Advice on Ailing 5hp IR Compressor

[raynman1972]

Hello All,

I have a 5hp IR compressor I bought 10yrs ago that will overheat and throw the thermal switch on the motor if I let it run for 10-ish minutes like I did this weekend while using a die grinder mostly non-stop. It's always been like this I think and it is just becoming more of a pain now that I am using more air tools in my home shop. FWIW, it can fill an empty tank in a reasonable amount of time without overheating, but prolonged tool use seems to kill it. For what it is, I *think* the pump is performing within expectations.

https://www.amazon.com/gp/product/B001NGP8JI

My first option (advice portion) is that I could replace the motor for $300-400 with a Baldor off of eBay and then I would need to add a magnetic starter so it would round out to around $500.

My limp along option would be to *only* add the starter to my current setup to see if getting more juice flowing might be the fix.

Alternately, I could get a new 5HP Quincy ($2.3k-ish) and never look back.

The rub here is that I am really dragging my feet on investing $100-500 on what was a $1k compressor that I bought 10yrs ago even if it *mostly* fits my needs *if* it didn't overheat. I am also dragging my feet on investing 2x on a new compressor.

Any suggestions?

Thanks,
Ray

 

[redmondjp]

It sounds like you are overheating your motor, by exceeding the duty cycle of your compressor. I have a 30-year-old "5HP" (3.3hp actual) IR 60 gallon compressor that will run continuously while running a die grinder, but it doesn't overheat the motor - it just holds about 80psi and then starts spitting copious quantities of water out of the tool exhaust after running continuously for 15-20 minutes.

Can you post a picture of your compressor? That can give us a bit more to go on, regarding whether you should upgrade the motor or shop for a bigger compressor.

 

[bob15]

A picture of the compressor and motor would help.

My compressor is pushing 60 years old....so compressor age is meaningless. it is how it was cared for.

 

[TonyJ]

Is it a ir that was bought as a ir built one or is it one that someone has put together and was bought second hand. I ask because it could be if a 3rd party built it then maybe the motor is getting over loaded because it’s over speeding the pump because the motor has the wrong pulley on it. If it’s all factory built then some other problem is causing it

 

[Bigblockyeti]

On the motor nameplate is horsepower listed as "5" or "SPL"? If performance is steady but power consumption has changed to the point of tripping the overload, I would suspect a failing capacitor or something mechanical that's requiring the motor to pull too much current. If it doesn't currently have a magnetic starter, I would inspect the contacts on the pressure switch as they could be in need of cleaning. I would skip a new motor and figure out the root problem first as it's likely far less expensive. Even if you do go the Quincy route which certainly sounds appealing, fixing the old compressor and selling for $500-$700 would offset some of the replacement cost.

 

[Don1357]

The SPL stands for "the manufacturer is lying to you". Basically any given motor has a power spike right at the beginning before it settles in. What people understand as the HP of a motor is the normal HP as it runs. Manufacturers like to quote the much bigger "Peak Power!" number. It would **** if then the motor manufacturer turns around and stamps on the motor plate of the alleged 5HP machine say 2HP, so instead they say "SPL" for special...

Look up the duty cycle of your compressor, it may be running just as it is supposed to. If it says something like 50% duty cycle it means that for each 30 minutes of running time it needs to rest for another 30 minutes. 25% is 45 minutes of rest for each 15 minutes of work.

 

[Jswain]

Is the compressor used in a dusty environment? Have you tried blowing the electric motor out with air? Do you have it placed too close to a wall? They need some breathing room to keep cool. Also make sure the belts are not too tight and that the wire size is adequate powering up the compressor/clean all connections including terminals inside the pressure switch. If you haven't change the oil in the pump ever you could flush & put in some new IR all season select or equivalent. Check/clean air filter on pump as well because if it's dirty it will make the pump run hotter & if you have it too close to a wall could heatsoak the whole unit.

At least rule out all the freebies before throwing money at it. And if you have changed the oil and didnt use the Ingersoll Rand all season select they do (or used to anyways) reduce the duty cycle quite a bit ...

 

[Don1357]

I actually looked up your machine and it indeed supposed to be 100% duty cycle... One thing to try is to take apart the motor and clean all the gunk; buildup may be causing it to overheat. You may wanna fill up your tank before taking the motor out so you have some compressed air to clean with...

Yours look pretty identical to my oldie Campbell Hausfeld, except that my fake 7HP is higher than your fake 5HP

 

[Citation]

I would certainly look at the run cap. It should be a cheap fix it that's the problem.

 

[raynman1972]

Sorry for the delay in responding, I just got back from vacation and work is draining me a bit more than normal. I'm attaching pictures of the overall unit and then also of the motor plate (I hope this was what was wanted).

For general notes:

1. I had to replace the head gasket like 5hrs ago after blowing it out- not really a big deal.
2. The motor has always kind of run for 2-3 cycles and then thrown the switch at this house and at the old one (might rule out *some* electrical variables).
3. I had an issue recently where I had to cycle the on/off switch to get the motor to start (it wouldn't fire up at the low pressure point on its own), I took apart the pressure switch, cleaned, re-assembled everything and this seems to have fixed the issue. There was a little bit of corrosion, but nothing scary. Also, I glanced at the connections or points and wasn't alarmed or anything- but I didn't really get too serious.
4. Trying to remedy the overheat thing, I pulled the endcap off the motor and had a look at the thermal switch and then just the general insides and everything looked fine by my eye and while there was a lite patina of dust, it was far from concerning.
5. At the same time I eyeballed the capacitors to see if they were swollen or discolored and they looked fine.
6. I also lined the belt up as good as could and made sure the belt had an inch total up-down deflection.
7. Finally, I pulled the one-way valve at the tank and replaced it as it wasn't too expensive (a new pressure switch from IR is well over $100 which seems steep on a compressor that was around $1000-ish to begin with.

 

[DeeKay]

Check your amp draw while running and your voltage. Just because it did the same at two houses doesn't mean there isn't bad wiring at both houses.

 

[raynman1972]

I bought it off of Amazon but it was actually sold by Northern Tool back in 2010. I am assuming that it is a true IR and not some kind of "grey market" wannabe, but I guess there is always an option that it could be.

 

[johninct]

Could the compressor and not just the motor be worn out too?

 

[DeeKay]

Also forgot to add, if you have a Multimeter that can check capacitance, I'd check the rating on capacitors and then compare the actual capacitance; they can fail without any visible evidence.

 

[raynman1972]

My shop is kind of dusty, but I wouldn't think its that bad. I used to do some wood working and now I do a lot of grinding to fix my pos booger welding attempts, but I think its reasonable. Also when I pulled the back cap of the motor last weekend, it had what I would call a "patina" of dust but it's not caked in there or anything. I will give it a go this weekend with blasting it out.

Is the compressor used in a dusty environment? Have you tried blowing the electric motor out with air?

Yeah, its in the corner and it is about as close to the wall as it can be and not have it rub on anything and then there is a partial 2x4 shelf that hangs over the top a bit. I didn't take this too seriously originally as its always had this problem even in other locations. I have a 220v fan that I was going to put on an aftercooler back when I thought I was still going to fix this one up a bit- maybe I should do something with that...

Do you have it placed too close to a wall? They need some breathing room to keep cool.

I just reset everything last weekend to line up the pulleys and got the belt to be about 1/2" up and then the same down for deflection (1" total).

Also make sure the belts are not too tight...

I wired the shop, and while I can't remember now what I used, I set it up for a 50A breaker and then used the appropriate romex in the wall to an outlet box where I then have a massive (again, not sure the size as I am writing from work) welder-style whip that feeds the pressure switch. There are no other devices on this line/breaker and, FWIW, the wiring I did at the time passed inspection (I have just forgotten a lot).

...and that the wire size is adequate powering up the compressor/clean all connections including terminals inside the pressure switch.

I drained it recently but did not flush it. I filled it with some Royal Purple compressor oil. The filter looks fine to my eye (no visible loose bits and I can see through it if I hold it up to the overhead lights).

If you haven't change the oil in the pump ever you could flush & put in some new IR all season select or equivalent. Check/clean air filter on pump as well because if it's dirty it will make the pump run hotter & if you have it too close to a wall could heatsoak the whole unit.

 

[raynman1972]

Possibly? I mean, if I start from a full tank and run a tool long enough for it to cycle and then stop to let it catch up, it seems to reach pressure in what I would think would be a normal amount of time (i.e. the pump performance seems reasonably consistent over the last 10yrs, but I could be missing something). My problem is when I get to something around the 3rd cycle in something like a 10min window that it protests and throws the thermal switch.

Could the compressor and not just the motor be worn out too?

 

[Citation]

The pressure switches are largely generic and you can use a Condor or Square D to replace the one on the compressor. You want to check a number of little things like does the switch include a pressure release valve, how do the wires connect and how are they clamped, what is the default pressure range (this can be adjusted). Since you don't have a power switch on your pressure switch you could consider getting a model with a switch. Also, at 5hp you are right at the limit of what those switches can do. You might consider getting a contactor (one without thermal protection since your motor has that). You would then use the pressure switch to send a low current signal to the contactor to turn on the motor.

 

[redmondjp]

Yours look pretty identical to my oldie Campbell Hausfeld, except that my fake 7HP is higher than your fake 5HP

But look at the full-load amps of this motor: 21.5 amps.

My "fake 5HP" IR compressor from 1990 has a FLA of 15 amps.

So, assuming equal efficiency, this one is a lot closer to a true 5HP than most other units with that motor frame size.

 

[Bert_]

Put an amp meter on it. Diagnose the thing. Don't throw a motor or other parts at it until you know what's wrong.

 

[American Locomotive]

At 21.5A, that's a real 5HP motor.

As mentioned, you need to do the following things:
1) Check the current draw on the motor
2) Measure the voltage after the pressure switch with the compressor running.

 

[DeeKay]

If you do end up finding excessive voltage drop and high amp draw. Check all of your connections from the motor all the way back to your breaker. It sounds like you ran an adequately sized service to the compressor, but a loose connection somewhere can cause the problems you're having.

 

[Citation]

At 21.5A, that's a real 5HP motor.

As mentioned, you need to do the following things:
1) Check the current draw on the motor
2) Measure the voltage after the pressure switch with the compressor running.

Better yet for #2, measure the voltage drop across the switch. It really shouldn't be much. If you are losing power in that switch you will see a voltage drop across one or both of the legs. (ie L1_in to L1_out).

 

[Jswain]

Is the unloader switch working correctly and bleeding off air everytime the compressor shuts off?

I used to have an IR with the same pressure switch and if the adjuster screw that comes factory filled with glue was adjusted too loose or tight and it would sometimes not unload

What pressure does it cut in & out at?

 

[American Locomotive]

Better yet for #2, measure the voltage drop across the switch. It really shouldn't be much. If you are losing power in that switch you will see a voltage drop across one or both of the legs. (ie L1_in to L1_out).

I thought about that, and I think both tests should be done. Measure the drop across the switch, and measure the absolute voltage at the motor with it running. One will test the switch, the other will test the circuit.

 

[strutaeng]

I think those units had a lot of problems with electric motors. I remember reading a lot of guy here having problems with a long time ago. They made a 5HP SL5 and a 3 hp SL3 or something like that?

I would think they are lighter duty units to keep the price low?

You are probably over a bit on the amperage on the last psi before it cut offs. Check with a clamp on ammeter. If that's the case, lower your cut off pressure and maybe that alleviates the problem.

Otherwise it may be the motor. May be worthwhile to look into the used market to see if any good deals fall on your lap...

 

[raynman1972]

Ok, so I got impatient a while back and decided to get a 5hp Baldor, a new pressure switch (a SquareD I think) and a mag starter (also Sqd) and wired it all up. I know I jumped the line with my troubleshooting and did a hail mary, but it worked.

I was using my die grinder last weekend with no regard to how long the compressor was cycling and it never flipped the overheat switch. To be realistic, I think it probably cycled 5-6 times in a row and I repeated this 2-3x over the period of around an hour. No issues.

Very happy and also lucky this worked out

 

[JimH74]

Thanks for giving us an update.

 

[seber]

I think you should have replaced the run capacitor first. A bad run capacitor is cheap and is the main cause of motor overheating.

 

[American Locomotive]

I will agree the "shotgun $600 of parts at it" approach is definitely not what I would have done. But if you are happy, that's all that matters, I guess.

 

[metlmunchr]

Ten years ago those made in Mexico Marathon motors on 5hp IR compressors were burning up during the warranty period and soon thereafter faster than evergreens burning in California. There were tons of pissed off people who found out the mfgr wouldn't stand behind the motor if it was even one week out of warranty when it was a known fact the motors were junk.

The OP just happened to get one that lasted longer than most. Short of buying a new compressor, what the OP did was the smart solution in this particular case. Those motors can't be analyzed or troubleshooted into good health.

Emerson Electric, who also owns the Baldor brand, isn't known for making junk motors in the Marathon line or any of their other brands. I-R, OTOH, becomes more widely known every day for turning out trash under their own name as well as under other brands they've acquired. Chances are, they pressured Emerson into producing a borderline junk motor to meet a price point.

In the current state of things, anyone contemplating the purchase of a new home shop grade compressor would do well to treat the I-R brand as if it doesn't exist. Read multiple reviews of their stuff, and you'll find they may have moved past the motor problems and on to pump problems where they take cheap Chinese pumps and slap their name on them and then run them so far above their rated speed that they become a combination compressor and shop heater. No doubt that'll make for great pump life, but as long as it'll outlast the warranty they could care less.

 

[American Locomotive]

Baldor is owned by ABB, not Emerson.

But yes, it's clear I-R quality took a dive when they started going after big-box-store price points.

 

[DeeKay]

Marathon and Leeson are owned by Regal Beloit. I don't think Emerson has owned a motor brand in a looong time

Yes, IR ***** even on the industrial side of things. I've been in a year long warranty battle trying to get them to replace a cooling fan that's been out of balance since we installed my compressor. Maybe since Gardner Denver bought IR they will improve but I wouldn't hold my breath.

 

[KenC]

In addition to checking the actual draw, use an IR thermometer to check the motor's actual temp when it trips and compare that to the spec.

Wouldn't be the first overtemp switch that was out of tolerance.

Just read to the end and saw that you fired the parts cannon. But it's fixed!