Big boy Air compressor build HELP?

[jcobra99]

So i decided to build the last home compressor i will ever need. However i need some help rigging the pump i got to the tank. I found a nice
Champion R-30 Compressor pump a while back. Then i found a Like new 120 gallon tank that was bought plumbed and never used just sat outside and build some surface rust. I painted the pump black already and will be doing the same thing with the tank. I plan on buying a 10HP baldor motor for this setup.

I need to figure out what is the best way to run the line out of the pump that goes into the tank. I belive the one way valve that prevents air from coming back out is a "check valve" ? could be wrong. I have the one that was on the tank the pump originally was on. I just need help on how i should go about rigging this up. I attached some pictures. And the intercooler lines ect for the pump i still have they are just not pictures.

 

[pvfjr]

Yeah, you'll want that check valve. You should also install a safety pop-off valve on the tank. Getting a pressure switch that has an unloader feature would also be good. I you get tired of fussing with it, I'll trade my functioning compressor straight across for your pile of parts.

 

[jcobra99]

The plumbing coming out of the tank is huge looks like 2IN so i just need to get some fitting to rig the check valve into that plumbing? Does it matter if the check valce is much smaller diameter than the plumbing going into the tank? Yeah i plan on installing a couple safety pop off valves around the tank. What exactly is an unloader feature? also is 10HP baldor to much for residential? i keep hearing different answers. The pump is 15HP and 50cfm capable to a figured 10hp would be perfect. haha id take you up on that offer but this build has been a mission of mine years in the making lol

 

[redmondjp]

You should really check with your local utility to see if you can even start a 10HP single-phase motor (good luck finding one of those) on your existing electrical service.

Have you priced out a 10HP motor and starter yet? Be sitting down when you do. I must have my Champion compressor pump data file stored on my computer at work, but you need to look up the specifications for that pump and see what the minimum HP motor you can use with it. I'd see if you can go down to either a 7.5HP or a 5HP motor.

 

[PKashub]

Most pumps are rated at their maximum rpm, so a 15hp pump means that it needs 15hp motor to turn it at its max rpm, which can be somewhere between 1000-1400rpm (check manuf data). They also specify minimum Rpm the pump can turn, and that requires a lot less HP. I think you can turn a 15hp pump at min rpm (~600) with a 7.5 motor. Anything bigger in residential wiring would probably dim lights when motor starts. To run 7.5 Hp motor they recommend running a 6 gauge wire and 50 amp circuit breaker. You will size pulley to spin pump at desired rpm, there are online formulas how to size pulley.


iPad Tapatalk

 

[jcobra99]

Yeah this pump can use a 7.5hp - 15hp motor. Ive found both on ebay for fairly decent prices. The 10hp of course being quite a bit more pricey. Even with 6G wire and the correct size breaker would i not be able to run it? I have the pully that came with the pump that was used with a 7.5hp motor and the pully for a 7.5hp motor

 

[redmondjp]

Yeah this pump can use a 7.5hp - 15hp motor. Ive found both on ebay for fairly decent prices. The 10hp of course being quite a bit more pricey. Even with 6G wire and the correct size breaker would i not be able to run it? I have the pully that came with the pump that was used with a 7.5hp motor and the pully for a 7.5hp motor

In that case, definitely go with the 7.5HP motor. You'll need a NEMA size 2 starter for that size motor. Those aren't cheap. You can also use an IEC (European electrical specification) starter which is less expensive and will have an adjustable overload (so you don't have to select and install the proper sized heater strips like you do for a NEMA starter). But, the IEC starter is not as beefy and robust as a NEMA starter.

When you are looking at the starter specifications, make sure that you are looking at the single-phase specifications for HP, at 230/240V. A 7.5HP motor is going to draw 40-45 Full Load Amps (FLA) and your starter has to be able to handle that, as well as the inrush starting current. You don't want to cheap out on the starter.

Plenty of other threads on this site cover all of this ground if you do some searching.

 

[jcobra99]

Would this starter be adequate


http://www.ebay.com/itm/280639333310?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

 

[Mr onetwo]

That starter will work ,but is not a NEMA rated motor starter.I would look for a used Cutler-Hammer or Square D NEMA starter on Ebay. Cost is always a consideration and it may take a while to find a cheap used one. NEMA stuff is overbuilt and I would trust it more.

 

[jcobra99]

Ok i found some brand new square D nema starters on ebay for $200 ill grab one of those. What is a nice top of the line pressure switch for the tank? And what exactly is an "unloader feature?

 

[Mr onetwo]

Make sure you get the right heaters for that starter. I have used this on 2 compressors that I refurbished and sold....they are very high quality. http://www.ebay.com/itm/HEAVY-DUTY-...754859?hash=item3efb75832b:g:ge0AAOSwRLZUD1TZ The unloader line connects to the pressure switch and relieves pressure upon hitting high limit.That way the compressor doesn't start against high pressure upon call for start.

 

[motofool33]

i couldn't trust my large compressor with that starter(chinese shihih), i went with a New WEG style with start stop functions on my 7.5hp conversion of my 10hp 3 phase compressor.

http://www.temcoindustrialpower.com/products/Motor_Starters/MS0033.html

and these guys have cheap pulleys:
http://www.electricmotorwarehouse.com/

 

[nadogail]

Enjoy you compressor in good health.

 

[Gary Anderson]

Shalom to you my friend...

Your Pal, Gary

 

[mg283680]

Regarding the motor HP vs RPM and the pump, an X HP motor at 1750RPM is roughly 2x the price of a 3450RPM motor at the same HP. HP is a calculated value with no units based on torque*RPM.
That means the slow motor is ~twice the size, cost and goodness of the fast motor. Sadly consumers will buy fast motor, burn it up and whine.
Pump RPM is the product of the ratio of pulley diameters and motor RPM. How's that for BS?

Regarding safety, a guy that rebuilds compressors told me that compressors are dangerous, as in they're bombs. Think about the dangerous stuff in the garage. I have a compressor at 175PSI, and a midsize O/A setup. In a big fire both are a hazard.

Don't scrimp on compressor bits...

 

[LS6 Tommy]

Might as well sell the parts now. A 10 hp single phase compressor duty motor will cost close to the same as a more reasonably sized new compressor...

Tommy

 

[jcobra99]

I bought a 7.5HP baldor. I could have got a 10hp baldor for right at 900-950. The pump alone i got for my compressor goes for 2500-4k depending on where you buy it.

 

[jcobra99]

i couldn't trust my large compressor with that starter(chinese shihih), i went with a New WEG style with start stop functions on my 7.5hp conversion of my 10hp 3 phase compressor.

http://www.temcoindustrialpower.com/products/Motor_Starters/MS0033.html

and these guys have cheap pulleys:
http://www.electricmotorwarehouse.com/

What heaters would i need for that starter?

 

[matt_i]

I would not use heaters on a single phase motor, and especially if you are going to be present when the machine runs. Overload heaters are there to detect phase loss, which will burn the windings on a 3 phase motor, because it cannot start on a single phase and will hum with a locked rotor at max amperage.... if nobody is present to quickly shut it off.

On a single phase motor, you drop a phase, the motor can't even attempt to start.

 

[matt_i]

Regarding the motor HP vs RPM and the pump, an X HP motor at 1750RPM is roughly 2x the price of a 3450RPM motor at the same HP. HP is a calculated value with no units based on torque*RPM.
That means the slow motor is ~twice the size, cost and goodness of the fast motor. Sadly consumers will buy fast motor, burn it up and whine.
Pump RPM is the product of the ratio of pulley diameters and motor RPM. How's that for BS?

A 3450rpm motor is a 2 pole motor. A 1725/1750rpm motor is a 4 pole motor. There are 6s and 8s, I forget those rpms, like 1200 and 900.

The more poles, the greater the weight, and most importantly, the greater the torque.

Without an unloading apparatus, the motor can potentially have to start against full load, the pressure switch closes the contacts probably around 20psi drop from the shutoff function in normal function.

Is that compressor a 4 piston single stage? I don't see any tubing connecting a small piston to a large piston. Possibly that's done with internal porting, but the tube gives a place to lose heat along the way...often they are finned to assist heat transfer using the "fan-flywheel-sheave"

 

[A_Pmech]

I would not use heaters on a single phase motor, and especially if you are going to be present when the machine runs. Overload heaters are there to detect phase loss, which will burn the windings on a 3 phase motor, because it cannot start on a single phase and will hum with a locked rotor at max amperage.... if nobody is present to quickly shut it off.

On a single phase motor, you drop a phase, the motor can't even attempt to start.

Phase loss protection is a small aspect of a the heater section of a motor starter.

The purpose of the heaters are to mimic the stator heating rate of a prototypical motor. Thus, the device time to trip will vary in proportion to the overload current. This allows the motor to be temporarily overloaded, yet protects the stator insulation by limiting the stator temperature.

 

[jcobra99]

What heaters should i use?

 

[matt_i]

You don't need heaters with that starter. It has a bimetallic overload circuit breaker function if you read the specifications..........

"•Bimetallic overload relays - class 10"

"•Ambient temperature compensated for -4°F to +140°F, eliminating the need for heaters"

Personally, I would pick up an Allen Bradley or Square D Nema Size 1 starter, used, eliminate the overload section, and let someone in the next generation worry about it.

 

[redmondjp]

You don't need heaters with that starter. It has a bimetallic overload circuit breaker function if you read the specifications..........

"•Bimetallic overload relays - class 10"

"•Ambient temperature compensated for -4°F to +140°F, eliminating the need for heaters"

Personally, I would pick up an Allen Bradley or Square D Nema Size 1 starter, used, eliminate the overload section, and let someone in the next generation worry about it.

Well for that matter, just get a 2-pole contactor (online) that is rated for that horsepower and voltage and put it into an electrical box. That's all the motor starter is if you are not going to use the overload function.

 

[AndrewDouglasBird]

And what exactly is an "unloader feature?

An unloader bleeds the pressure off the pump when the motor shuts off. This makes it so there isn't pressure in the pump when the motor kicks back on, making for a lighter load start.

 

[rockymnt]

Welll !! did you get this going?? I have a personal interest in this as I have the same compressor but on a horizontal tank I picked up for $300.00. It has the 10 hp 3 phase and I want to change it.

Thanks

 

[motofool33]

Welll !! did you get this going?? I have a personal interest in this as I have the same compressor but on a horizontal tank I picked up for $300.00. It has the 10 hp 3 phase and I want to change it.

Thanks

what part do you need help with rockymnt?

 

[rockymnt]

Mostly wanting to know what kind of starter I will need/ or may not need, to use on the 10hp single phase motor. The 3 phase 10 hp motor came with a magnetic starter, but I don't think it will work.

 

[jtmcclain]

Do an eBay search for Nema size 2 starter. That's what you need for a 10 horse single phase motor.