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Compressor safety, it always bears repeating

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Wrench97

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Mine at home is wired with a double pole 30amp switch one side controls the contactor for the compressor the other turs on the outside light next to the man door(detached garage) light is visible from the kitchen, upstairs hallway and bedroom windows, my alarm always tells me if I forgot to turn it off..................................................
 
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Steve_P

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Mine is in my basement and has an on/off switch. A few times I have forgotten to turn it off, and when it kicks on at 3AM, OMG, talk about a heart attack moment :ROFLMAO: Oh, it's a 7.5 HP Quincy, and it is LOUD.
 

PCustoms

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Mine is in my basement and has an on/off switch. A few times I have forgotten to turn it off, and when it kicks on at 3AM, OMG, talk about a heart attack moment :ROFLMAO: Oh, it's a 7.5 HP Quincy, and it is LOUD.
Done that more then once, really gets to dog going....
 

Norcal

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Mine has a service disconnect right next to it & a ball valve on the tank outlet. Set up is about 25 years old, can walk away from the compressor for a month & there's no leak down.
You have a separate service for your compressor? A service disconnect disconnects service entrance conductors, dingbats from the HVAC trade put the loose "service disconnect" sticker that is supplied with safety switches on the disco.
 

ZRX61

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Plastikosmd

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I wish, it probably would still be running!

If only they made the check valve out of the same material that the “made in the USA” sticker(s) were made out of! (And there are no less than 4 on the compressor, lol)






;)
 
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PoorUB

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So let me guess - these self-destroying compressors, they all came from Walmart?
One of mine was a Speedaire, the other was a Porter Cable. One at the shop I worked at was a Sayler Beall, the other I am not certain, but I think it was a Saylor Beall it the other shop too.

Keep in mind, blown, leaking hoses have nothing to do with the brand of compressor.
 

johnre

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Mine is in my basement and has an on/off switch. A few times I have forgotten to turn it off, and when it kicks on at 3AM, OMG, talk about a heart attack moment
That only happened once with me. SWMBO said "fix this". I did.

But thanks to this thread and the good advice given, I have ordered the proper motor start switch for my 240 V 5 HP compressor. I'll have to work out a separate red warning illumination light that indicates it's on, though, as it doesn't have the pilot light feature built into the toggle.
 

JHForman

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I have a note on my shop door that I cant miss when walking out. Im not an electrician, so any circuit I have added myself I turn off before i leave. This would be my welder, and my compressor.
 

racecougar

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Before locking up the shop for the day I always do a complete walk around making sure compressor unplugged, all switches off and the fridge door fully closed! And I thought I was overly paranoid!
I do the same activity: make sure everything is off, no cordless batteries are on a charger, fire watch is complete, all compressed air lines shut off, etc.
 

zmotorsports

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OK, I see it on the spec sheet now. You're correct.

I would say that I am switching it on with no air pressure built up in the tank, and I switch it off with the unit not running. So while I technically am outside the specs, it's not a lot of abuse to this switch, only to the pressure-actuated switch on the compressor. And the latter is built for this.


Here's the single phase equivalent, MS302-DS, which actually is about the same cost as the 1222-7PR that I linked. Except it lacks the red pilot light when "on" feature, but that could be separately added.


^^This is exactly how I did mine.

I should have done it when I built the shop but in the 25 years at the old shop without an issue, I never gave it a second thought when building the new shop to be honest.

I am in the habit of closing the ball valve coming off the compressor each night before locking up. Did that for the 25 years at the old shop and continued the habit here at the new shop. It's as simple as walking into the RV bay and walking up to the compressor and closing the ball valve, plus I get to put eyes on the coach in the RV bay so it's a win/win. ;)

A while back after reading on the forum about guys putting indicator lights on their compressors it got me thinking, so I installed one of the above-mentioned motor starter toggle switches that I wired to interrupt power to the compressor outlet with a paralleled 240 volt pilot light. Now as I walk up to the compressor at closing time, I simply throw the switch and ball valve and rest assured it won't run unexpectantly. If I open the door to the RV bay and see the light on I know I didn't turn the switch off. Granted it's in the next bay but walking in there is such a habit at the end of each day it's no more effort actually.
 

ambenz

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I have a detached heated garage so I have a baby monitor to "listen" to the smoke detector and anything else that creates noise, including the compressor. It is so sensitive, I hear the wind rattle the doors once in a while or the dogs barking across the alley. Found this baby monitor at a garage sale for $10 about 5 years ago. I also have a Swann camera system, so I can log in and see with a smart phone too! It's nice to have that "piece of mind" with 24/7/365 monitoring.
 
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CraigStu

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Most of this depends on usage. Anyone working full time in a shop has a routine so it is pretty easy to work in a little light as an extra warning just in case one forgets. I have a home shop, just an attached 3 car garage. I work sometimes for hours and sometimes for 10 minutes. So I use a timer. My timer shuts off the compressor and also shuts off an electrically operated air valve mounted right on the compressor. The air valve is there because I am lazy and haven't tracked down an air seepage probably from one of the hose reels. So shutting off the air means I always have a full tank even if the pipes have leaked down.
 

johnre

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There are HP-rated motor starting toggle switches. They cost a little more.

But thanks to this thread and the good advice given, I have ordered the proper motor start switch for my 240 V 5 HP compressor.

Received and installed - and thanks to @u2slow , @PCustoms, and others who pointed this issue out and identified a suitable switch series for my 5 HP compressor (well, so-called 5 HP, of course). New switch (left) is massive compared to previous one that was only rated for 1 HP (right):
1709353268106.jpeg

Putting switch in a new, custom size J-box and wiring it only took about half an hour.

But before that could happen, changing out the J-box (the new one is oversized and custom made for this switch, which doesn't fit a standard size) was about six hours - I wanted it mostly recessed so I pulled out my panel, scrolled out the opening, and built a backing brace for it.
1709353588123.jpeg

And the part of this involving removing / reinstalling my compressor panel took 4 hours - it seems I didn't much design it for serviceability and made this very hard to get at from behind (compressor sits above it and air reel in back of it)!
1709353649812.jpeg

Now to get on with the basic premise of this thread - I'll have to add back in a pilot light to indicate it's on!
 
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Monza Harry

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I'm not understanding the problem here, a 5HP compressor should have a magnetic starter, and then the control wire that goes to the pressure switch is interrupted and all that is required is a normal wall switch, you will need to check the voltage though, most will be line voltage, [240V in your case] but could be 120V, 24V, and 24V maybe AC or DC (depending on the starter). Amp draw will be very small like 100 mA @120V. Then buy a switch with the appropriate voltage/Amp. rating, either lighted or not, as desired. 5HP is going to be a minimum of 20A but normally about 25A, a wall switch at that capacity will be huge, and likely not long of this world.
Are you using a magnetic starter? Square D by Schneider Electric L111N 30 Amp 120/240-Volt Single-Pole Indoor Light Duty Fusible Safety Switch with Neutral https://www.amazon.ca/dp/B00002NB3F?tag=atomicindus04-20 This is a 30Amp. to allow for some inrush current disconnect.
Magnetic Electric Motor Starter Control Single Phase Magnetic Starter Motor Control 3 Phase Motor Starter Electric Motor switches 5 Hp Single Phase 220/240v Electric Motor Starter(for Motors) https://www.amazon.ca/dp/B09DT8NP9K?tag=atomicindus04-20
Harry
 
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Briansshop

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Mine has been on for 25yrs. In that time,the press switch stuck and I came home to a loud hot shop. Running with the relief open. Replaced the switch and it's still on. I'm retired now and I'm in the shop everyday so not much reason to turn it off now. :)
 
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johnre

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See if Leviton makes a pilot light kit that can be installed in the switch enclosure.
Unfortunately, no.
Are you using a magnetic starter?
No, it's a manual switch. The reason I said "so-called 5 HP" is that it was produced during the time manufacturers were grossly overstating their HP ratings on air compressors. It's actually rated 7.7 SCFM @90 PSI, it has a NEMA 6-15P power cord, and it's set up on a dedicated 240 V, 20 A circuit - all perfectly kosher per the user manual. By my estimate, it's actually a 2.5 - 3.0 HP motor, not 5 HP.

The reason for having this switch to the dedicated power outlet for the compressor is that the compressor is back of this panel in another room to save floor space and make it quieter. Same reason for bringing out the tank drain and combination regulator; I don't want to take a hike every time I need to turn it on or off or adjust the pressure. But that means I can't see it, hence the need for a warning light that it's on.

I think I'll leave the Leviton J-box alone, as it's sized and set up for only this switch, which is quite large, and I don't like cramming non-standard stuff into such a box - it attracts the scrutiny of home inspectors. What I can do is find a 120 V or 240 V panel mount pilot light and wire it downstream into the dedicated power receptacle (I'm carrying neutral through, so either can work), then bring it out to this panel.
 
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Monza Harry

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Rule of thumb for HP is ~5A @ 240V is 1 HP so 15A (+/-) @240V is ~3 HP, that is doable with a HD wall type switch [as you are using/sourced). And illuminated/pilot lighted at those amps and voltage will get hard/expensive to find! My 5HP is 26.4 FLA as an example. Harry
 

johnre

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And illuminated/pilot lighted at those amps and voltage will get hard/expensive to find!
The current rating on the motor has little bearing on pilot light specs; it's only about the voltage. And I just found this on Amazon; since it's 12 V DC on the LED, I can just mount the power supply within the receptacle J-box to meet code, and then use low voltage wiring to the LED on the panel. And since the primary range on the power supply is 100V - 240 VAC, I can run it at 240 V AC and don't need to bother breaking out neutral to get 120 V AC.

1709460130252.png
 
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Beerhippie

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I guess we're playing in different leagues when it comes to compressors.

53568258435_fa40b0dd48_b.jpg

That "vintage" 5 hp, 80 gallon DeVilbiss compressor use to be the primary for the brewery. We use a lot of air-actuated valves to control cooling systems for our fermenters, so that beast was plugged in 24/7/52. It used to occasionally pop a breaker on start-up until I replaced the unloader valve. Fixed that. It would shake the entire shop when running and sounded like a natural disaster of the first degree--but it ran reliably for us for fifteen years.

It's since been supplanted by a nice IR rotary-vane, also 5 hp and 80 gal. The DeVilbiss is now a back-up.

Duty cycle should have nothing--absolutely nothing--to do with whether the compressor is turned on or not. You all need to do a little more preventative maintenance if you think it does. If my compressors blow out, it could compromise 10s of K-bucks of product in our fermenters.

The best way to reduce the duty cycle of a compressor is to size it for the job--if you're drawing so much air it's running continuously, you'll be shopping for a new comp very soon. Air reservoir capacity will also influence duty cycle--too small and you're running too frequently. Both of those compressor tanks are tied together, so I have 160 gallon of comp air, plus "surge tanks" at high consumption, short demand equipment.

If you're looking for continuous production of LOTS of air, you're looking for a blower, not a compressor.
 

johnre

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This is how I mounted my switch that controls the outlet for my Quincy QT-5 compressor along with the pilot light.
While that manual switch looks pretty large, I see it's in a standard size J-box, so I know it's not the Leviton MS302 (post #64) that I ended up installing. Mind telling me what you used here?

And that is a good bright pilot light you found there!
 

zmotorsports

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While that manual switch looks pretty large, I see it's in a standard size J-box, so I know it's not the Leviton MS302 (post #64) that I ended up installing. Mind telling me what you used here?

And that is a good bright pilot light you found there!

It's a standard size J-box but the deep version.

The switch was a Hubbel HBL7842D (40-amp 2-pole) switch. I had to "message" the box slightly for fitment and usage of a standard stainless steel cover in which I drilled for the pilot light.

Here's the switch.

Here is the 18mm pilot light.
 

johnre

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The switch was a Hubbel HBL7842D (40-amp 2-pole) switch.
Thanks for the links; I see it's oversize just like the Leviton. They also sell a non-standard enclosure for it, but there would be no room for the pilot had you gone this way.

And in hindsight I'm glad I used this type of box, even if I have to work out something different for the pilot light. I want the lockout feature on the starter switch for all of my power tools, as there are now two younger grandsons in the picture. Like anything else in the shop of this nature, air compressor starters should be lockable.
 
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zmotorsports

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Thanks for the links; I see it's oversize just like the Leviton. They also sell a non-standard enclosure for it, but there would be no room for he pilot had you gone this way.

And in hindsight I'm glad I used this type of box, even if I have to work out something different for the pilot light. I want the lockout feature on the starter switch for all of my power tools, as there are now two younger grandsons in the picture. Like anything else in the shop of this nature, air compressor starters should be lockable.

Agreed. The pilot light is why I opted to go the route I did. I guess I could have mounted it in a separate box but I already had the deep double gang J-box so thought I'll "tweak" it a bit and if it worked great, if not then I wasn't out anything and would have to go to another pilot light arrangement.

If you were looking for a lockout feature then you definitely went the right route. That looks nice and clean as well. Great job.
 
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johnre

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For anyone in the thread using a standard J-box and cover plate - I now see this is available for standard wallplates, and it appears it might accommodate the oversize toggle on a motor start switch. It's not high security, of course, as it can be defeated with a screwdriver. But the Leviton cover is almost as weak security-wise. And at least these offer some level of protection from someone casually throwing the switch on and having access to compressed air, and it's out of the way when you don't need to lock it.

Although whoever set up the photo shoot apparently doesn't really understand which way it would normally be locked!

1709743027055.png
 
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johnre

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Um .... I think it's going to be bright enough, yes?

All using only 0.95 W - glad I didn't go any higher. This isn't a head-on shot of it; that washes out the image too much. But it's still viewable almost to 90 degrees off-axis.

It looks like the small power supply can fit into the back of my existing deep single-wide J-box that houses the NEMA 6-20 receptacle.

I'd recommend this arrangement, as the low voltage 12 V wiring on the LED allows you to mount it anywhere it's most noticed, which may not be at the switch location.

1710033650331.png 1710033751952.png
 
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