Wiring Air Compressor to Magnetic Switch & Pressure Switch

[d4herb]

Hows it going. I am trying to wire a mag switch and psi switch to my air compressor and am feeling a little retarded.Ya think with all the pics and diagrams I could figure this **** out.Hopefully I didn't F*up anything with trial and error. Any help in getting all these guys wired would be appreciated, Thank you.

Pics are worth a thousand words:

Compressor: American IMC - Belaire 80g (...I think) air compressor

Motor: Magnetek 5.0hp 220v 1 phase

Magnetic switch: 5 HP Magnetic Switch 220v Single-Phase
http://www.grizzly.com/products/5-HP-Magnetic-Switch-Single-hase/T20551

Pressure switch:

 

[pattenp]

Here’s my stab at it.

Line in (2 hots) to Mag L1 & L3. Mag 1/2(T1) & 5/6(T3) to Motor.
Pressure L1 to Mag L1. Pressure T1 to Mag NC 15 or that may be NO 13. That's where I get confused.

I guess if this is wrong the worst is it won't start.

 

[Steevo]

I downloaded the manual from Grizzly to see if there was any additional useful information there. Not so much.
But by studying the way the mag switch works, and looking at the diagram, it appears that when the field coil side of the switch gets 240v power to it via terminals A and B it energizes the switch and allows power to flow across the mag switch to the thermal relay, through the thermal relay and to the motor connections on 1/2 and 5/6.
This being the case, breaking the path between terminal 14 and terminal B, which is shown as a short black wire in the diagram, would be a logical place where you could insert a pressure switch connection to enable/disable that power to the coil, allowing the pressure switch to control the mag switch whenever the system is energized by having pressed the green button.
I am surprised that they haven't mentioned in the manual where to tie in the pressure switch as a control in the field coil energizer circuit.

 

[jb3179]

I hate to break it to you but your compressor does not require a mag starter. Your motor already has internal overload protection (the red button on the back) and the pressure switch you have is rated (22 amps if I am reading the picture right) to handle the load of the motor. Why do you want to add the mag starter? The starter serves 2 purposes to pick up the motor load and to protect the motor from overload. you already had this covered with the factory components in place. If you need a mag starter for the sake of having it wire it like this: Take 2 wires from the line side of the mag starter (either 220v or 120 v depending on the coil rating in the mag starter) over to the line side of the pressure switch then from the load side of the pressure switch back to the coil on the mag starter. Now your pressure switch is operating at what we call pilot duty, it is only carrying the load of the magnet in the starter and the mag contacts are carrying the motor load. be sure you have the overload in the mag starter set to the FLA of the motor.

 

[pattenp]

I didn't pay any attention that the motor has overload protection. Dump the mag starter, makes things a lot simpler.

 

[-JP]

I hate to break it to you but your compressor does not require a mag starter. Your motor already has internal overload protection (the red button on the back) and the pressure switch you have is rated (22 amps if I am reading the picture right) to handle the load of the motor. Why do you want to add the mag starter?

I hate to break it back to you jb3179 but d4herb does need to use the magnetic starter because the pressure switch is NOT rated for 5HP.

You really need to do your research before giving out information that would cause equipment failure and possibly start a fire.

Yes the pressure switch has a label that indicates 22 amperes but there is no indication at all for maximum horsepower. a quick search in my literature shows this switch is only rated for 3HP MAX at 240V 1-Phase.

This is why Bel-Air provided the starter from the factory. Common sense shows most manufacturers do not provide equipment that is not required in order to be as profitable and price competitive as possible.

JP

 

[pattenp]

I don't know why, but I had the impression that the OP was adding the mag starter. I didn't realize it was original equipment. I need to watch out with whom I agree.

I hate to break it back to you jb3179 but d4herb does need to use the magnetic starter because the pressure switch is NOT rated for 5HP.

You really need to do your research before giving out information that would cause equipment failure and possibly start a fire.

Yes the pressure switch has a label that indicates 22 amperes but there is no indication at all for maximum horsepower. a quick search in my literature shows this switch is only rated for 3HP MAX at 240V 1-Phase.

This is why Bel-Air provided the starter from the factory. Common sense shows most manufacturers do not provide equipment that is not required in order to be as profitable and price competitive as possible.

JP

 

[d4herb]

First off, want to say thanks for the help. Some forums you post a question and see it getting closer and closer to page 2 w/o any responses...so thanks again.

Actually the compressor was originally wired to just the pressure switch (for a few years now) BUT to turn it on and off I would manually have to either unplug it (wear and tear on plug) or flip the breaker at the panel (wear and tear on breaker).

Decided to buy the magnetic switch just for the ease of an on and off button.

Will try some of the wiring suggestion tomorrow after work and will post back to let you guys know how I made out.Take it easy.

BTW Just one more quick thing...bought the compressor used from a friend years ago and he either lost/misplaced a few items.....I actually had to buy the pressure switch, hire someone to wire, trying to save a few bucks this time around, now trying to wire (myself) the mag switch into the mix.

Mag switch is less then a week old, bought it from grizzly for around 80 bucks.
Made sure that it did match up with the motor though..220v-single phase-5hp....now just making everything play nice together.

 

[superdel]

First, the pressure switch will be adequate. A 5 hp motor at 240 VAC will draw nowhere near the rated 22 amps. Besides the PS is used on the control side of the circuit anyway.

Second, you have to have a start and stop button external to the starter. Is it on the cover of the starter? The start pushbutton will push in on the left hand side in the middle of the starter and the stop button will push in on the that little button on the right? If this is the case as I suspect, you have to take the jumpers out of there and start from scratch. The stop has to be the first in line then the start circuit, then the PS, then the coil, then the OL circuit. Let me know where the push buttons are and I will draw the circuit for you (really simple to wire), scan it and send it to you. The 2 things that will stop the compressor from running besides turning the feed breaker off or unplugging, will be pushing the stop button or coming up to pressure.

 

[Aceman]

First, the pressure switch will be adequate. A 5 hp motor at 240 VAC will draw nowhere near the rated 22 amps. Besides the PS is used on the control side of the circuit anyway.

I wouldn't count on that. He already has the starter, why not use it?

If it was mine, I'd use the starter but pull the overloads off the bottom of it. The motor already has thermal overload protection built in, so you don't need it on the starter. Use the pressure switch to fire the coil, buy a PLASTIC on/off switch and mount it in the side of your starter enclosure. You don't want something like a metal toggle switch mounted in a plastic enclosure because it wouldn't be grounded, since it's isolated.

If you pull the overloads out of the enclosure, you'd have more room for a switch to mount on the side of the box. Something like this:

http://www.grainger.com/Grainger/POWER-FIRST-Rocker-Switch-2VLR2?Pid=search

Wire the pressure switch and the on/off switch so they are in series with each other.

 

[buzz4041]

From the diagram you have a on/off switch on the right side. That switch has to close to enable the control circuit to work. If you remove the jumper between 14 and B and then wire your pressure switch from 14 and return to B your done. This will put it in series with on/off switch just as Aceman said.

 

[d4herb]

The ON/OFF switch is located on the right side, On (green) upper right and Off (red) is bottom right (actual button pushes down on the red deal sticking out)

The switch does have a cover with 2 buttons (ON/Green and OFF/Red as described above..just took it off so the wiring could be seen....damn just typed this a link would be easier, here is what it looks like with the cover on:

http://www.grizzly.com/products/5-HP-Magnetic-Switch-Single-Phase/T20551

Thanks again for your time.

 

[buzz4041]

Herb do just like I posted above and your done.

 

[superdel]

Buzz is correct. I will put this caveat on it. If you use it like that, each time the compressor reaches pressure, it will shut off. So when you want to make pressure, you have to press the start button. The reason I said to take all the jumpers off and start from scratch is to set it up with an on/off switch. This way, you come in to the shop and turn the switch to on, and the compressor will run off the pressure switch all day. If you are good with a one shot start, then do as Buzz says. The other way is simple to wire also, but will require an external on/off switch. I was not familiar with this starter, but they are all basically the same. I run everything with an external on/off switch as well as an emergency stop.
If you decide to go with the external switch, I will draw it out and send it to you. If you go with Buzz, just make sure you use the NC contacts on the pressure switch so it opens the circuit when it comes up to pressure.
Good Luck and let us know how you make out.

 

[d4herb]

Just had to give you guys an update.

It was an 80 buck lesson in hooking up mag switches.

Before posting decided to set up an appointment with an electrician and he confirmed what I suspected...switch is fried.He only charged me 40 bucks and was here for over an hour.

Also did a search and found nothing via google about this:

When trying to start a mag switch it just rumbles and vibrates...it is shot.Just FYI.

When the electrician was here he hooked it up in the correct order so, just going to buy the same exact one and swap it out.

Thank you all again for your help.

BTW When I get the new one will post pics of it hooked up just for reference if anyone else comes across this issue in the future..between the pics and the other ways that you guys suggested to hook it up (more then one way to skin a cat) hopefully the post/topic will be helpful to others.Take it easy.

 

[d4herb]

SOME pics of the COMPLETED wiring so now one else fries the switch in the future, just to recap:

-5hp 220v motor, d-square pressure switch, and grizzly (grizzly.com?) bought magnetic switch all wired together...hope the pics help.

 

[TOOL MASTER]

i just leave mine on....has been on for 16 years now..lol

 

['04 Cummins]

Wait, do you have the incoming power going to the starter, then to the pressure switch, then to the motor? That's what it looks like to me, sorry if not.

If you have done it that way, you've defeated the entire purpose of installing a starter. The starter's coil needs to be driven by the pressure switch and the motor's current shouldn't go through the pressure switch. The purpose of using a starter is because the pressure switch isn't rated to handle the motor's current, so you use the starter contacts to handle the current, and the pressure switch turns the starter coil on and off. An air compressor isn't really the right application for a starter with push-button control.

 

[d4herb]

Hook up is 220v wall power>psi switch>mag switch>motor...think sounds/looks right. Hired an electrician in the end so what you see in the latest pics are his work, just copied it when I installed the NEW mag switch...I know my limitations.

I use to turn the compressor ON/OFF from the breaker box...lots of wear and tear now, I can actually hear a difference (maybe in my mind sounds much smoother on start up...pressure switch kicks on when psi gets @ around <100psi and adjusted to kick off @ around 150psi.

happy as hell it WORKS..lesson learned for me is don't f**k with 220v...hook 110v wrong...don't work no prob...re-wire, 220v FRIES parts if not hooked up correctly the 1st go ($90+ dollar lesson=1st mag switch)....Sorry got off on a tangent.

BTW to the one poster..would leave it ON forever BUT don't like the damn thing kickin on a 3 in the morn....kind startles the **** outta ya. ;P

 

[d4herb]

An air compressor isn't really the right application for a starter with push-button control.

Maybe so, but does it not look DAMN ****

 

[-JP]

d4herb, now that you have shown the pics of the way your "electrician" wired up this motor, I have to agree with 04 Cummins and say this installation is all screwed up.

You went through all this effort and bought new parts but applied them in all the wrong ways and provide yourself none of the benefits of the intended purpose for each device.

 

[DoyleDee]

Easy now.... let's don't get our feathers all ruffled up. The Op is happy and that is what matters.. so what if the components aren't used as their intended purpose but work like the Op wants. I would have done something completely different.... but it works...

 

[buzz4041]

Glad to hear it is working for you.

 

[d4herb]

-JP I will give ya the electricians phone number and ya can kick his *** for me...I tried hooking it up myself...fffdd it up, you hire someone and expect for them to do things proper. I don't know.

 

[buzz4041]

D4herb it is hard to get a residential electrician that really knows anything about motor controls. It works as stated and that contactor will last forever that way. Not sure about the PS though.