Air compressor electric motor

[johndeere123]

I am buying a compressor to replace the old one in my small shop at home. I found an 80 gallon 5hp one and am thinking of buying it. It has a 600V 5hp motor on it. I have a 220V 5hp motor at home that I want to use on the compressor. Is their any power difference between 5hp 3 phase and 5 hp single phase?

 

[OldandWorn]

Are the RPM's the same on both motors? You may need to go larger on the control/start contactor wiring or do some mods to the start contactor as the current on a single phase is much higher and not divided between the 3 phases. As a general rule your single phase motor should work.

 

[willie59]

Agreed, if motor rpm and hp rating the same, it should work. But as stated, the single phase motor will pull more amps to do the same (hp) work than a three phase motor of same hp rating.

 

[FSERVICE]

one thing not mentioned is make sure rotation is the same

 

[SeaMac]

If you wish to use a 3ph motor you have to have a 3ph electrical service or you can purchase and have an Electrician install a phase converter -NOT a DIY'er weekend project. In all my years as an Electrician I never ran across a 600v motor that was not 3ph. As OldandWorn stated the motors should spin at the same rpm for your application and that information is on the motors name/spec plate. As willie59 indicated, if the hp and rpm are the same it should work however there are numerous types of motors -I won't bore you with the details- but the frame type is very important as it will determine if one motor's frame will fit in the place of a motor it replaces. As FSERVICE indicates, motor rotation is also critically important, you do NOT want it spinning backwards as that can be destructive to that which it is connected. Only 3ph needs to have rotation checked and typically most motors have an arrow identifying rotation on the fan cover. There's one other thing that is important and that's shaft size and keyway, as with all the different types they all have different shafts. And few others, duty rating and cycles again all this info is on the name/spec plate. Here in the States we generate 60 cycle alternating current there are 50 cycle motors out there and they will have issues with reliability when connected to 60 cycle ac. In as much as possible the spec plates should match *** for tat.

Also, the NEC and National Electrical Manufacturers Assoc (NEMA) provide a maximum rating to 600v for low/medium voltage systems, is it possible the 600v you mention is that or does the plate actually say 600v ac?

Surely you have a electric motor shop nearby, it may be worth while having them take a gander at your motor. Just out of curiosity how did you come across a 600v motor, they are generally only used in extreme industrial applications. Mostly you'll find 120/240 1ph, 120/208 3ph and 277/480 3ph the latter being most prevalent in commercial and common industrial applications.

Good luck...

 

[VoodooMojo]

..... 80 gallon 5hp... 600V 5hp motor on it. I have a 220V 5hp motor at home that I want to use on the compressor. Is their any power difference between 5hp 3 phase and 5 hp single phase?

No, they will both consume 3730 watts of power under full load.
The difference will be the amount of total current needed to operate the 5hp at full load.
With 600 volts the full load current would be a mere 06.2 amps.
With 220 volts the full load current would be a not mere 16.9 amps.

What information do you have about the compressor head itself?
CFM, SCFM, Single Stage, Two Stage, Pulley Size...

And I guess as important as the rest of it all, what is the intended use? Filling up an occasional tire or sandblasting a bridge?

 

[SeaMac]

Voodoo,

Your calculations are spot on for 1ph but, does he have a 600v, 3ph electrical service where this compressor will be used? By his OP it would appear no, I think we're all awaiting further information.

No, they will both consume 3730 watts of power under full load.
The difference will be the amount of total current needed to operate the 5hp at full load.
With 600 volts the full load current would be a mere 06.2 amps.
With 220 volts the full load current would be a not mere 16.9 amps.

What information do you have about the compressor head itself?
CFM, SCFM, Single Stage, Two Stage, Pulley Size...

And I guess as important as the rest of it all, what is the intended use? Filling up an occasional tire or sandblasting a bridge?

 

[VoodooMojo]

The current at 5hp for the 600 volt 3ph would be 1.77 amps.

 

[OldandWorn]

I know this isn't one of your questions but I should also mention a possible problem with the motor control on this compressor. If your motor/compressor is really rated for 600 volts you will most likely have to change the coil or contactor so it will operate on 220/240 volts.

 

[norite]

It is perfectly feasible to replace a 5hp 3ph 600v compressor motor with a 5hp 1ph 240v motor. Motor control is still going to be typically 120v same as already used at 600v. The 600v/120v control transformer will not be necessary as the 120v control voltage can be taken from the 240v supply between one of the hot wires and the neutral, so the coil is fine the way it is. The 3 phase contactor in the starter with a 120v coil will work fine also, only two of the three contacts need be used. Current will be approx. 21A IIRC and the overload heaters in the starter will need to be replaced with larger ones suitable for your actual full load current. If the overload relay is settable then set it for the appropriate overload current.

FYI 600v is the industrial 3ph voltage typically used in Canada (550/575/600v) wheras in the US they use 480v (440/460/480v) in industrial 3ph systems.

You should consider the age and condition of the compressor tank, I believe they need to be re-certified by a hydrostatic test every 10 years or replaced with a new one.

It is definitely doable, be sure to get an electrical permit and consider hiring an electrician, the cost is minimal compared to firemen and doctors.

 

[johndeere123]

I have a 5hp 220v electric motor sitting in my shop now. the compressor has a 600v 5hp motor on it. I cant get 600v at my shop. I want to buy the compressor and put my 5hp single phase motor the compressor itself is a Binks 33-1036. I cant find much information on it, but it is in great shape.

 

[SeaMac]

I'm not entirely sure how you intend to derive 240v from a hot and neutral unless you were to remove the neutral from it's bus and land it on one of the spaces on the 3-pole breaker. The NEC does not allow such a practice as it entails the use of phasing tape on the once neutral now hot conductor and if smaller than #6 AWG the conductor color shall be continuous. Here, that would be a big NO NO!

As for Canadian voltages, that makes perfect sense, what about AC cycles are you 60 cycles or 50? I have worked on and wired a batch plant with all European equipment with their 3-ph max being 380v. Learn sumpin new everyday, thanks...

The 600v/120v control transformer will not be necessary as the 120v control voltage can be taken from the 240v supply between one of the hot wires and the neutral, so the coil is fine the way it is.

FYI 600v is the industrial 3ph voltage typically used in Canada (550/575/600v) wheras in the US they use 480v (440/460/480v) in industrial 3ph systems.

 

[OldandWorn]

I have a 5hp 220v electric motor sitting in my shop now. the compressor has a 600v 5hp motor on it. I cant get 600v at my shop. I want to buy the compressor and put my 5hp single phase motor the compressor itself is a Binks 33-1036. I cant find much information on it, but it is in great shape.

If it's in good shape at a fair price I say go for it, at least I would. More information would be helpful though....like RPM's of each motor which could be a fixable but annoying change if not close to each other.

 

[OldandWorn]

I'm not entirely sure how you intend to derive 240v from a hot and neutral unless you were to remove the neutral from it's bus and land it on one of the spaces on the 3-pole breaker. The NEC does not allow such a practice as it entails the use of phasing tape on the once neutral now hot conductor and if smaller than #6 AWG the conductor color shall be continuous. Here, that would be a big NO NO!

As for Canadian voltages, that makes perfect sense, what about AC cycles are you 60 cycles or 50? I have worked on and wired a batch plant with all European equipment with their 3-ph max being 380v. Learn sumpin new everyday, thanks...

He is from Canada and it sounds like he is familiar with this compressor and their voltages. The OP would simply have to run a 4-wire (hot-hot-neutral-ground) to the compressor, at least that's the way I'm reading it.

 

[SeaMac]

OldandWorn,

Oh no doubt, norite's very well informed I'm just curious how it would be done though I know nothing of Canadian Codes and Practices. Generally speaking in the US when we do motors/controls all the motors are supported with load voltage by the Motor Control Center (MCC) which is usually 480 3ph and all the starters have their own control voltage panels usually 120v 1ph fed and derived from a separate system. The NEC with few Fine Print Note exceptions does not allow for circuits/conductors from separately derived sources to share the same raceway, conduit etc.

He is from Canada and it sounds like he is familiar with this compressor and their voltages. The OP would simply have to run a 4-wire (hot-hot-neutral-ground) to the compressor, at least that's the way I'm reading it.

 

[OldandWorn]

OldandWorn,

Oh no doubt, norite's very well informed I'm just curious how it would be done though I know nothing of Canadian Codes and Practices. Generally speaking in the US when we do motors/controls all the motors are supported with load voltage by the Motor Control Center (MCC) which is usually 480 3ph and all the starters have their own control voltage panels usually 120v 1ph fed and derived from a separate system. The NEC with few Fine Print Note exceptions does not allow for circuits/conductors from separately derived sources to share the same raceway, conduit etc.

I'm not sure that I follow you. Maybe read his post again? He is saying that the control (contactor) coil is 120 volts thus the need for a neutral. It would be no different than a hot tub, Dryer, Range, or similar that needs a 120 volt circuit along with 240 volts.

 

[VoodooMojo]

another component to consider is the start capacitor.
Verify the start capacitor is the correct uf and voltage rating for your application.


For your 220 volt motor under full current load about 340uf is needed.
The voltage rating must be at least equal or larger than line voltage.
Measure the voltage at the unloaded source to verify this voltage.

If the uf value of the start capacitor is too high, the motor will accelerate the compressor too quickly
causing belt and bearing damage.

If the uf of the start capacitor is too low, the motor will accelerate too slowly
or not at all, causing motor damage or a burning/exploding capacitor.

If your motor has a run capacitor also, be sure it is at least 1.5 times the line voltage.
In your case, 370volts will work nicely.

 

[SeaMac]

Oldandworn,

Yep, I re-read his reply and you too are correct, Hot Tubs, Dryers and Ranges all require a neutral as well 240v but it is uncommon to provide a neutral for motor loads, copper being the cost it is these days common practice is two or three hot's -phase dependent- plus a ground. There are occsaions where a 120v circuit is made 240v by removing the neutral from it's bus and landing it on a 2-pole breaker. In such cases common practice was to phase tape the neutral either, black, red or blue so to identify it as HOT. Trouble being you have only identified the change at the far-end and the panel but not any junction boxes in between. If say in the future someone were to tap into that circuit without previous knowlege of the change and considered the white or grey wire as a bonafied neutral it could be catastrophic if what they thought was only 120v turned out to be 240v. Hence the decision I believe in the 1996 NEC cycle to no longer allow the use of phase tape on conductors smaller than #6 wire. All conductors smaller than #6 must be identified continuously along their entire length. The obvious exception are conductors larger than #6, although colored insulation is available in virtually all gauges most supply houses only stock standard old black and happily sell you colored phasing tape. They will gladly special order anything wire you'd like at a nominal fee of course.

I'm not sure that I follow you. Maybe read his post again? He is saying that the control (contactor) coil is 120 volts thus the need for a neutral. It would be no different than a hot tub, Dryer, Range, or similar that needs a 120 volt circuit along with 240 volts.

 

[SeaMac]

VooDoo,

This poor guy, all he wanted was some simple info and we've loaded him up with all kinds of Sparky Speak. If I were in his shoes I would take it that yes, it can be done but take his motor and parts to a local electrical pump and motor shop or compressor shop and allow them to figure it all out. As was previously mentioned, if electrical work at the place where the compressor is to be used is required, absolutely hire a LICENSED Electrician and pull a permit. If Canada is anything like the lower 48, you do work without a permit where one was required and a fire is the result, your insurance company will simply hand you the bill for repairs and the Fire Department will add their cost to the invoice.

 

[VoodooMojo]

VooDoo,......This poor guy, all he wanted was some simple info and we've loaded him up with all kinds of Sparky Speak. ....

I get a bit carried away at times but sometimes it is important to point out that
all things may not be as easy as they seem. For safety reasons.
I didn't want to hear later that his shop burned down or someone was zapped.