Compressor wiring questions

[screamincamaro]

I picked up a Quincy 2V41C60VC single phase 5hp/230v/21amp. I've searched, have been doing some reading, and now have additional questions on wiring it up.

At minimum it sounds like I need a 40 amp breaker for main box, 8 gauge wire @20-30 feet, conduit, and wire it directly to the compressor.

http://www.garagejournal.com/forum/showthread.php?t=123926&highlight=2V41C60VC+wiring

1. Do I need a disconnect box between main breaker box and compressor?

http://www.garagejournal.com/forum/showthread.php?t=156881&highlight=2V41C60VC

2. It sounds like a magnetic switch is optional for the model I have.
a. Would a magnetic switch bypass start/stop controls that come on the compressor or is it in addition to it?
b. Is a magnetic switch meant to act as a disconnect or start/stop switch for regular daily use?

 

[Labradorian]

I picked up a Quincy 2V41C60VC single phase 5hp/230v/21amp. I've searched, have been doing some reading, and now have additional questions on wiring it up.

At minimum it sounds like I need a 40 amp breaker for main box, 8 gauge wire @20-30 feet, conduit, and wire it directly to the compressor.

http://www.garagejournal.com/forum/showthread.php?t=123926&highlight=2V41C60VC+wiring

1. Do I need a disconnect box between main breaker box and compressor?

http://www.garagejournal.com/forum/showthread.php?t=156881&highlight=2V41C60VC

Based on canadian electrical code......NEC should be same or very close.
You can use #10 with a 30A breaker, voltage drop is fine at 30feet. But you are still within code with #8 with a 40A breaker.

As per section 28-604 of the canadian electrical code, the location of a disconnecting means of a motor can be at the panel from where the motor is fed from as long as the main panel(disconnecting means) is within sight and within 9 meters of the compressor.

beyond that you can put a disconnect at the compressor for convenience or an added level of safety.

if you add a disconnection means at the compressor it has be able to add a lock to it to quallify as a disconnection means. it also can be a non fused disconnect, a fuse or breaker is not required assuming that it it fed from a breaker at the main panel.

2. It sounds like a magnetic switch is optional for the model I have.
a. Would a magnetic switch bypass start/stop controls that come on the compressor or is it in addition to it?
b. Is a magnetic switch meant to act as a disconnect or start/stop switch for regular daily use?

Based on canadian electrical code......NEC should be same or very close.
You can use #10 with a 30A breaker, voltage drop is fine at 30feet. But you are still within code with #8 with a 40A breaker.

As per section 28-604 of the canadian electrical code, the location of a disconnecting means of a motor can be at the panel from where the motor is fed from as long as the main panel(disconnecting means) is within sight and within 9 meters of the compressor.

beyond that you can put a disconnect at the compressor for convenience or an added level of safety.

if you add a disconnection means at the compressor it has be able to add a lock to it to quallify as a disconnection means. it also can be a non fused disconnect, a fuse or breaker is not required assuming that it it fed from a breaker at the main panel.

Cheers

 

[Moose364]

30 amp Breaker and the 8ga wire should be fine

and Yes I would put in a disconnect of some type, breakers were never made to be used as switches

 

[2x_Tom]

I installed my compressor and just switched it in the panel. It got old after a while and I added a 30amp double pole switch. Cost me less then 20 bucks for the switch, box and cover plate. Well worth having the switch right next to the compressor.

 

[Charles (in GA)]

Based on canadian electrical code......NEC should be same or very close.
You can use #10 with a 30A breaker, voltage drop is fine at 30feet. But you are still within code with #8 with a 40A breaker.

As per section 28-604 of the canadian electrical code, the location of a disconnecting means of a motor can be at the panel from where the motor is fed from as long as the main panel(disconnecting means) is within sight and within 9 meters of the compressor.

US NEC is 50 ft and line of sight (NEC defines the term "line of sight" to include the 50 ft restriction, you have to look in the definitions to find it.

beyond that you can put a disconnect at the compressor for convenience or an added level of safety.

if you add a disconnection means at the compressor it has be able to add a lock to it to quallify as a disconnection means. it also can be a non fused disconnect, a fuse or breaker is not required assuming that it it fed from a breaker at the main panel.

NEC does not require a means to lock it, just the ability to disconnect the power.

Cheers

5 hp is a huge load for a pressure switch to control. Generally its at 5 hp that you start using magnetic starters for switching the motor power on and off, leaving the pressure switch the simple task of controlling the relay in the magnetic starter.

That being said, it appears that the 2V41C60VC model may not have a "full" 5 hp motor on it. for one, it spins faster 1310 rpm vs 942 rpm of the next 5 hp model, and it produces less air, 15.2 AFCM vs 17.2 ACFM (both at 175 psi) of the next 5 hp model up. Its also 205 lbs lighter, some of which is the smaller tank, but I'll bet some is the motor being lighter, and some is the slightly different pump.

They don't offer a MAX package for this model, so apparently Quincy does not feel the need for a magnetic starter.

Charles

 

[screamincamaro]

I attached the motor specs if that helps

 

[LX-Markham]

I added a 30amp double pole switch. Cost me less then 20 bucks for the switch, box and cover plate. Well worth having the switch right next to the compressor.

This is what I did.

http://www.amazon.com/Leviton-MS302-DS-Disconnect-Industrial-Non-Grounding/dp/B002MPQ51O/ref=sr_1_1?ie=UTF8&qid=1376597331&sr=8-1&keywords=leviton+ms302-ds

located it next to the door so I just flip the switch when i walk into the garage.

 

[r_egan]

I have the same compressor. Added a 30 amp breaker and wired it to an outlet. Added a cord and plug to the compressor instead of hard wiring to a disconnect box.

 

[pattenp]

I'd hardwire it with #8 with a 40A breaker to be NEC compliant.

 

[C96]

The SPL motors are…should I say… ****?

Didn’t realize Baldor made that BS too, also getting disappointed with Quincy putting out cheapo compressors with garbage components.

By the way, that is not a 5hp motor. It’s like 3.7hp of deceit.

If Quincy keeps this up, they will soon lose their reputation and fall to the lowest level as did IR years ago with their cheapo ****.

 

[pattenp]

The SPL motors are…should I say… ****?

Didn’t realize Baldor made that BS too, also getting disappointed with Quincy putting out cheapo compressors with garbage components.

By the way, that is not a 5hp motor. It’s like 3.7hp of deceit.

If Quincy keeps this up, they will soon lose their reputation and fall to the lowest level as did IR years ago with their cheapo ****.

How do you figure that?

 

[C96]

How do you figure that?

Using a horsepower to amperage chart

If you notice on the motor nameplate where the HP rating should be there is the letters SPL which translates to: “Some People Lie”…Lol, actually refers to “Special”

These type motors are usually requested by inferior compressor manufactures trying to produce a product as cheap as possible. Having a SPL (“Special”) rated motor allows the compressor manufacture to then hype up the actual rating of their unit fooling consumers into thinking their getting a much better bang for their buck. The 5hp claim their making is most likely the peek hp rating the motor can produce just prior to giving up the ghost.

 

[screamincamaro]

That's it I'm putting it out on the curb. Kidding...

So I think l'm going to use 40amp breaker, 8 gauge wire, add a disconnect, and call it a day. I'm also going to try one of those moisture minders to keep the moisture out of the tank.


Maybe I'll add a magnetc switch down the road. Thanks

 

[C96]

That's it I'm putting it out on the curb. Kidding...

So I think l'm going to use 40amp breaker, 8 gauge wire, add a disconnect, and call it a day.

That should be plenty adequate for the compressor.

screamincamaro, didn’t mean to bash your compressor like that. Just pissed me off when I saw the picture of the motors name plate. What irks me is when manufactures try to pull the wool over consumers’ eyes with erroneous horsepower ratings by using these SPL motors. Quincy has a very good reputation for quality compressors, but more and more I am seeing them do this. Another thing many companies do is omit the mag starter and spin an underrated pump at a higher RPM trying to squeeze out every last cfm. This makes it appear the consumer is getting more when in fact they are getting much less. This added RPM puts more wear n tear and stress on the unit along with making it noisy and susceptible to premature failure.

 

[pattenp]

Using a horsepower to amperage chart

The motor data label says 21 amps, so what chart are you using coming up with 3.7HP? If the 21A is correct then I get 5.4HP, 230V X 21A = 4830W, 4830W / .84EFF = 4057W, 4057W / 746W = 5.4HP

If you're going by the NEC chart, that is for sizing conductors and is over inflated for safety. This chart is closer to actual... http://hvacwebtech.com/motoramps.htm
or this.... http://www.onlineconversion.com/motor_horsepower.htm

 

[C96]

The motor data label says 21 amps, so what chart are you using coming up with 3.7HP? If the 21A is correct then I get 5.4HP, 230V X 21A = 4830W, 4830W / .84EFF = 4057W, 4057W / 746W = 5.4HP

If you're going by the NEC chart, that is for sizing conductors and is over inflated for safety. This chart is closer to actual... http://hvacwebtech.com/motoramps.htm
or this.... http://www.onlineconversion.com/motor_horsepower.htm

so what chart are you using
A chart based on article 430.

If you're going by the NEC chart, that is for sizing conductors
Yes, and for sizing other components that make up the electrical motor circuit. Also, it’s used for converting FLA to HP ratings when no HP rating is listed on the motor name plate 430-6 (A)(1).

over inflated for safety
Lol… Hell yes it is, that’s exactly what it’s designed for and what we here in the USA must adhere to.

This chart is closer to actual
Actual what, laboratory test ratings?

The .84 efficiency you’re using is based on the motor in a testing lab under the utmost perfect conditions. The NEC takes into account many different motor manufacture ratings thus creating a comprehensive chart to go by.

That Baldor “SPL” motor was specifically design engineered as cheap as possible to meet minimum requirements for Quincy.

Seriously, if that motor actually put out 5 true horsepower why then wouldn’t they just stamp the nameplate accordingly instead of having a “SPL” mystery motor? This makes no sense.

Seems any motor manufacture would be proud to list their HP rating rather than cover it up behind a fictitious “SPL” rating unless they had something to hide.

 

[pattenp]

Seriously, if that motor actually put out 5 true horsepower why then wouldn’t they just stamp the nameplate accordingly instead of having a “SPL” mystery motor? This makes no sense.

Seems any motor manufacture would be proud to list their HP rating rather than cover it up behind a fictitious “SPL” rating unless they had something to hide.

The air compressor manufacturer does not make the electric motor, but buys it from a motor manufacturer. The motor manufacturer doesn't mark the HP rating on the motor and instead marks it SPL to show that it's made for special use. This protects the motor manufacturer if the motor finds its way to a use different than what it was designed. I don't believe the motor manufacturer is trying to hide anything. If anyone is over inflating the HP it's the compressor manufacturer when they put that big sticker on the side of the compressor that states the HP.

I agree with you on the use of the NEC table for meeting conductor sizing requirements of the NEC for motors, but the conversion charts I pointed to give a closer number to the actual HP of a motor based on FLA. We are talking about the calculation HP by two different means. Obviously the NEC chart is to be used when wiring a circuit for a motor to comply with code.

 

[Gerald O]

The motor data label says 21 amps, so what chart are you using coming up with 3.7HP? If the 21A is correct then I get 5.4HP, 230V X 21A = 4830W, 4830W / .84EFF = 4057W, 4057W / 746W = 5.4HP

^^
This. Except I'd lower the efficiency estimate a bit for the less than optimal load match due to the impulses in the load. Even at 78% you still get over 5 usable hp.

 

[pattenp]

^^
This. Except I'd lower the efficiency estimate a bit for the less than optimal load match due to the impulses in the load. Even at 78% you still get over 5 usable hp.

I used the Eff% that's on the motor data label.

 

[Gerald O]

I used the Eff% that's on the motor data label.

Didn't see that--not used to them actually putting it on the motor. That's actually not bad for an induction motor used in a consumer grade application!

 

[C96]

The air compressor manufacturer does not make the electric motor, but buys it from a motor manufacturer. The motor manufacturer doesn't mark the HP rating on the motor and instead marks it SPL to show that it's made for special use. This protects the motor manufacturer if the motor finds its way to a use different than what it was designed. I don't believe the motor manufacturer is trying to hide anything. If anyone is over inflating the HP it's the compressor manufacturer when they put that big sticker on the side of the compressor that states the HP.

I agree with you on the use of the NEC table for meeting conductor sizing requirements of the NEC for motors, but the conversion charts I pointed to give a closer number to the actual HP of a motor based on FLA. We are talking about the calculation HP by two different means. Obviously the NEC chart is to be used when wiring a circuit for a motor to comply with code.

The air compressor manufacturer does not make the electric motor, but buys it from a motor manufacturer.
Agreed, but in this case Quincy actually has Baldor build this motor “Special” just for them with the secret “SPL” ratings. The numbers listed on the motor nameplate reflect this as a Quincy OEM part number and only available through Quincy themselves. This motor is not available through Baldor.

The motor manufacturer doesn't mark the HP rating on the motor and instead marks it SPL to show that it's made for special use.
Exactly, like stated above, this particular motor was built exclusively as per Quincy specs, whatever those may be is anyone’s guess.

If anyone is over inflating the HP it's the compressor manufacturer when they put that big sticker on the side of the compressor that states the HP.
Totally agree with this. It’s sad this activity goes on, don’t understand why a reputable company can’t just be frank and upfront with what their selling.

Always seems to be some gimmick involved…

 

[catfish500 mark]

Hello fellas, Im new to the site and have been debating on whether or not to chime in on this.I have been going through this exact situation myself.I burnt up my old compressor sandblasting with it.I was researching compressors and found the Quincy 2V41C60VC or QT54 (same thing) and was going to purchase it also.I called a local compressor dealer in my home town and first thing he said was, dont buy that one if you need it for sandblasting.He proceeded to tell me about that model compressor.He said it was a knock off of a true Quincy and it would not hold up for what I needed.I fugured he was just wanting to sell me a more expensive model.Although he has been in business here for over 25 yrs I still felt the Quincy was what I wanted.My sandblaster is just a small model from TSC.I called another but less reputable dealer and he said the same thing.The Quincy 2V41C60VC/QT54 is Quincy's economy compressor in line with Ingersoll Rand's 2 stage compressor and those along those lines.After a ton of more research and a budget that would only allow me to do so much, I called the first dealer back and took his advise on purchasing a Curtis 2 stage 7.5hp 80 gal QT series compressor.There was a substantial added expense of additional wiring needs Im having to do but it should serve my needs just fine.I went with #4-4-4-6and a 60amp breaker with additional ground rod running 84 ft in length from the disconnect at the meter base to the new subpanel.I still think that I could have gotten by with the Quincy but I wanted a compressor that would be more than adaqate.I also learned that pump rpm is of the utmost importance and a true 5hp motor is too.Quincy still makes a great compressor and if one is not sandblasting alot with the qt54 it will do just fine.Here is a picture of the Curtis compressor going in my shop.

 

[wyliesdiesels]

Now that were done debating HP semantics, we need to find out from the OP if the pressure switch is actually rated for the HP of the motor. If its not, it will fail sooner than later!

 

[C96]

catfish500 mark welcome to the Garage!

That is one bad-*** machine you have there!

Glad to see you upgraded and boy did you ever…

 

[warren57]

Not sure why you want a 40 amp circuit to feed a 20+ amp load, a 10 gauge 30 amp circuit should be adequate.
Voltage drop doesn't factor in until you exceed 50', so with nearly no voltage drop, amperage isn't going to increase, so I would install a 30 amp circuit.
Never hurts to be larger, maybe one day you will increase compressor size and need it, but doesn't appear you do right now.

 

[screamincamaro]

I agree it's going to be located within sight of the breaker box and they actually recommend 50 amp breaker and a minimum of 10 gauge in the instructions. I figured 50 was overkill and decided on 40amp/8 gauge because I only wanted to do the wiring once and also in case there is higher amp draw upon startup. I'm not an electrician but figured I couldn't go wrong upsizing slightly.

 

[600SL]

The SPL motors are…should I say… ****?

Didn’t realize Baldor made that BS too, also getting disappointed with Quincy putting out cheapo compressors with garbage components.

By the way, that is not a 5hp motor. It’s like 3.7hp of deceit.

If Quincy keeps this up, they will soon lose their reputation and fall to the lowest level as did IR years ago with their cheapo ****.

I didn't relies Baldor or Quincy would stoop to this either. But I will say that at least the motor has a 21 Amp rating consistent with a good 5HP motor. The bottom line when buying a compressor is CFM at a realistic pressure. My 3.7 HP Lowes compressor is rated at 17 Amps, which is consistent with 3.7 HP. I have been finding the compressor manufactures to be a little more honest these days compared to days of the 6 HP ratings I used to see on Sears compressors with a 120V plug. Shop Vacs have yet to get the message. But I concur that if it has a SPL rating it is an inferior product.

 

[my58dodge]

"Inferior product"? I've owned my QT54 for about a year and it supplies my blast cabinet just fine. Guys on here will say you need a $3000.00 compressor minimum to operate your small blast cabinet! LOL. The QT54 has a 30,000 hour pump life and a 100% duty cycle; that's years and years of use in the hobby shop environment. I paid $1250.00 for mine by shopping around, and have found it to be a good running, reliable compressor.

 

[pattenp]

There is absolutely no correlation to a motor having SPL listed instead of the number of HP to being an inferior product. I've seen cheap made motors with the HP listed.

 

[wyliesdiesels]

Not sure why you want a 40 amp circuit to feed a 20+ amp load, a 10 gauge 30 amp circuit should be adequate.
Voltage drop doesn't factor in until you exceed 50', so with nearly no voltage drop, amperage isn't going to increase, so I would install a 30 amp circuit.
Never hurts to be larger, maybe one day you will increase compressor size and need it, but doesn't appear you do right now.

Code requires 35a rated wire for a 5HP motor which means #8 NMb/Romex or #10 THHN....and a max breaker of 70a...