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Discussion Starter · #1 ·
I was given a Sanborn 5hp Black Maxx compressor from work. It's a 2 stage and was rated 20 CFM at 100 PSI. We used it as a secondary until the motor quit starting. Bossman wanted a shiny new IR model with an after cooler to match his old one so I got this one.

The compressor head on it works, but it needs rebuilt as it blows oil externally. I have the motor at the electric repair shop getting whatever it needs, probably a capacitor.

BUT, the pump rebuild alone will cost more than a HF twin cylinder single stage that generates 15 CFM, and since this is just for my garage, turned on once in a while, that will be fine. I have a 110v compressor that does 5.3 SCFM @ 90 that I could tag in should I really need the extra 5 CFM.

My question is the speed.. The original pump ran at 1,147 RPM per the tag and the motor is 3,450. The HF pump has a max of 1,050.. 97 RPM going to blow it up?
 

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97 rpm isn't going to make any difference AFA longevity , do some Reding on CFM vs SCFM , there's a world of difference , a 2 - stage generally is a much higher output. What's wrong with the 2-stage pump ? Electric motors need cool CLEAN air to survive , the windings become coated with dirt/ dust , loose their cooling ability , overheat & burn out , my guess is the old motor is probably toast ! Good Luck ..
 

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Discussion Starter · #3 ·
CFM and SCFM are basically the same. one says standard, and the other there isn't a standard. ACFM and assisted CFM are the sticky issue. But somewhere over 12 SCFM is all I really need.. The old pump puts air out just fine, but we repaired it once in the shop. The valves in the head were sticking so I pulled the head off and my bosses/ company owners friend/ ex co worker rebuilt the valves and got them working. It pumps air just fine but it sounds like a rod knock and it blows oil down the side.

As for the motor, it started with an assist spin so it probably just needs a capacitor. The repair shop seemed to think it was fixable. It's a 5hp ( actual ) USA made motor so hopefully
 

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Discussion Starter · #4 ·
Also what is the thought on PEX air lines? I really want to go copper, but PEX is so cheap, and I have the crimpers. Seemingly getting popular too. I need ~50' of air line not including drops. The compressor will be on the oposite side of the garage than the work bench/ work area BUT I will probably put a drop on the compressor side as well
 

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CFM and SCFM are basically the same. one says standard, and the other there isn't a standard. ACFM and assisted CFM are the sticky issue. But somewhere over 12 SCFM is all I really need.. The old pump puts air out just fine, but we repaired it once in the shop. The valves in the head were sticking so I pulled the head off and my bosses/ company owners friend/ ex co worker rebuilt the valves and got them working. It pumps air just fine but it sounds like a rod knock and it blows oil down the side.

As for the motor, it started with an assist spin so it probably just needs a capacitor. The repair shop seemed to think it was fixable. It's a 5hp ( actual ) USA made motor so hopefully
Well OK , you're obviously way more knowledgeable than I , so I'll refrain from further comment , Good Luck !
 

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The horror freight compressor isn't worth the ride to go buy it, even if you live next door.

Where do you mean that the current one blows oil externally? Where do you see oil?

Last year I rebuilt my 1974? Saylor Beal compressor and just the parts probably cost as much as a horrible freight compressor. But it runs great. It didn't take oil and put out plenty or air, but it would knock real pretty loud on start up. Bad piston, rod, and pin. If it stays in home use, it will surely outlive me, my son in law, and my grandson. The horrible freight ones, well I've heard lots of stories of the compressors going south, and it's impossible to even buy parts for them, so if you want to buy a new one every year, go for it.
 

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Discussion Starter · #7 ·
There is oil mist over the discharge side, so it's likely discharging oil into the air as well. It used a little oil as well.

My boss ran it without a filter, and I don't even have the filter housing. He sent it off to his friend/ ex coworker to re fit it for a different filter and that didn't happen. The filter material was desintegrated and the pump sucked it up when we first got it running... I'd rebuild it if it were really worth rebuilding but I don't think it is, and if the motor comes back as not fixable, I'll haul it off for scrap because it won't be economical to rebuild the compressor at that point

I could get the comparable Northstar pump
 

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Oh! I just did a search on the Sanborn and now I see it's a disposable one like the $1500 chinese Ingersol Rand's. If the motor is good, you might be able to buy a decent compressor for it for ~ $1000. I don't know about the Northstar pumps, but I would get all the info you can, then act like you have one that needs to be rebuilt to see if parts are even available.
 

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Discussion Starter · #9 ·
I see Harbor Freight fire saled the last of the 2 stage 60 gallons they used to sell back in June for $700. I knew they were going to go away. They were the Bel-air's that were built for HF.. The Bel-Air variant is $1,500

I don't want to put a ton into this. I actually have 2 of the smaller 3hp HF pumps I have never used. They are 10 CFM according to HF.. I could always just bolt one up and run it
 

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Discussion Starter · #10 ·
So, I forgot to report the motor is running. The starting part of the motor was out of wack, so it would not start. $70 for some diagnostic, and adjustments and it's good to go.

I need to run the compressor through a lead cord type arrangement since my 50A 220v outlet is on the opposite side of the garage. Is 10ga romex going to be ok, hooking it to a 50A plug?
 

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I need to run the compressor through a lead cord type arrangement since my 50A 220v outlet is on the opposite side of the garage. Is 10ga romex going to be ok, hooking it to a 50A plug?
The wire is the minimum for 5 hp if it's not too long. My 10 gauge is about 45' long total. A 50amp breaker is too high. It should have a 30 amp, and if it does trip, a 35 amp breaker is allowed per NEC (I think it's just for motors but not sure). Probably have to order that but they do make them.
 

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Discussion Starter · #12 ·
I ran a 6 disconnect breaker box, and only have the one 220v 50A plug, connected to a 50A breaker. I don't have room for another breaker. Which Is why I'm going to wire it to a plug. I have to keep it 50A to run welders and stuff. I've got about a 20' run across the garage. The plug is fed by 2' of 6/3.
 

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I don't quite understand your wiring but it will work, it's just not safe. And if the motor stalls or runs slow for some reason it could burn up before the breaker trips. I believe the 50 amp breaker on a 10 gauge wire is only allowed with a welder with a 20% or less duty cycle. That way the wires cool during the downtime period. I put one on my stick welder because that's what the welder instructions said, but in all reality, unless I weld at a setting over (about) 150 amps, the 50 amp breaker probably isn't needed.
 

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Discussion Starter · #15 ·
I don't quite understand your wiring but it will work, it's just not safe. And if the motor stalls or runs slow for some reason it could burn up before the breaker trips. I believe the 50 amp breaker on a 10 gauge wire is only allowed with a welder with a 20% or less duty cycle. That way the wires cool during the downtime period. I put one on my stick welder because that's what the welder instructions said, but in all reality, unless I weld at a setting over (about) 150 amps, the 50 amp breaker probably isn't needed.
I sized the only 220v circuit I have to be able to handle my grandfathers old A/C 225 tombstone, so that's why it's a 50A receptacle/ breaker and 6/3 going to the circuit. The compressor needs to utilize that plug, and any other 220v equipment I might buy, so I will run an appropriate sized wire with a 50A plug on the end and probably coil it up when I don't need the compressor.. The welder will either plug directly into the wall plug, or a lead cord that I will make out of about 15' of leftover 6/3.

The motor on the compressor does have it's own breaker
 

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OK, I think I got this figured out. You want to use the romex wire for an "extension cord"?
If so, I wouldn't. It's not meant for that amount of bending back and forth. You would want some stranded wires. Although I don't know if that would adhere to the electrical codes?
 

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Discussion Starter · #18 ·
The romex for the compressor which should be 10ga I think, will be wired to the pressure switch at one end, but the other will have a 50a plug end.. The welder, I do have 15' or so of leftover 6/3 I was planning on making a lead cord out of with plugs at both ends
 

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The romex for the compressor which should be 10ga I think, will be wired to the pressure switch at one end, but the other will have a 50a plug end.. The welder, I do have 15' or so of leftover 6/3 I was planning on making a lead cord out of with plugs at both ends
The romex is not made to be mobile at all. It should not be wired into a male plug. It's a bad idea. There is a reason they make stranded wire.
 
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