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?
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.
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.
one thing not mentioned is make sure rotation is the same
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...
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?
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.
The current at 5hp for the 600 volt 3ph would be 1.77 amps.
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.
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.
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.
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...
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.
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, 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.
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.
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.
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.
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.
VooDoo, I hear 'ya and know exactly what you mean. It is always better to err on the side of caution when it comes to electricity and take it from a long time Sparky, most folks don't fully understand and that weekend seminar at the local Big Box store or the book they'll sell 'ya "all" about electricity could be a ticket to the E.R. or worse.
I have no intentions on wiring it in myself, its worth the couple of bucks to get it done right the first time. I appreciate all the feed back from everyone.
First of all with few exceptions most mcc's and motor starters DO NOT have separate sources of control power, it is derived from the feed to each starter by using a control transformer to step the supply voltage down to the control voltage. O/P wants to replace 600v 3ph 5hp motor with a 220v 1ph 5hp motor. Assuming same rpm this is easily and commonly done. The O/P is presumably installing the compressor at his residence or garage and has only 240v 1 ph power available, no 600v, 3ph power or MCC's and such. Residential power is single phase with two 120v to ground hot wires with a neutral. Voltage from either hot wire to neutral is 120v and voltage from hot wire to hot wire is 240v same as you have in the US. Frequency is also 60hz just like in the US. Difference is in the industrial 3ph systems, we have 600v phase to phase while in the US it is 480v phase to phase. Since the O/P is from Nova Scotia (Canada) he will follow the Canadian elect. code (CEC) rather than your NEC, which is with a few exceptions very similar. He just needs to install a 2 pole breaker in his panel feeding a cable or conduit with 240v which is 2 120v hot conductors a neutral and a ground. Assuming he is using the motor starter he can disconnect the 600v control transformer and tap one of the incoming hot wires and the neutral at the starter to get 120v for control power. I won't go into further detail which is why I strongly recommend getting a permit and an electrician as there are many considerations such as conductor sizing, breaker sizing, O/L sizing, contactor sizing, grounding etc to consider. Hopefully this answers your questions.
norite, With all due respect, I have been a State Unlimited Electrical Contractor (EC) in Florida for 17 years, been an Electrician for 36 years. Far from "few" circumstances where the motor control is not centralized Programmable Logic Loop Controled (PLLC) in which the control voltage is separately derived. True, the older style starter cabinets had their own step down (buck) transformers to provide control voltage and Hand, Off, Auto (HOA) functionality. These days the with the prevalence of Variable Frequency Drives (VFD), energy management (EMS) and automation systems the "control" for such systems is indeed derived separately. I couldn't agree more, hire a licensed and qualified Electrical Contractor and obtain a permit and inspections by the local AHJ.
SeaMac I too am qualified and experienced. Please don't presume that what you do is the right way and what we do here is wrong, we both have to conform to similar but different codes and standards of engineering practice to suit our local jurisdictions. I think we have gotten way off topic and it is time to move on. cheers:drinkup
norite, I had no doubt that you were qualified and experienced, no presumption on my behalf either, I have been "field educated" many times on non-US systems. It fascinates me how other Countries go about electrical work. And yes, we all bow down to our respective AHJ's. Yes again, we seemed to have veered off topic. Let's hope the OP gets his compressor issue straightened out without much money or hassle. Cheers to you as well...
:drinkup I'll drink to that!
That sure is a lot of dancing around and horn blowing for saying......oops, I was wrong. Well, that is another feather in your cap. You have been "field educated" on a US system by a Canadian.:canada And that my friend, is how even incompetent AHJ's obtain bloated egos and feelings of power. :beerchug
OldandWorn, We laid this to rest or so I thought, since we strayed too far from topic. No right, no wrong, simply different systems, practices and standards. What we do here differs slightly from what our neighbors up north do. I most certainly need no educating on the US system other than mandated CEU's which by the way are a joke and only pertain to new OSHA regs, slight changes in the latest NEC cycle and business related mumbo jumbo. We cannot generally win a battle with City Hall, if the Authority Having Jurisdiction (AHJ) is an incompetent dolt, you mostly have to accommodate their stupidity if you want their signature on a permit AND wish the customer to pay you. So, let's all drink to differences, stupid Inspectors and getting back on topic, YAY! :drinkup