I picked up a 5hp, 220v, IR T-30 compressor. Running it direct off the 220 it seems fine. In order for the pressure cut off to work, I need a magnetic switch. Grainger wants $500.00 and my local supply houses don't seem to know what I am talking about (maybe I'm not explaining it right). Can anyone recommend a source?
Are you talking about a magnetic starter? They are used when you don't want to pass the current through the pressure switch. Usually that is a three phase application. With a 5 HP 220V motor you should be able to use a regular pressure switch and break the 220V through the switch.
Right "magnetic starter". This is not a "homeowners" unit, I am trying to wire it the way it was originally. There is a pressure switch, but it has armored cable coming out of it. I figured that would lead to a magnetic starter.
Will that do what I am looking for? Seems to me I want off at 120 psi, on at about 80 psi. Just using it for bead blasting. Sorry, never had one that you didn't just plug in.
That's how mine is set up, and it seems to be working fine (been using it for 18 years like this). I got a magnetic switch thing with the compressor from the previous owner, but never installed it, and he never did either.
Well, I guess I better look into it. There is nothing the The H.A.M.B. doesn't know, Google watch out.
OK, been looking at pressure switches on line at Graingers. For 1 Phase - 230V, they seem to quit at 3 hp. Mine is 5hp, am I in trouble?
That "magnetic switch" is called an electromechanical contactor, you really don't need it for single phase 220. You should be able to get a 5 HP pressure switch rated for 220 single phase. It's actually a " mechanical contactor " working off of tank pressure. Not to confuse but if you had a electromechanical contactor running your compressor, there is a light duty 110 pressure switch in the compressor tank ( a mechanical contactor) controlling the electromechanical contactor.
So, you say, just keep looking. Not encouraged, when I didn't know what I was looking for, I looked at a lot of pressure switches. Don't recall any rated for 5hp on 220v.
Don't forget that the contactor/starter usually contains your motor overloads. Your breaker or fuses typically are only for short circuit protection. Unless the motor has built in thermal overloads which most 5 horse motors won't.
5 HP is a lot to ask of any pressure switch I have seen. A good magnetic starter/contactor for a 5 HP motor isn't cheap, but there is cheap new ones out there, and plenty of used stuff floating around as well. If the unit will be used much, make sure that replacement contacts are available for whatever switch you get because they don't last forever.
I'd do some looking around at the Garage Journal Bulletinboard, lots of good compressor info there. Also brought to you by Ryan. Dave
I've got a Grainger's 5 hp 2 stage compressor, came with a magnetic starter, and it is single phase. It went out a few months ago, and I bit the bullet and bought a new starter...yeah, they are damned expensive! In fact, I'm still workingwith my spare smaller compressor, because I installed the switch and it still dosn't work. The pressure switch is good, closed, as there is no pressure in the tank, but I believe only one contact is being made in the starter. Any hints on how to adjust it? Oh...I think you're going to have to put the right mag starter on yours. Maybe a local compressor repair shop can hook you up with a good used one.
I tried to get around it but wound up buying a new one also. Around $450 if I remember correctly. It hurts but now I feel its done right.
You can use a SQAURE D 9013 pressure switch to run the machine, grainger sells it, there is more than one type of 9013 switch though. The one you want will have the blow down on it with the armature to start and stop the unit. You can also get cheaper versions of that switch at tractor supply. You do not have to use the mag starter to run your machine.
Whatever switches the motor needs to be rated for the motor's current draw and initial current inrush. Inrush is a LOT on a 5 HP motor. That's what you need to do the job properly. What you can get away with, an how long you can get away with it is another matter. If you want to do this right, know what the rating of the control is before buying it.
I agree, I had a 5 HP 220 25 gallon crafstman with just a pressure switch, that was a 1982 model, and a 25 gallon Black max by sanborn 5 HP 220 set up the same and they never gave me any trouble. I also had a here but only for a short time an 80 gallon vertical sanborn 5 HP 220 that has a electromechanical contactor but wasn't hooked up. It ran fine for me, fine for my buddy for years and fine for the original purchaser. I no longer have those here or I'd look to see about the switches. Now all three of those motors had their own thermal protection , reset button on the motor itself. My 3 phase stuff all has a electromechanical contactors or mag starters with thermal overload protection. My 220 single phase hvac heating and cooling unit has a mag starter or an electromechanical contactor and that was 85.00 for a new one. IF IF IF the ratings are the equal I see no reason why that contactor wouldn't operate any piece of 220 equipment if you wanted it to. Something like this : http://www.pressureparts.com/260296 What exactly are you buying for 500.00 ? Did you check to see : Is just the contactor bad? Is it the pull in coil? Is it the thermal breakers? Capacitor if it has one ? Is it getting its trigger signal?
I have an old IR T30 compressor also. Took it out of an old auto dealership recently and working on converting it to 1 phase 5hpmotor 220v. You can use a rewired 3 phase contactor with correct heaters. I have a good link from GJ on wiring the pressure switch, contactor and motor.will post a link here when I find it. The 1 phase motor will draw almost 30amps under starting load.A good contactor will provide overload protection for an expensive motor.
HERE you go, this is from Eaton Compressors and is what they use on their 5HP models. And it's only twenty dollars. Call "em, every compressor part I've ever needed they've been more than helpful with, and I've bought one of those, and two pumps in the last three years for both my compressors....
Granger sells a condor brand pressure switch thats rated for 30 amps more than enought for 5 hp motor for about $55.00.
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