ingersol rand ss5l5 wiring plug amperage/nema stuff

shannonw · Nov 13, 2011

hi!

Ok so i've had this CL find in the garage sitting about 6 months. Had a bad motor, picked up a killer deal on a new motor finally, baldor 5hp (21 or so amps running same specs like the original emerson)...like 125 bucks!

I've seen people seem to do ok with 30amp breakers on similiar 22amp motors, but IR says like 50. I have a short 5ft max run to the compressor and the dp 50amp breakers seem cheap enough i figured I'd just go with the manufacturer rating or 40-50.

Anyways planning on 40-50amp 220v breaker, 8 gauge wire (have some left over from other projects), i'd imagine 10g would work but i have this already. Was planning on 40a dryer receptical and cord as opposed to wiring directly (breaker in sight and pressure switch has a switch)...though would like it to twist lock or something..but i'm not familiar with other receptacles really.

Reading some nema googling, i see a lot of 50 amp plugs but they'll rate them in 1-2hp which leads to my questions:

1) what's this HP rating on nema plugs? Does it apply in this situation?
2) I see lots of people using range/dryer plugs but I assume these are similar in terms of hp ratings?

That hp stuff is just throwing my basic diy electrical knowledge for a loop there....making me wonder if i should just hard wire it.

THANKS!

evintho · Nov 13, 2011

Hard wire it right off the dryer recept. Very easy to do. That way you won't have to worry about the HP rating on the plugs. I have an I/R SS5N5 (same as yours except for an 80gal tank). There was a 220v line already installed in my house so I just hard wired that into the compressor switch. Installed a 50a breaker in my panel. Probably a 40' wire run from panel to compressor. Use it daily. Haven't had any problems in 5 years.

Al Bundy · Nov 13, 2011

I agree, hard wire it. I ran 6 gauge wire from the panel to a shut off box. Then hard wired the compressor to the shut off box. Double check on the breaker. I thought they called for 60 amp. But then again I'm getting old and may not remember correctly.

Charles (in GA) · Nov 13, 2011

The hp rating is due to the huge inrush of current when the motor starts. This is peculiar to motors like this and something like a dryer would not have any significant inrush of current beyond whatever its normal load is.

Charles

shannonw · Nov 13, 2011

Thanks for the replies and charles for the hp rating explanation (makes sense). Sounds like hardwire is the way to go, simpler anyways too. with a bit more googling i did run across higher hp rated nema plugs 7-50 and such and not cheap =P i'll hardwire.

Odd though when googling tons of people seem to go this dryer or some other plug route but surely are exceeding the hp ratings on the plugs....not small compressors either 5hp 22amp ones surely pulling the same startup.

i'll just go straight from the breaker to the pressure switch or put a cut off box for convenience in between there. I think ir does say 60 i'll step up to 50 or 60 there.

Shadowdog500 · Nov 13, 2011

I Literally just sat down from wiring my IR SS5L5.

The motor has a FLA of 21.5 and a SFA of 24.4.

I confirmed with my neighbor (licensed Electrician) that 30 amp fuse with 10 gauge wire is all you need.

I just finished my 30 minute break in run on the new circuit and everything stayed cool and fine.

Where did you see 50 AMP?? IR didn't give any recommendation other than saying to read the motor data plate.

Im getting old. I pulled MC wire about 16 foot up over my garage door and probably went up and down my ladder about 50 times.

My neighbor last said to get twist lock plugs because there have been fires from dryer plugs. The guy at Colonial electric agreed.

Chris

Al Bundy · Nov 13, 2011

Read your manual. 30 amp is sufficient for operating the compressor, but there is a large spike at start up. I would go with the manufacturer's recommendations, not your licensed electrician buddy. And yes you can get away with number 10 wire, but for the sake of a couple dollars is it really worth it?

Shadowdog500 · Nov 13, 2011

Al Bundy said:
Read your manual. 30 amp is sufficient for operating the compressor, but there is a large spike at start up. I would go with the manufacturer's recommendations, not your licensed electrician buddy. And yes you can get away with number 10 wire, but for the sake of a couple dollars is it really worth it?

Read it cover to cover. My manual said to see the motor plate for current info then check codes for breaker size. No amperage was given.

Where did you see 50 AMP?

Chris

shannonw · Nov 13, 2011

Chris i can't tell for sure, it's not in the manual that I can see..

Mine's 2nd hand but being it had a bad motor and they aren't cheap! i googled on the model and motor looking for a replacement and saw a lot of posts on several boards (ham,jalopy journal,etc) emerson motor failures on this model and people calling IR....only to be told direct wire to 50a due to startup amperage. So i dunno... maybe that's just a manufacture being safe spec wise.

the failures are coincidence i'm sure, i'm positive if i searched for husky,kobalt,etc i'd see similiar posts on motor failures...not like the motor is IR..pretty much one of the 3 brands used on other similar price range compressors...weg, leeson, emerson.

But i saw lots of discussion re 30 vs 50amp, i checked out a few other compressor manufactures which basically use a similar size, running amperage, hp motor or baldor and they all seem to recommend 40-60. price difference is negligiable on the breaker so i was just going to go 40-50 to be safe...60 seems a bit overkill =/ but i dunno...seems high to me too.

If mine was under warranty i'd do what IR says, might take a phone call though as the requirement doesn't seem to be in the manual.

sberry · Nov 13, 2011

If you have the 8 wire why not use it. I have ran comps in this class for years from 10/30 but you could go to 50A if needed, would be a legal circuit for that machine. I still have some from back in the day with range cords,, yes I confess but they are mounted in a grounded box, if I am doing some cobble deal cause its the hardware I have at hand, using metal box on a cable I ground the box. It still ain't legal cause its not listed for it. The yoke of an old 3 wire appliance is not grounding type where the yoke of the device is bonded to the ground pin,,,, Clear as mud? Feel free to elaborate.

Shadowdog500 · Nov 13, 2011

Breakers are designed to handle this momentary start up draw. Here is a table that shows a breaker trip current vs time. Most can handle a hell of a lot of current for a short period of time and like 2X the rating for close to 10 sec. The important thing is that the breaker blow before something is damaged. Note the wire damage curve to the right of the trip profile.

As long as the start up current and duration are left of the trip curve you are fine.

Too much breaker isn't good either because even if you run 8 wire things can burn up in compressor before the breaker blows.

I agree to run what you have. I had 10 wire available for free.

Chris

shannonw · Nov 13, 2011

yeah i was wondering the same thing today...with so many people seeming to run 21amp motors on 30 you'd think it would be safer than over sizing the breaker so much,but then again i'm not an electrician =)

sberry · Nov 13, 2011

These motors have their own thermal protection, the breaker is there primarily for short circuit, 10 wire is good for more than 125% continious motor load, the breaker cannot be larger than the fault current the wire can support, basically 12, one of the code guru types here can say for sure but actually this might be legal with 12 to 50A in pipe? 10 cable?

shannonw · Nov 13, 2011

searched on another site i read, seems touched on pretty well here in laymens terms though the guy isn't an electrician it does point out roughly why 30 would be ok

http://www.sawmillcreek.org/showthr...-breakers-for-3HP-and-5HP-shop-motor-circuits

so manufacturers are likely rating just for the max (which would make sense covering all the bases).

sberry · Nov 13, 2011

I have never had one trip a 30 where there wasn't something wrong with it.I got one, secondary comp, I think the draw is 24 and one at 18, the one at 18 actually had it on a 20 for long time never tripped, when I moved it I ran 2 circuits in new location, both 10/30. About 6 inches of wire from brkr to recept and 3 ft of cord. V drop or loss was a moot issue.

shannonw · Nov 14, 2011

yeah i'm so close to the box i'm sure 10/30 would be fine in this case too.

sberry · Nov 14, 2011

This is in general and a lot of guys have the expertise over me but its worth gaining some understanding.
The breaker here doesn't protect the machine or even the wire, the connected load does in the fact that its limited, much the same as a light bulb. Put a 100 watt lamp on a 12 wire and a 50A breaker, essentially a safe situation, the lamp wont overload the wire and the wire is heavy enough to trip the breaker in the event of a fault.

sberry · Nov 14, 2011

A motor circuit may follow the same principle to some extent with some additional factors, needs wire heavy enough it doesn't overheat, plus a pinch and heavy enough so that during the start it delivers current considering the V drop thats gonna happen. Breaker big enough or have enough delay that it doesn't trip during this start.
Could be several other factors, type of wire, even wiring method, cord, cable, etc, breaker or fuse design, most all of it really over my head and rather irrelevant to me for the most part during normal installation of a piece of equipment.
Generally we need to look at a unit, provide a wire one size larger than the cord and or read nameplate,etc, size breaker for the demands not to exceedXXXX. Lots of stuff out there all particular, I usually read the manual if possible or am already familiar with it. Things can seem strange, a small wire feeder, say 180, allows for a wire smaller than the cord, they list the max breaker at 35,,,, true if you are using 14 (they list ground wire to be 12) but once the wire is 12 or better you can run this machine to 50A breaker, they are listing the max brkr with the min wire, you could hook 2 of these machines, with their own 12 wire back to 50A circuit and be legal.

sberry · Nov 14, 2011

Developing some understanding would help in circuit design, take a woodworking shop for example, 10 machines sitting around, if every one needed a separate circuit we would eat up 20 breaker spaces, 2 or 3 at a time could be used off of single circuit, breaker there for short circuit and each load calculated. Ideally designed so someone cannot come along and connect additional load at random via extra recepts like one would find on a general 20A 120 circuit.

Shadowdog500 · Nov 14, 2011

But this will be a dedicated circuit so load is known.

I just reviewed the manual and while it don't give breaker size it does say that slow-blow or time delay breakers are preferred due to the startup current.

Chris

shannonw · Nov 14, 2011

yeah i reread and saw they basically say follow nec guidelines.

I was just looking at a typical 5hp general purpose motor spec on baldors site,

http://attachments.temcoindustrialpower.com/product_info/Baldor-PL1327M.pdf

So assuming the normal nec code stuff, I'm assuming this means that to trip a 30amp breaker the compressor motor would have to be @~150%+ load presumably due to something wrong, if normal running a compressor pump of this size is 100% load or not i don't know. starting current 128 amps...i had no idea it was that high. Does make me wonder about the plug and outlet though and the hp rating of the plugs

Shadowdog500 · Nov 15, 2011

I ran mine with the bead blast cabinet for the first time tonight with no problem. It is great not having to take a break for the air to recover!

Run the #8 with the 40A that you planned. Eaton recommends 40 AMP breaker for their 5HP 220V single phase compressor.

http://www.eatoncompressor.com/AMPDRAWBREAKERSIZE.html

Chris

shannonw · Nov 15, 2011

Yeah i'm going to do that since i already have #8.

Just curious ,how loud did you think the compressor was? I just have a small jobsite now and bum an older 26 gallon from the neighbor. both are noisy as heck. The jobsite is oiled but loud as heck i wear ear plugs. The 26 gallon is oiless so you know how loud those are.

Shadowdog500 · Nov 15, 2011

About 90dB standing right next to it. My old Craftman 2HP is actually a little louder.

Here is a video I made for another thread.

Chris

Mmfh · Nov 15, 2011

Shadowdog500 said:
I ran mine with the bead blast cabinet for the first time tonight with no problem. It is great not having to take a break for the air to recover!

Run the #8 with the 40A that you planned. Eaton recommends 40 AMP breaker for their 5HP 220V single phase compressor.

http://www.eatoncompressor.com/AMPDRAWBREAKERSIZE.html

Chris

Hey Chris,
I'm wondering about your blast cabinet, mine might be bigger than yours but I have a lot of wait to catch up time with my 60gal, 6.5hp vertical.

What type blast cabinet are you using?

Mm

Shadowdog500 · Nov 15, 2011

Mmfh said:
Hey Chris,
I'm wondering about your blast cabinet, mine might be bigger than yours but I have a lot of wait to catch up time with my 60gal, 6.5hp vertical.

What type blast cabinet are you using?

Mm

I have a really old Dee Blast. I believe it is a model 34 but I will confirm that tonight. I'll also confirm the specs tonight but i believe it only calls for 14CFM. My new compressor provides 18 CFM @ 90. Blasting with my 2HP 30 gallon was a joke, the new compressor makes it fun. See photo below. It is a table top model but the person I got it from made the roller table for it.

Chris

PT Doc · Nov 15, 2011

Could someone explain the relevance of ratings on plugs? If a plug is rated for 240v and 50a and you are powering a compressor that is spec'd by the manufacturer to be on a 50a breaker, how does the hp rating of the plug come into effect? This hp rating I don't think leviton puts on the plug even. Thanks

Gary S · Nov 15, 2011

Shadowdog500 said:
I Literally just sat down from wiring my IR SS5L5.

The motor has a FLA of 21.5 and a SFA of 24.4.

I confirmed with my neighbor (licensed Electrician) that 30 amp fuse with 10 gauge wire is all you need.

My 5hp compressor is wired similarly. It has a run rating of 22amps. It is on a 30amp breaker with #8 wire. #10 would have been sufficient, but I like larger than normal wire for faster motor startup.
The breaker curve takes care of the high inrush current during startup, so a 50 amp should not be needed. The 30 amp gives you quicker protection in case of some kind of failure.

Shadowdog500 · Nov 15, 2011

Just checked and it is a model 34 and uses 12CFM.

I looked everywhere a d can't find any info on it but Dee-Blast also made this into a parts washing cabinet for Snap On.
See this thread: http://www.garagejournal.com/forum/showthread.php?t=117855

shannonw · Nov 15, 2011

PT Doc, yeah i'm still wondering the same thing myself about the HP ratings of the plugs (even though i've decided to hardwire). I've done a few googles but nothing I would understand, seems plug & socket HP rating is pretty relevant from the links i've seen but i have no idea really...the ones i've seen with that are all the nema connectors

Mmfh · Nov 16, 2011

Shadowdog500 said:
Just checked and it is a model 34 and uses 12CFM.

I looked everywhere a d can't find any info on it but Dee-Blast also made this into a parts washing cabinet for Snap On.
See this thread: http://www.garagejournal.com/forum/showthread.php?t=117855

That's interesting that Snap on made a wash cabinet with that as the base unit. I've never seen one like it. I looked again and my blast cabinet wants 35 cfm, that's why my compressor doesn't like it.

byoungblood · Nov 16, 2011

shannonw said:
PT Doc, yeah i'm still wondering the same thing myself about the HP ratings of the plugs (even though i've decided to hardwire). I've done a few googles but nothing I would understand, seems plug & socket HP rating is pretty relevant from the links i've seen but i have no idea really...the ones i've seen with that are all the nema connectors

I just wired my compressor with a 6-50 plug and was done with it. I wired the outlet with the expectation of buying a 220v welder sometime in the future, so I just went ahead and used the higher current plug on my compressor. The particular plug I bought could actually be used with a 6-30 recepticle by swapping out one of the blades too.

shannonw · Nov 16, 2011

Right but that's amps, my question was about the hp ratings on these (kinda moot in my case since i'm hardwiring now). I could be 100% wrong, but a 6/50 looks to have a 3 hp rating

http://www.frentzandsons.com/Hardware References/plugandreceptacleconfiguratio.htm

http://www.grainger.com/Grainger/HUBBELL-WIRING-DEVICEKELLEMS-Straight-Blade-6C119

So i'd assume for a 5hp ~21amp compressor you'd need a 5hp rated one but i dunno...

PT Doc · Nov 16, 2011

So what happens when you run 6g wire on a 50 breaker terminating at a 6 50 (240v, 50a) plug and connect a 240v compressor that is rated at 23fla that is 5hp. All the numbers work out but how does the 5hp play into this equation?

shannonw · Dec 26, 2011

Anyone see a problem with using a slimline 220v 40amp breaker? Never used them but it's all I have the room for without switching some other breaker to a slimline. If they are essentially the same this is a bit easier..

shannonw · Dec 27, 2011

Just an update on this confusing topic in case someone runs into it =)

if you decide to run 8/40, check the pressure switch connectors, but more importantly the availability of terminals for 8 gauge. My pressure switch uses male terminals, OF course ...hd doesn't carry females in 6-8 gauge (should have expected this...), only 10 and up....screw terminals would be so much better. Not sure about lowes...i would probably need to make time (tough to find) to go to some electrical supply or order online..have to keep reminding myself to avoid the convenience of the big box stores..inevitably there will be something they don't have!!

That said, i'm just going to run 10/30 and if it trips worry about it then, unless i have to make an unexpected trip in town. i'm only 5 feet from the panel....saves cutting the left over 8 gauge i have for other projects.

sberry · Dec 27, 2011

You are going to be fine with the 10/30, I have never seen one trip where there wasnt something wrong with the starter.

Shadowdog500 · Dec 27, 2011

Mine is working fine with the 10/30!

Chris

shannonw · Dec 29, 2011

Thanks for all the info on this thread, got it fired up this morning!

http://www.garagejournal.com/forum/showthread.php?p=1978237#post1978237

ingersol rand ss5l5 wiring plug amperage/nema stuff

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Banned

Well-known member

Well-known member

Banned

Well-known member

Banned

Well-known member

Banned

Banned

Banned

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

MEMBER EMERITUS

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

MEMBER EMERITUS

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Banned

Well-known member

Well-known member