.
Reply:After you get the motor and pump all fixed up be sure and inspect and /or test the tank.  Sitting around for a while may have allowed internal moisture to rust the inside of the tank to the point where it won't stand up to the original pressure rating. Even if there is no evidence of moisture the damage could have already been done . Given the age of the tank this could potentially be dangerous.  Typically tanks do not explode but develop pin holes that gradually grow to the point where the tank won't hold enough pressure to operate anything.  However, older tanks were sometimes more brittle.