Solberg filter/silencer causing compressor to trip circuit breaker?

[lslo]

Hello, I’m a new member here, first post. But long time lurker. Hoping to help/advice.

I’m reaching out to this community for someone to educate me on why the Solberg filter/silencer I replaced the stock filter with is causing my compressor to trip the circuit breaker?

It’s my inexpensive mastercraft 20 gal compressor, Oil-Free Portable Vertical Air Compressor, 135 PSI, 2HP, Product number 0111820. It’s just plugged into a regular 110v outlet, I think 15 amp. Has worked fine up until now.

The Solberg filter silencer is FS-06-50, and now it trips the circuit breaker after a few seconds of what sounds like lugging, but I honestly don’t know. If I remove it and the stock filter, it also trips the breaker. However, once I put the stock filter back on, it operates normally without tripping the breaker.

Any ideas what’s going on? Does it have something to do with the max flow through the Solberg? Or something entirely unrelated?

Any thoughts or suggestions would be very much appreciated!

 

[pcmeiners]

Believe an exorcism is needed; they ain't cheap nowadays

 

[PBCampbell]

Take the Solberg off and use the original to see if that is the problem.
Actually upon reading again, maybe you did that?

 

[RTM]

The filter is rated at 12 SCFM, that's standard cubic feet per minute. What is your compressor sucking

SCFM are rated at ambient pressure, correct?

 

[lslo]

The filter is rated at 12 SCFM, that's standard cubic feet per minute. What is your compressor sucking

SCFM are rated at ambient pressure, correct?

The specs I’ve read for my model compressor:

Rated Air Flow: 6.2 CFM @ 40 PSI, 5.2 CFM @ 90 PSI

Is it part of the job of the filter to limit the air flow? My understanding of this is limited.

 

[LXCam]

No that’s not part of its job. It can’t flow enough and the compressor is working too hard on restart. Another words, you’re starving it for air.

 

[lslo]

Take the Solberg off and use the original to see if that is the problem.
Actually upon reading again, maybe you did that?

Yes, it still works just fine with the original filter. So I could just stick with it. I was just hoping to reduce the sound a little with the Solberg, and so I’m trying to understand why it would cause it to overload the circuit.

 

[GeoBruin]

The filter is rated at 12 SCFM, that's standard cubic feet per minute. What is your compressor sucking

SCFM are rated at ambient pressure, correct?

It's definitely making less than 12 cfm if it's being run on a 120 15 amp breaker.

Regardless, OP said they tested without any filter, and it blew the breaker. Theoretically, no filter at all should be the maximum amount of throughput possible on the intake side, so for my money there's something else going on.

In any case, it sounds like this compressor is bumping up close to the 15 amp breaker's limit. Is there a 20 amp breaker available? Do you have a clamp meter you can use to test the current draw with the various filter options? Did you inspect the inside of the solberg filter to make sure a piece of packaging didn't get sucked up inside?

 

[The Cobbler]

is there any thing blocking the passage of the new filter? that's the only thing that makes sense .
I once bought a compressor really cheap because it was returned by a contractor. wouldn't build pressure.
the reason it wouldn't build pressure was because the air filter was in the box, still wrapped in plastic , with a plastic plug in the intake . go figure

 

[lslo]

is there any thing blocking the passage of the new filter? that's the only thing that makes sense .
I once bought a compressor really cheap because it was returned by a contractor. wouldn't build pressure.
the reason it wouldn't build pressure was because the air filter was in the box, still wrapped in plastic , with a plastic plug in the intake . go figure

So I just opened up the new filter. I don’t see anything that is clearly obstructing. I’ll have to take a closer look at the compressor side when I get a chance later.

 

[Zebu Fellenz]

If I'm understanding correctly:

Solberg filter - trips the breaker
No filter - trips the breaker
Factory filter - does not trip the breaker

If I have this right I cannot see how the Solberg filter is the problem as you have even less restriction running without a filter.

15A or 20A breaker? Is the tank pressurized or empty when you started the compressor with various filters, no filter?

 

[lslo]

Ok, I have an update. It has me just as confused.

I reinstalled the Solberg. I turned on the compressor. It started up with a low grumble, kind of like the sound of a lugging engine. Now instead of letting it trip the breaker like previous times, for some reason I just tried putting my finger over the air inlet hole of the Solberg. I just covered it partially, and the pitch of the sound went higher. And the compressor did not trip the breaker; it kept running. After perhaps 10 seconds, I could move my obstructing finger away completely and the compressor continued to run without tripping. If I turned it off and turned it back on again with my finger off the hole, it’d trip the circuit again.

I don’t know how to make sense of it, but it seems like I needed to INCREASE the air flow obstruction, at least momentarily, to keep the compressor from drawing too much current.

Does this make sense you any of you?

Thanks for all the suggestions and ideas so far.

 

[Shoreline_]

I'm no engineer by trade. But I did goto school for fluid physics. It takes less power to move no air (plugged inlet) than to move air. It's why when you put your hand over a vacuum cleaner, the rpm's increase. To be honest I don't think your inlet filter type has anything to do with the breaker tripping.

The way I figure, you have a stuck valve.

 

[timgunn1962]

Old filter restricting airflow and limiting the volume of air drawn in, therefore peak pressure at tdc is lower, the compressor isn't working as hard and doesn't trip?

If so, either the old filter was restrictive by design, or there's some other fault the filter was suppressing. Are the motor and pulleys original?

 

[lslo]

Another discovery just now. I looked at my stock filter more closely. It looks like there is some sort of metal liner welded inside the 0.5” NPT screw on part, making the internal diameter smaller than Solberg’s. I wonder if this is a significant factor.

 

[lslo]

Old filter restricting airflow and limiting the volume of air drawn in, therefore peak pressure at tdc is lower, the compressor isn't working as hard and doesn't trip?

If so, either the old filter was restrictive by design, or there's some other fault the filter was suppressing. Are the motor and pulleys original?

This is starting to make some sense to me. I think now that the original filter was restrictive by design. I can’t think of another reason to go to the trouble of welding in a piece to reduce the internal diameter of the air flow passage.

 

[The Cobbler]

the reed valves have more restriction than a filter housing would I would think.

 

[finn]

The “restrictor” in the original filter is a noise control device, not unlike used on some turbochargers.

My vote is a leaking check valve allowing tank pressure to enter the cylinder. The motor isn’t powerful enough to work against the trapped pressure when starting from zero rpm so current draw shoots up and trips the breaker.

The filter observations aren’t causal. Repeat your experiment a dozen times and see what happens.

 

[RTM]

Our try the various tests w the tank empty.

 

[mike93lx]

I know you are new here, but you'll soon learn that the right answer is a new, 5hp 60 gal unit

 

[Speed-Racer]

I know you are new here, but you'll soon learn that the right answer is a new, 5hp 60 gal unit

Or 5hp 80 gallon unit.

 

[finn]

I know you are new here, but you'll soon learn that the right answer is a new, 5hp 60 gal unit

80 gallon

 

[lslo]

Looks like I have some more experimenting to do. I’ll update if there’s anything revealing.

Thanks for all the suggestions and insight.

 

[nadogail]

Welcome to the Forum from Southwestern California.

Is your 120 Volt Compressor operating on a dedicated circuit? or is it sharing the 15 Amp breaker with other loads?

 

[mike93lx]

80 gallon

I was trying to be reasonable.

 

[American Locomotive]

As someone else mentioned, the load on a compressor is proportional to how much air is flowing through it. If you completely restrict the inlet of a piston-type air compressor, it will essentially be unloaded.

Compressors normally have something called an unloader, that vents the pressure in the discharge (pressure side) of the line. This allows the compressor to get up to speed before experiencing load. It's possible the unloader mechanism on your compressor is not working correctly. Usually you can identify this as a second small diameter tube going to the pressure switch coming from the discharge pipe off the compressor pump.

The parts diagram I looked up for your compressor shows that it has an unloader pipe going to the pressure switch. You can figure out if this is working by flipping the lever to turn the compressor off while it's running. You should hear a "psssssshhh" of air coming out of the pressure switch.

It's also possible the motor just doesn't really have enough grunt, so they engineered a restriction into the intake to reduce the load a bit. Is the compressor plugged into an outlet, or into a cord?

 

[Jswain]

I was trying to be reasonable.

5hp 80g used to be the reasonable around here....now it's getting closer to 7.5hp I see

 

[finn]

5hp 80g used to be the reasonable around here....now it's getting closer to 7.5hp I see

I passed on a 10 hp with a 120, I think, gallon horizontal tank for $275 a month ago. I wasn’t going to tell anyone that I passed on it for fear of being drummed out of the corps.

 

[The Tool Tyrant]

Does anyone here Honestly believe that anyone would design and build a compressor that required the intake to be restrictive so it could be used on a 15 amp breaker? I for one, think not.

My vote is that restricting the intake is just masking the real issue. I'd check the condition of the valves along with checking that the check valve is not gummed up causing the pump to work harder to open it.

 

[Jswain]

Does anyone here Honestly believe that anyone would design and build a compressor that required the intake to be restrictive so it could be used on a 15 amp breaker? I for one, think not.

My vote is that restricting the intake is just masking the real issue. I'd check the condition of the valves along with checking that the check valve is not gummed up causing the pump to work harder to open it.

Bingo

 

[American Locomotive]

Does anyone here Honestly believe that anyone would design and build a compressor that required the intake to be restrictive so it could be used on a 15 amp breaker? I for one, think not.

Absolutely. You see that sort of thing all the time with mechanical devices. I've seen devices with blowers/fans before that had restricted inlets or outlets, and removing the restriction prevents the fan motor from spinning up to full speed. It will just sit there lugging until it either burns up or trips on overheat.

I'm not saying that is absolutely the case here (which is why I told OP to check that the unloader, which his device has, is working correctly), but I could believe it. Cheap manufacturer designs product, finds that in certain cases it cannot start reliably, but they've already sent everything to production. Quick, spin up a new air filter with a slight restriction. Problem solved. Ship it.

 

[u3b3rg33k]

I'm no engineer by trade. But I did goto school for fluid physics. It takes less power to move no air (plugged inlet) than to move air. It's why when you put your hand over a vacuum cleaner, the rpm's increase. To be honest I don't think your inlet filter type has anything to do with the breaker tripping.

The way I figure, you have a stuck valve.

these are very different things, and shouldn't be likened to each other. most vacuum motors are universal motors, which don't care about line frequency, and they're driving a fan, not a positive displacement pump (piston pump). fan power is near zero at low RPM, and increases non-linearly with increases in speed.

a piston pump's max load should be at max PSI just prior to shutoff, and cheap (read: what comes on big box store plug in compressors) unloaders do nothing more than check valve the tank and bleed off line pressure so that the pump can start moving. not having a filter/better filter on a piston pump SHOULD not be a reason for a breaker trip.

As someone else mentioned, the load on a compressor is proportional to how much air is flowing through it. If you completely restrict the inlet of a piston-type air compressor, it will essentially be unloaded.

Compressors normally have something called an unloader, that vents the pressure in the discharge (pressure side) of the line. This allows the compressor to get up to speed before experiencing load. It's possible the unloader mechanism on your compressor is not working correctly. Usually you can identify this as a second small diameter tube going to the pressure switch coming from the discharge pipe off the compressor pump.

The parts diagram I looked up for your compressor shows that it has an unloader pipe going to the pressure switch. You can figure out if this is working by flipping the lever to turn the compressor off while it's running. You should hear a "psssssshhh" of air coming out of the pressure switch.

It's also possible the motor just doesn't really have enough grunt, so they engineered a restriction into the intake to reduce the load a bit. Is the compressor plugged into an outlet, or into a cord?

please see above comments on piston pumps.

Restricting the inlet on a positive displacement pump will increase load in a free air situation (no tank/discharge pressure, restricted vs unrestricted inlet). the pump goes from virtually no load on the downstroke to attempting to pull vacuum. or looked at another way, you go from pumping 0 psi on start to pumping 15PSI discharge pressure (1 ATM) on restricting the inlet. that's added load however you want to do the math.

 

[American Locomotive]

Restricting the inlet on a positive displacement pump will increase load in a free air situation (no tank/discharge pressure, restricted vs unrestricted inlet). the pump goes from virtually no load on the downstroke to attempting to pull vacuum. or looked at another way, you go from pumping 0 psi on start to pumping 15PSI discharge pressure (1 ATM) on restricting the inlet. that's added load however you want to do the math.

That is not the case for the majority of piston air compressors. This is because piston compressors have valves actuated by the movement of air - not a camshaft or other means. When you block the intake completely, there is no air to be pumped. A vacuum gets created, but it simply pulls the piston back up. It just acts like an air spring. Try it. I've messed around with my piston compressors, and if you block the intake, they basically freewheel.

 

[u3b3rg33k]

I don't think the type of valve matters. I know what you're talking about though, I've turned off my ignition on the freeway. open the throttle, engine becomes an air brake. close the throttle, less engine braking.

the motor still has to overcome that spring force (1ATM pushing the piston back up). I haven't heard the sound to be sure if OP's compressor is actually turning over. Personally I'd check the capacitor, and start switch if it has one. My cheap oilfree compressor came with a solberg silencer (or a nice knockoff), and it starts just fine if I completely unscrew it from the head.

 

[Shoreline_]

these are very different things, and shouldn't be likened to each other. most vacuum motors are universal motors, which don't care about line frequency, and they're driving a fan, not a positive displacement pump (piston pump). fan power is near zero at low RPM, and increases non-linearly with increases in speed.

a piston pump's max load should be at max PSI just prior to shutoff, and cheap (read: what comes on big box store plug in compressors) unloaders do nothing more than check valve the tank and bleed off line pressure so that the pump can start moving. not having a filter/better filter on a piston pump SHOULD not be a reason for a breaker trip.

please see above comments on piston pumps.

Restricting the inlet on a positive displacement pump will increase load in a free air situation (no tank/discharge pressure, restricted vs unrestricted inlet). the pump goes from virtually no load on the downstroke to attempting to pull vacuum. or looked at another way, you go from pumping 0 psi on start to pumping 15PSI discharge pressure (1 ATM) on restricting the inlet. that's added load however you want to do the math.

I understand where you went wrong. It was a very long winded reply (mentioning the type of electric motor means nothing, work is work) but you're still wrong lol. It seems a classic garage journal "I'm really smart" reply. If the pressure is near 0 abs in the chamber the only resistance is in the crankcase on the other side of the piston. The area of the underside is slightly more than the top because of the features of the casting. The crankcase is atm or slightly below depends on how it's vented. Either way it's not enough to trip the breaker. And it's definitely not enough to be a measurable difference. But you know what is a large measurable difference in current? Wide open inlet port vs sticking your finger over it.

Either way. oP - Just replace the check valve like everyone else said. You probably sucked in a piece of **** changing the filter over and now it's stuck in the tank check valve. I don't think it requires the garage journal scientists to fix.

 

[u3b3rg33k]

I understand where you went wrong. It was a very long winded reply (mentioning the type of electric motor means nothing, work is work) but you're still wrong lol. It seems a classic garage journal "I'm really smart" reply. If the pressure is near 0 abs in the chamber the only resistance is in the crankcase on the other side of the piston. The area of the underside is slightly more than the top because of the features of the casting. The crankcase is atm or slightly below depends on how it's vented. Either way it's not enough to trip the breaker. And it's definitely not enough to be a measurable difference. But you know what is a large measurable difference in current? Wide open inlet port vs sticking your finger over it.

15 psi shouldn't be enough to trip the breaker on a compressor intended for 100psi+ operation, I agree. it probably shouldn't be enough to stop it from starting before the breaker trips, either, which points to another issue being present.

the type of motor absolutely matters. comparing a motor on a fan that has no start capacitors, start windings or speed control against an induction motor on a compressor is both pointless and confusing to the issue.

 

[RTM]

Does anyone here Honestly believe that anyone would design and build a compressor that required the intake to be restrictive so it could be used on a 15 amp breaker? I for one, think not.

I'm with AmLocomotive, I don't know that they designed it, vs threw off the shelf components together in their design. Being a private label for MasterCraft, and inexpensive, it may not have had a rigorous design review process that someone like Sullair or Ingersoll Rand may have done. Don't want to waste too many engineering $$ on a cheap product.

 

[u3b3rg33k]

Does anyone here Honestly believe that anyone would design and build a compressor that required the intake to be restrictive so it could be used on a 15 amp breaker? I for one, think not.

My vote is that restricting the intake is just masking the real issue. I'd check the condition of the valves along with checking that the check valve is not gummed up causing the pump to work harder to open it.

likely not applicable here, but I have seen fouled up aftercoolers (pre tank pressure sensor) causing head pressure relief valves to blow open "for no reason" while tank pressure is below target. lots of head scratching solved by measuring a few simple things.

 

[u3b3rg33k]

That is not the case for the majority of piston air compressors. This is because piston compressors have valves actuated by the movement of air - not a camshaft or other means. When you block the intake completely, there is no air to be pumped. A vacuum gets created, but it simply pulls the piston back up. It just acts like an air spring. Try it. I've messed around with my piston compressors, and if you block the intake, they basically freewheel.

I think i'm being misunderstood. the "spring" energy on a running compressor nets out. on one you're trying to start (not turning) it takes more torque to rotate. still unsure if the OPs compressor is actually finishing a single revolution.

 

[lslo]

Thanks all. I’ll try to report back when I find something, if people are still interested. But I’m going to have to read through the above posts a few times, when the kids aren’t screaming, to make sure I understand the suggestions. Coming from very limited knowledge.