34cfm Duplex Compressor Project, any pros here that can give advice?

[jonjon1]

I have been wanting to do this for a long time, I have saved some parts for this project for a while, and I have been cleaning up so its other get rid of it all or finish it once and for all...

HERE IS WHAT I HAVE..
2- Brand Spanking New Ingersoll Rand 2475 T30 pumps, Wrapped in plastic, never even had the pulleys mounted or oil put in them!!!!

2-Brand new Eaton 5hp starters, I bought these a while back for a good price at a local parking lot sale, for this project specifically, I wanted to find a duplex controller for this system, but never stumbled across one, I do have one that says "230v 3hp single phase" that came off of a duplex 7.5hp 3 phase system, but I was told it wouldnt work, so that is in the "sell" pile, if anyone is interested, its in nice shape, would be good for a dual 3hp setup, a pair of 60ga 3hp units for $300 each wired to this unit would give you 25 cfm for cheap...

2- used sheaves and bushings, for a 184t frame motor, will give me around 920 rpm at 1725.

2- air dryers, 1 25cfm and 1 15cfm, both never used, scratches here and there, but never used...

AND the REASON I started this project, a 120 gallon Heavy Duty horizontal Ingersoll Rand receiver, it was only like 5 years old when I got it, but now its about 13 years old, but in nice shape... This tank weighs about 500#'s, its the one with the frame built around it, has 3/8" plate welded to it, lol... SUPER HEAVY DUTY... I used it for a long time for storage, but now there is no air running to it, I am going to move it to the home garage this week sometime....

SO, I need a few little things, like air cleaners for the intakes, pressure switches, check valves, psi relief valves, and I will fab all the copper tubing up myself...

SO I need some advice...

1st, which pressure switches? And how would you wire this? I was thinking get adjustable switches and set one to come on at 120 and off at 150, then the other pump on at 100 and off at 150...

Is there a box I can buy that will alternate the pumps using my eaton mag starters? Or a better way to do this I dont know about... Something like the dayton 051 like I would use on condensate drains in a commercial building?


2nd, Which motors, I was looking at the weg 1.25 sevrice 184t 5hp, it looks strong at 109lbs, but the baldor l1430t is the normal go to for me...

3rd, will this work properly with 2 air dryers? I was going to tee them in together, and when I know I am using more than 25 cfm I turn on the large one, when I am going to be using more cfm I kick the other one on too, I figure a ball valve on each to isolate them will work well enough....

4th, Is there a good way to find a diagram on how to run the pipes for this? I can figure out how to run it all but not positive where all the reliefs should be?

I think that is all my questions for now, I will post some pictures when I bring the tank home, I am on the fence of sand blasting it and coating it or just cleaning it up, I guess I will power wash it and then make a decision...

thanks in advance, I know there are a couple pro members here that work on pumps all day, and I know a lot of you boys have built more compressors than me, so if you can offer some help, I would appreciate it...

this is what I am shooting for, but with out the big control box, I got a price on that and you WOULD NOT want to know what it was, lol..
http://www.amazon.com/dp/B0040C01Y4/?tag=atomicindus08-20

 

[md21722]

Normally duplex compressors would have a tank capable of accepting two compressor discharge lines. Typically these are copper though braided stainless is becoming more common. Each would get a check valve to prevent tank pressure from backing up into the pump. The air dryers would come later in your distribution system. Ideally at least 25 feet from the tank. The tank would have "one" outlet to the distribution system and you would put the regulators and air dyers close to the point of use. Adjustable pressure switches are normal, often set at +5 and -5 five and wired into an "alternator" which will cycle the compressors for light use and run both simultaneously when needed. In some cases, manufacturers will combine the mag starters & alternators into a "control unit" but there is no real need to do so. Hubbell/Furnas is one manufacturer of air compressor alternator. Install a gauge and pressure relief on the tank. You only need one. Weg or Baldor seem fine. One of the biggest killers to motors is a fail safe going out and it continues to run & burn itself out until the breaker trips (assuming it does) or under sized wiring. If you are running in 2 x 5HP (23A 230V) motors that's 46A 230V. Should be 6 gauge wire or bigger if the run is considerable distance from the panel.

 

[jonjon1]

Thankd MD, I have to put the dryers right ontop of the unit sadly, I was going to run 2 separate 30 amp lines, its only about 12 feet of cable...


SO I could use a 24v alternator with 2 separate mag starters?

 

[Finky198]

We currently use an IR2475 7.5hp 80gal... so I'm am officially subscribed I would love to add a second one into the system. Best of luck looking forward to this I can't wait for some pictures

We have 8' of 4 gauge wire on a 60amp breaker. When it trips it has shut down our entire 100 amp sub panel that also runs our lights (we're gonna be putting in 200 amp services soon) I would recommend over estimating your electrical needs

 

[jonjon1]

WOW, your 7.5hp bops a 100a breaker? Does the 60a blow or just the main? If its the main then that just means, your lights, etc with the compressor running is more than 100, but if its bopping the 60a and the only thing that is coming off of it is the compressor, that is a lot of juice...

I plan on running these at a lower pressure too, so starting wont be AS bad, plus I am only running 5hp, that 7.5hp weg motor turns like 3550 and pulls some amps, it is HUGE too, lol.. I like that setup a lot...

I like the idea of running the alternator, BUT I am not sure I will be able to run 2 separate starters?

 

[md21722]

Yes, you run two mag starters with an alternator. The mag starters are simply taking line voltage and either turning the load on or off with a pressure switch or other device as an trigger. You could feed them separately from a pressure switch, or wire in an alternator. If you use the alternator, it would take in the pressure switch output and signal the mag starters. The high current lines are between the panel and the mag starters. The alternator and pressure switches would just be signaling.

 

[jonjon1]

I can get this alt for $65
I am used to hvac wiring, and when using something like this we have to use a 24vac t-former, and use switching relays that allow you to use your own input on the switch side, because some switching relays have their own 24v transformers, so when you wire two of them in a tt circuit it makes it a bit more tricky...


http://www.eaton.com/ecm/idcplg?Idc...eased&Rendition=Primary&&dDocName=IL04906001E

My question is for the control above, where would the power to run it come from?

Unless its like a sump pump and they run on line voltage? If this is the case I would need a 220v unit?

 

[md21722]

Looks like you've linked a file on your desktop.

 

[jonjon1]

sorry I fixed it go back to that post and click the link, its a pdf...
heres is a picture of it the pdf shows the instructions..


http://www.eaton.com/Eaton/Products...trol/RelaysTimers/AlternatingRelays/index.htm


I noticed eaton compressors uses 2 magnetic starters and an alternator...
https://www.eatoncompressor.com/piston-compressors/premium-dual-units-7-5-20hp

 

[sberry]

I might be tempted to hook this up like two separate units, If this is for a small garage 1 will supply all the needed air, flip the other one on for hi demand work. Alternating is ok when these were running on top of the duty cycle and wear and maintenance may have been a concern but a guy cant wear one out at home.
I use 2 comps, breaker isn't even on to the backup. If I am going t blast turn it on.

 

[jonjon1]

I might be tempted to hook this up like two separate units, If this is for a small garage 1 will supply all the needed air, flip the other one on for hi demand work. Alternating is ok when these were running on top of the duty cycle and wear and maintenance may have been a concern but a guy cant wear one out at home.
I use 2 comps, breaker isn't even on to the backup. If I am going t blast turn it on.

That is plan B, and was my initial thought, I was going to wire a switch panel where I can turn on or off each compressor and dryer. I am also going to install hour meters on each pump.

So when I am just running air tools, spraying, etc. I can run the air dryer that matches my load (either the 25 or the 15) dryer and a single pump.

When I am running multiple DA's, blasting, etc I can turn on both pumps and both dryers..

Then I can manually keep the alternate using each compressor so they wear evenly, run one as a lead for one oil change interval then swap to the other as lead...


THE only thing about that I wasnt crazy about was I would rather not have both pumps starting at once....


I already designed a solenoid system to run the dual driers, so I can flip a single low voltage switch and it will turn on the drier and direct air through it, and when the switch is off it will turn off the drier and stop air from flowing through it...

 

[sberry]

How much work are you planning to do? A large tank really stretches out the duty cycle. I got 200 gallons and use 3 hp and can finish what I am doing before air is an issue.
I can be thrifty and do auto body from 3 at 80 gallons but its really a job for 5 hp. The added tank gives it enough legs to get in the swing of things and I can even blast a little without turning on the additional especially if I got to flip parts etc.
Depending on how busy and sensitive it was 5 hp on a big jug could skate with 2 men in a small shop for auto body, 10 will run quite a gang minus sandblast. Half a dozen men possibly.

 

[sberry]

Then I can manually keep the alternate using each compressor so they wear evenly, run one as a lead for one oil change interval then swap to the other as lead...


THE only thing about that I wasnt crazy about was I would rather not have both pumps starting at once....

I agree about the start at once, one at a time and using the switches to set one a bit low is what I do and easy.
The thing about these duals,,, they were hi quality units, meant to run a long time, usually plant or some form of continuous air. The maintenance in a small shop is about a non issue if it isn't running in the dust, bring air from outside and might shield the motors so they are not sucking up body dust. You could alternate by the year here.
Is this unit to replace an existing one or in anticipation of work? If its way in the future would make it work and go from there and add pieces as needed. Make 1 unit run today and add the next as it comes easy.

 

[jonjon1]

How much work are you planning to do? A large tank really stretches out the duty cycle. I got 200 gallons and use 3 hp and can finish what I am doing before air is an issue.
I can be thrifty and do auto body from 3 at 80 gallons but its really a job for 5 hp. The added tank gives it enough legs to get in the swing of things and I can even blast a little without turning on the additional especially if I got to flip parts etc.
Depending on how busy and sensitive it was 5 hp on a big jug could skate with 2 men in a small shop for auto body, 10 will run quite a gang minus sandblast. Half a dozen men possibly.

I have 230 gallons right now, BUT I am going to be getting rid of the rest of the storage and just using this one compressor to make things a bit more simple and save a bit of space..

I can have 2 da's running at once and the blast cabinet, so each da is just under 10 call them 8 continuous, and the blast cabinet is around 18, so when that is happening both pumps will be running and there won't be anything left over to fill a lawn mower tire...

Thats where I got my idea to run twin 5's, they tend to keep up, and with 1 7.5 we would all have to stop every 5 minutes or so and let the tank build up, you can not know the aggravation of not having enough air until you put in a 5 hour day sanding a body 10 minutes at a time. Me and my 2 sons work in the garage at the same time, so for example they will be da'ing a car while I am blasting all the bumper brackets, etc. They are sitting there on roller stools with full respirators on and waiting for air, it *****... You kind of just want to get it done...

 

[sberry]

Yes, you have work waiting on air is a real issue. DA is more greedy, about 15 cfm. It would be a race for me to get it done if I was paying for much wait time.
Having some background really helps, so many hobby types have the demand factor and duty cycle skewed and time and or time and money make things a completely different factor.
I just mentioned in another thread about thw difference between a 210 welder and the IM230. The Im is 2x the machine, this unit you are building will be 2x and something in an earlier post, do not mess with the pressure settings. You will not save any money turning it down and the point here is to store as much energy as possible with the fewest duty cycles.
175 psi.

 

[sberry]

You can likely employ enough work planning to lay off a DA when running a blast cab and if it was system critical include the old comp to come on for blast but,,, would also consider enlarging the blast to meet available air and shift some work around to speed it up and reduce manhours.
I see one of the restorer shows on TV and they yak on about blasting but they over quote the man hours there but were way under on assembly. They were too cheap anyway.

 

[sberry]

I can make 28 cfm electric and 35 more with a gas drive in addition. I sandblast a couple small tractor tire rims, 32;s or so in 20 mins. I use a fair nozzle, couple hundred # of sand maybe and with one 5 minute stop don't even bother to hook up the engine.

 

[sberry]

Hook the old critter to come on with the blaster and put a bigger nozzle in it.

 

[md21722]

By using dual pressure switches they will not start at the same time. Based on the documentation for that switch, the voltage would depend on what model you ordered. For example, you could buy a 230V.

 

[jonjon1]

Hook the old critter to come on with the blaster and put a bigger nozzle in it.

I am building this thing to get rid of all the other units, I have a 2 year old IR 185 trailer mount, with a JD 4cyl Diesel, lol, it makes 185cfm NON STOP, we run 3 jrd30's at the same time!!! But taking it home and running it in my driveway is not an option, my wife may have a stroke, bad enough I use a mc135 to move snow at the house, lol...


As far as moving around work, I like to be in there when the kids are in their working with me, they are almost 15 and 17, and I trust them, but 1 enjoy working with them, and 2 the first time they run in the house covered in blood and paint dust, I am flirting with the wife/stroke thing again...

They are good boys but, I could picture my youngest saying "hey lift me up with the excavator so I can take a selfie way up in the air" and my oldest saying "ok"... (ask me how I know this, I pull in the driveway and my 14 year old is 30feet in the air standing on the bucket of my cat 235 with a selfie stick!!! I kept my cool, I parked walked over to my other son who wa sin the cab, told him to carefully get out and I jumped in and let him down nice and easy...

There was h#!! to pay that day, I erased the pictures, hid all the cat keys (problem is all the machines have the same keys)... Surprised I didnt have a stroke, kids just don't think about stuff...



ANYWAY, I like to be in there when we are working, I have been moving all my "personal" work to the house, I have a detached parking garage "toy box", and I am using my 2 car attached garage for restoring the cars and playing.... ITS a chore, but I am getting it ready and comfortable to work in little by little.. This compressor is part of it, right now, I have a 5hp i built a while back, a 6.5 hp outside in another building, and another small duplex I plug in, its a pita... I just want one unit I never have to play with again...

 

[jonjon1]

By using dual pressure switches they will not start at the same time. Based on the documentation for that switch, the voltage would depend on what model you ordered. For example, you could buy a 230V.

So the eaton mag starters use 230 for the coil power correct? if that is so, its easy to wire, in the havac field we run into controls that make their own coil voltage with a sd trans, so you have 2 separate controls with tt terminals that when closed activate the device, so you cant mix them with multiple controls on a single switch or relay since you have 24ac coming from two transformers... Well you can but you need more components...


SO if the coil in that starter is 230 I am good and can order that alternator???

 

[Packard V8]

2- Brand Spanking New Ingersoll Rand 2475 T30 pumps

store as much energy as possible with the fewest duty cycles. 175 psi.

Are these high pressure or high volume T30s? The high volume have two equal size cylinders and work best in the 80-120 PSI range. I saw one burned up trying to make and hold 175 PSI.

jack vines

 

[jonjon1]

1 big and 1 little cylinder... I normally run the compressors around 150 shut off, always sounded easier on the compressor and never noticed too much storage difference...

 

[jonjon1]

OK, so for the duplex control I think I have it figured out, for anyone who is looking in the future, (I should have this compressor up and running in a couple weeks so just check back to make sure I lived, lol)

http://www.macromatic.com/literature/catalog/alternating-relays/#?page=2 its a $35 relay at zoro tool and looks to do what I want it to do... # arp240a3r

I will wire just like the diagram with 2 adjustable NO pressure switches, and 2 motors, looks pretty simple as long as my starters have 230v coils...

This will work exactly how I want it to, I spoke with the company they say it is a normal use for them.
When the lead switch closes motor 1 will power up, then when the lag switch closes motor 2 will power up, and when they reopen the motors will power down. AND on the NEXT cycle motor 1 will alternate to the other side so the motor that worked with the lead switch the last cycle will now be the lag motor.... SIMPLE, lol...


SO this saves a bunch of money, a duplex control from siemens or where ever is $750, 2 eaton mag starters and this control with the hub will $250-350 max, depending what you spend on the starters, they are $100-150...



PS- fyi, macromatic is about the best control company out there, you call tech support they answer first ring, 5 year warranty minimum on their stuff, prices are right, and they make most of it for the rest of the industry....

 

[Finky198]

I had it on a 50amp with 8' of 6 guage and it would trip at least once a day after running a few cycles, now that I put it on a 60 amp breaker with 4 guage it has tripped twice in 3 months. It usually just trips the 100 amp.. It starts fine when it's unloaded 50 psi or less but if it at 100+ with the lights and a few tools running it pretty easy to go over the 100amp circuit and trip the main

I known I need a bigger panel hey it could be worse
It is pretty hilarious how big the 7.5hp motor is

 

[jonjon1]

I had it on a 50amp with 8' of 6 guage and it would trip at least once a day after running a few cycles, now that I put it on a 60 amp breaker with 4 guage it has tripped twice in 3 months. It usually just trips the 100 amp.. It start fine when it's unloaded 50 psi or less but if it at 100+ with the lights and a few tools running it pretty easy to go over the 100amp circuit and trip the main

I known I need a bigger panel hey it could be worse
It is pretty hilarious how big the 7.5hp motor is

maybe a slower breaker?

Is your 7.5hp a 3520rpm? The WEGS are just BIG, lol

 

[Finky198]

maybe a slower breaker?

Is your 7.5hp a 3520rpm? The WEGS are just BIG, lol

Yes it's the 3520rpm.
Have you thought about going up to 7.5hp vs the 5hp. Our system as it sit is the 2475 80gal with a 40gal surge tank putting out approx 24cfm. As you said your looking to produce in the 34cfm range with 2x 5hp units. I know 24 is not really enough for our needs running 1 lg and 1 sm grinder is enough to bog down the system, being the main reason I would like to add another 2475 80gal yielding 50ish cfm. I would make sure you really over estimate your needs if you need 2x DA at 10-15 cfm each plus your sand blaster at 18+ probably closer to 24ish then your draw is already over the 34cfm which is the theoretical output not the real world output. Just food for thought you

 

[jonjon1]

Well, the most air we ever use in the garage is 2 air tools and the sand blaster, the da's I have only use about 9cfm each at MAX, and they are turned down to about 60% for what we are doing, actually the snap-on my oldest likes to use only uses like 4cfm... The hutchins I have a couple of (4550's?) use around 10 all in at 90psi...

BUT the blast cabinet is sucking some air, so when you figure it out say 17-18 for the blaster, then 15 for the 2 da's, thats 32 ish, I am confident the 2 5's will be perfect, running a 7.5 is gonna dim the lights, lol... I was thinking about it, but I would rather run the lower rpm, lower power, and have JUST enough got the worst case scenario... My math gives me 34.0cfm at 90psi, with the sheaves I have... I was thinking of doing 1 at 7.5 and the other at 5, but that will be weird for the alternating, figured just do it this way and be done with it..

PLUS my sup panel in the garage is limited as it is, lol. I am going to NOT weld or use the lift when the compressor is running, lol...

 

[Finky198]

Same here on the welder Sounds like your on your on your way to a nice setup

finger crossed so far the plasma cutter / air compressor are just under our power limitations

 

[md21722]

It does sound like you'll be having a nice setup. I do wonder about the reports of tripped breakers and CFM though. Generally CFM is an average over an 8 hour work day or whatever, whereas full load is 4-5X as much. For example, I have a 0.5HP die grinder rated at 4-5CFM (23SCFM free speed) and an angle grinder rated at 37CFM. The die grinder CFM is obviously referencing the "average" where as the true SCFM is somewhere around 18CFM under load. As for tripping breakers, by code, with a thermally protected motor, you can run 1.25 X the max load amps wire size and 2.5X the breaker. So a 23A 230V motor would be 23x1.25 = 28.75A (10 gauge wire) and a 23x2.50 = rounded up to 60A breaker. The same would not hold true for a resistive load, etc.

 

[jonjon1]

OK, so I have the electrical pretty well figured out, EXCEPT for the pressure valve setup and unloading....


How would I plumb the unloaders and pressure switches, since at different times the unloader for the lower lag pump will be running to the lead pump????

 

[sberry]

I like a couple smaller motors. 5 hp is plenty. I am on rural, I got 400 service and wire as big as a thumb but I keep my old 3 hp as the primary just due to motor starts, its a tiny bump.
I agree your per tool load estimate is low but averaging makes up for some of it. Since they will both be on line set them close to each other. Run one for a few years till its getting tired and then move it to the back seat and use the other one as a primary.

 

[sberry]

If one of these units works while it has 50 on it but trips with 100 starts there is something wrong with check valve or unloading.
I agree and it can have a 60 but there is probably something amiss if it trips it. I have seen a lot of units ran 10/30 and never trip.

 

[md21722]

OK, so I have the electrical pretty well figured out, EXCEPT for the pressure valve setup and unloading....


How would I plumb the unloaders and pressure switches, since at different times the unloader for the lower lag pump will be running to the lead pump????

Dual stage pumps commonly have built in head unloaders so there is no plumbing.

 

[jonjon1]

I think they have to be plumbed to the pressure switch?

 

[md21722]

They're often centrifugal and do their job when the pump comes to a stop. I don't have your pumps in front of me, but I looked the manual for them and unless I missed it, they do not require external unloading. If you look at pictures of many of the Champion or other splash lubricated dual stage pumps you will see some small lines running across the compressor. This is the function. In pressure lubricated models you may see a bunch of lines as well, and part of that function is to keep the heads unloaded until oil pressure builds up.

 

[Finky198]

If one of these units works while it has 50 on it but trips with 100 starts there is something wrong with check valve or unloading.
I agree and it can have a 60 but there is probably something amiss if it trips it. I have seen a lot of units ran 10/30 and never trip.

It really is just an issue of not having a large enough Wire coming from our main panel to the sub panel. Only having 100 amp service when what we really need 200 amp service

Just a basic case of supply and demand

Our plan for the next season is runing a 60 foot trench with 8" green sewer pipe and putting in 2 gauge wire to a new 200amp sub panel, along with an Ethernet, telephone, and coax runs

 

[jonjon1]

They're often centrifugal and do their job when the pump comes to a stop. I don't have your pumps in front of me, but I looked the manual for them and unless I missed it, they do not require external unloading. If you look at pictures of many of the Champion or other splash lubricated dual stage pumps you will see some small lines running across the compressor. This is the function. In pressure lubricated models you may see a bunch of lines as well, and part of that function is to keep the heads unloaded until oil pressure builds up.

So the 2475s I have have a small line from one head to the front bearing area where the shaft exits the block and the flywheel is mounted, then there is a tapping on the inside of the first stages head, that is piped to an unloader.

I only have the tank used tank and a box of parts that came with it, the pumps are new, never been hooked up so they dont have any of the fittings in the heads...


https://www.platinumbidauctions.com/Auction/151/AuctionLot/5851
I was looking at them pictures trying to figure it out...

 

[jonjon1]

I tried to tall IR and ask what the story was but the guy who knows anything about compressors must be off today because it must have been the guy I talked to's first day...

Anyway, I ordered some stuff that I am just replacing from what is in the box of parts that came off the original 5hp duplex.
2-80psi safety valves, a 200psi safety valve, and 2 check valves, I have a bunch of these things, but of course not the ones I need, I am changing the plumbing a bit.

Originally the pumps went to the receiver via the center top tapping, I am now going to run them into side/end tapping, I have all the bushings and some nice apollo ball valves that will work nicely, also called up Parker and they are making me a pair of 3/4" mnpt stainless braided lines, supposed to be good for 1200psi and 480degrees, he said they used them on compressors before and never had an issue... I am going to have him make all the little lines also...

I also bought an SEM hot rod black kit to spray the tank with, I am going to power wash it degrease it, and DA it down, this weekend, then paint it right outside, since sunday it is supposed to be in the 60's outside, should work well enough...

I think it will look good matte black with orange decals...

It is getting expensive though, lol.. I owned the pumps, not sure what they cost me, it was a while back and I owned the tank, again, no idea what it stands me, maybe $300 for the 2 pumps and the tank, I cant see myself spending much more than that, and the starters were bought on sale, like $100..

AND now I spent about another five hundred or so on belts, paint, oil, air filters, ss tubing, valves, and the alt control... I STILL need 2 l1430t's, which will cost me around $600-700... PLus I need psi switches.. (IF anyone knows which ones I should buy please let me know..., I am thinking square D, and I want the ones in a real box that can be surface mounted...

SO I am going to be into this thing for under $2000 all said and done... It will be all brand new and I am thinking that is a pretty good deal, about half price from going to buy a new one....

 

[sberry]

Its got large enough wire to trip the breaker, a bigger wire will make it trip faster.