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Topic Review (Newest First)
10-18-2007 09:36 PM
blsnelling I ordered the Siemens starter and on/off switch today. My retired elcetritian friend will wire it up for me. OldRed, you can rest easy now
10-18-2007 09:09 PM
66GMC Don't get me wrong here ...
I am not going against the advice that oldred has given you.

You asked about a grainger catalog, and I am supplying you with a link to their On-line Catalog

SAFETY first!
Money is replaceable ...
but body parts and lives ... not so much!
10-18-2007 06:24 AM
oldred Use that Siemens with the pressure switch you have (provided it is not damaged by the time you get the starter) and a disconnect for shutting off the power, you don't need that on-off switch. Only running the compressor when you are around is kind of like playing Russian roulette if you are thinking you can just run over and kill the power when the pop-off valve releases, that thing may not work if it has already popped a few times and is contaminated with crud from the tank it very well could stick and you would not know it until it is too late! Since the switch that came with it was stuck how many times has that valve had to release? You have only an idea of how much current that Motor is actually drawing and the switch you have may or may not work, a thermal overload on the motor will not help out here. Don't kid yourself you are playing with fire here, you have a large compressor with a heavy draw, with parts that have been changed and an inadequate switch. This is not a toaster in the kitchen this thing can hurt you and I am not joking.
10-17-2007 08:30 PM
blsnelling I'm reallin liking the looks of this Siemens when used with this SWITCH.
10-17-2007 08:06 PM
blsnelling How's this Square D compare to the Seimens? LINK Is the 30A too low?

This Seimens is rated 40A. LINK
10-17-2007 07:23 PM
blsnelling I'm working on the mag starter end and I'm only running the compressor when I'm present. Otherwise it's not turned on. Here's the motor I have. LINK . Is it thermally protected or not? I don't see where it says anything about it.

Does anyone have a Grainer catalog where they could point me to the proper starter? Or is the one I found on eBay a better price than I'll get at Grainger.
10-17-2007 06:19 PM
Originally Posted by blsnelling
Are either of these applicable?

That Seimens in the second link would do nicely and honestly you do need it. Even if it runs fine now it may not for long with just that pressure switch.
10-17-2007 06:15 PM
oldred You already have a problem, that switch is rated at 21 AMPs and the motor is 23. The switch should NEVER have a rating less than the motor rating, not even 2 AMPs less and things of this nature is EXACTLY why you need to get an electrician to check this out. That switch MAY work but then it may not and since the motor was changed you would need to do a current check with a meter to know for sure how much current that thing is pulling, guessing or assuming is recipe for disaster. If it sticks, and it very well could, then the ONLY thing standing between you and disaster is that pop-off valve - are you willing to bet your life it will work when you need it? Do you realize how much damage an over charged tank of that size is capable of? Compressor accidents do happen and when they do it can be very serious, this is nothing to take a chance on and that switch you have is chancy at best. Are you sure you have this thing grounded properly? If you don't it may run fine but knock the crap out of you when you least expect it!
10-17-2007 05:32 PM
blsnelling Are either of these applicable?
10-17-2007 05:14 PM
blsnelling I stopped by Tractor Supply on the way home from work to take a look at the new IRs. All the 5HP models use a pressure switch wired directly into the motor. The 7.5HP with the T-30 pump uses a mag starter. I took a look at their replacement 2-stage pressure switch and it was a Square D 9013FHG52, marketed by CH, and it stated it was good up through 5HP and 21A. I've installed one, put in new oil and a new air filter and am back up and running. I'm leaving the power switch off when I'm not in the garage using it.

Now I hear what you say OldRed and would like the added safety of a mag starter. Is there a particular one that's a good deal that I could add? I definately like the idea of taking the current load off the pressure switch contacts. I have a friend that's a retired electrician, so installation's not a problem. I'd just like to know if there's a particular model you guys recommend.
10-17-2007 08:39 AM
oldred [QUOTE=blsnelling]
LINK . The specs seem to indicate that this is only for a 2HP motor. Is that the source of the problem? [QUOTE]
Absolutely no doubt!

The 9013GHG2J62 looks to be a better choice but is still only rated for 3HP,LINK . What switch do I need?
NEITHER ONE! Neither of those those switches will work and don't let anyone tell you they will be ok! The 3 HP rated switch will work for a while but it too will weld shut and it probably will not last long so if it seemed to work at first it could lure you into a dangerous situation. What you need is a starter or relay switch so that the pressure switch will not have to carry the load to the motor. You really need to get an electrician to look at this thing and help you out because if you do this wrong, and it is EASY to make a mistake, you could damage the compressor and very possibly yourself. If you decide to do this , and I highly recommend you don't, then go down to the electrical supply and tell them what you have and they will be able to set you up with the right parts. I have said this before and I stand by it-trying to wire a 5 HP motor, especially on something as dangerous as a compressor, is NO PLACE TO LEARN WIRING! Not without a competent coach looking over your shoulder anyway. I am in no way trying to say I don't think you are smart enough to do this I am sure you are BUT like most people you probably just never had the need to do it before and there simply is no room for error. I have had to re-do a bunch of compressor hook-ups that the owner was sure he could do himself and it was probably the most common service call I got to a non-commercial installation. The wrong switch, just like the problem you have, occurred quite often but the most dangerous error was improper grounding-this can kill you! Usually when I tried to explain a grounding problem they would say "but it runs just fine" just because it runs does NOT mean it is wired right! If you do this yourself then you should at least get an electrician to check it out before you turn the power on but whatever you decide DON'T attempt to use either of those pressure switches by itself because it WILL stick and could very well cause damage and/or get you hurt..

Don't worry about that oil I am sure it did not hurt a thing.
10-17-2007 06:20 AM
blsnelling Is there another oil besides the T30 Select that I could use in this compressor?
10-16-2007 10:36 PM
blsnelling I ended up buying a used compressor today. Found it on Craigslist. I got a Ingersoll Rand 2475N5 which is 5HP, 80 gal, 175 PSI, T-30 pump, 16.8 CPM @ 175. It originally had a 3-phase motor. That has been replaced with a brand new Baldor, 23A, sealed. He ran it for me and all looked good. It appears to have been used very little. I gave him $800 for it.

I brought it home, wired it up, and turned it on. It wouldn't shut off. Turns out the contacts on one side of the pressure switch are welded shut. The switch that is on it is a Square D FHG49S2, LINK . The specs seem to indicate that this is only for a 2HP motor. Is that the source of the problem? The 9013GHG2J62 looks to be a better choice but is still only rated for 3HP,LINK . What switch do I need?

The other concern is the oil level. This compressor had not been used in years and appears to have been used very little. I ran the compressor for a total of <10 minutes. When I checked the oil, it was way below the threads of the fill hole, which is how you check it. I drained the unit and only got 20 oz, although there's still a little that won't drain. It has a capacity of 41 oz. The compressor runs great and is quiet. Is that low enough that 10 minutes of operation would have hurt it?

How's this for performance? 0-100 took 3 minutes. 0-175 took 5 minutes and forty seconds. 137-175 took 50 seconds.

I'd really appreciate any help or advise you can give me on the pressure switch. I'd like to get this thing operational ASAP.
10-15-2007 06:58 PM
SteveU Is the pressure lubed model for the average guy doing weekend warrior worth the extra money? What would the model you linked to go for in a 5 hp configuration? Looks like a great compressor
10-15-2007 06:49 PM
oldred You are right in that nothing you listed will come close to the Eaton in performance and as far as that Ingersoll that has come up before already here and in other threads. Ingersoll has been pretty good with their ratings before so maybe it is the retailer but that 18.1 CFM@90 PSI for that particular model is fantasy IMO and I have checked a hell of a lot of compressors over the years, 14 CFM or MAYBE even 15 on a good day. If you want a better compressor than the Eaton then check out a Quincy. One of the two stage Ingersoll outfits is also really good and will probably last nearly a lifetime if you take proper care of it but something like that U.S. General may not last nearly as long although it does not look bad for the price, key words here being "for the price".

IMO Quincy is the best you can buy but they are a bit spendy, thirty years from now while you are still using the thing it may seem quite cheap however. I am not exaggerating about that thirty years and I can think of two Quincys that are at least that old that have been used regularly without a whimper, out of the pumps anyway. One is a gas powered outfit that has worn out a couple of engines and a tank but that pump is still going strong and has not had any major repair done to it during this entire time. You just will not find a better compressor than Quincy.
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