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

[md21722]

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

Good idea, but I've been told that you want to separate data lines away from power lines so they don't absorb any noise from the power. One wider trench with two separate conduits may be in order. I don't remember the requirements off hand, just know that they exist...

 

[md21722]

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...

I get it now, and don't have any initial ideas on how to solve this issue. In the picture, you can see that they are connecting the unloader line directly to the pressure switch for each. You could do this if you scrapped the alternator idea. Or alternatively used 4 sets of pressure switches... But I'm wonder if there's not a better way. Using pumps that don't have centrifugal unloaders there may not be.

I don't see any reason to with Square D. What you need is something adjustable, maybe present from the factory, but adjustable. I believe something from Condor Hubbell/Furnas may be in order.. Square D makes excellent stuff, but I'm not sure its applicable to your situation.

 

[jonjon1]

I get it now, and don't have any initial ideas on how to solve this issue. In the picture, you can see that they are connecting the unloader line directly to the pressure switch for each. You could do this if you scrapped the alternator idea. Or alternatively used 4 sets of pressure switches... But I'm wonder if there's not a better way. Using pumps that don't have centrifugal unloaders there may not be.

I don't see any reason to with Square D. What you need is something adjustable, maybe present from the factory, but adjustable. I believe something from Condor Hubbell/Furnas may be in order.. Square D makes excellent stuff, but I'm not sure its applicable to your situation.

The only had an unloader on one of the pressure switches, the other switch has no unloader, the line goes from each pump to a tee and then to the one pressure switch...

Not sure if that is the lead or lag pressure switch...

BUT I am thinking if the unloader is on the lead switch the lag pump will have to start "loaded", if it is on the lag switch then it is going to be venting when the lead pump is trying to build pressure....

UNLESS they had the lead and lag switches with the same shut off pressure, so if both pumps shut off at say 150 psi, then the single unloader will work I guess...

ALSO having them teed together isnt the lag pump always going to start loaded? Since the lead pump is pumping air into it through the tee? There are no check valves in the pictures or in my box of parts...


As far as the 4"style Square D pressure switches, I have a few of them, and I NEVER replace them things, I know they are $100 each BUT they just last for ever, you never change a psi switch again, they do make cheaper ones also, but I will tell you and time I do a well switch, I use D to replace them and then you never do one again....

 

[jonjon1]

I think I am going to go with electronic solenoids on for the unloaders...

When you unload the line going from the second stage head to the tank, does that also unload the first stage piston?

 

[Finky198]

I have used and had good look in the past with the Square D style pressure switches especially on sprinkler systems not on air, but I would assume that they are just as reliable.

Going to say seems like quite an expensive project, but if you're under the $2000 range you're at just about what we spent on the compressor new. So you're getting 1 1/2 times the CFM result so not a bad investment. I would be in about 3500 if I can find another one on CL or get a good deal else where. The IR 2475 series is a really nice units

 

[redmondjp]

I think I am going to go with electronic solenoids on for the unloaders...

When you unload the line going from the second stage head to the tank, does that also unload the first stage piston?

I'm not sure about whether the primary stage is unloaded on your pump or not since I am not familiar with it.

However, I wanted to throw out a really simple idea borrowed from low-cost compressors for your unloader. You could also use this idea temporarily while you figure out something else. It's a tiny air leak in the discharge line from the pump to the tank check valve. An orifice, somewhere in the 0.010" to 0.015" range I think.

Yes, this makes for a tiny leak while the compressor is running, but it is so small as to be ignored. However, after the compressor turns off, it bleeds off the pressure in the discharge line in a few seconds.

They also make unloader valves that operate in a similar fashion but seal off the orifice while the compressor is in operation:

http://www.cdivalve.com/products/valves/air-compressor-valves/unloading-check-valves

 

[Strouty]

Three pages and still no pictures, WTF???? My imagination only goes so far, I am going to go look at some tool **** now.

 

[jonjon1]

I'm not sure about whether the primary stage is unloaded on your pump or not since I am not familiar with it.

However, I wanted to throw out a really simple idea borrowed from low-cost compressors for your unloader. You could also use this idea temporarily while you figure out something else. It's a tiny air leak in the discharge line from the pump to the tank check valve. An orifice, somewhere in the 0.010" to 0.015" range I think.

Yes, this makes for a tiny leak while the compressor is running, but it is so small as to be ignored. However, after the compressor turns off, it bleeds off the pressure in the discharge line in a few seconds.

They also make unloader valves that operate in a similar fashion but seal off the orifice while the compressor is in operation:

http://www.cdivalve.com/products/valves/air-compressor-valves/unloading-check-valves

Thanks I never seen them before, I wonder how reliable they are?

 

[jonjon1]

Three pages and still no pictures, WTF???? My imagination only goes so far, I am going to go look at some tool **** now.

I took some pics us pressure washing the tank, it was pretty gunked up with greasy slime, I have a 6K psi hot washer and still had to use degreaser!!!

I'll load them up today for you , sorry..

 

[redmondjp]

Thanks I never seen them before, I wonder how reliable they are?

If you read their website, they have been making compressor controls for most compressor OEMs since 1963. So I'd say that they probably know what they are doing.

 

[md21722]

I forgot these existed. I've never used one but never heard about problems with them. This is a nice easy solution.

 

[jonjon1]

OK heres a couple pics, I took some more of the pumps but they didnt come out, I will do more tomorrow..

I hot washed it and the paint on the tank is nice, BUT I want to paint it anyway, I am using sem hot rod black kit, and I am going to do the pump perches gloss black (some decent oil resistant paint I have, I think it will hold up better than the matte incase oil gets splashed on it)....

The air dryers are new, a 15cfm and a 25 cfm, nothing fancy, just a couple IR refrigerated driers....

 

[Strouty]

Much better.

 

[jonjon1]

So I did a bit more, I removed all the fittings from the tank (of course the 1 2" inverted sq drive plug was a pita. The tops, bottom, and other side plug I removed with the 4ft pipe wrench and they came out like butter, BUT that stupid plug had to be drilled, cut, and air hammered, and I have the proper lug to remove it, it was just too stuck and soft, the sq drive with a 3ft bar on it just rounded the drive, no big deal took me about 15 minutes to get it out...


After the 2 side plug swere out I was able to lift the tank onto a pair of rolling pipe stands with a 1" steel pipe going through it, so I can spin it. I then put about 50 gallons of hot water with a couple gallons of zep degreaser to get some of the old oil out of there, its clean enough inside now, I then ran a heat gun through the top hole to dry it out a bit, but its foggy, wet, and raining here, so no much use right now...

I also put all the plumbing together for it, I had 80% of it, but had to buy a bit.. I am going to say with all the braided hose, brass fittings, a 3/4" IR regulator filter combo, ball valves, check valves, shuttle valve, cold start valves, etc. There is easily over $1000!!!! And that is just plumbing the tank and air dryers LOL...

I think I under estimated this project!!! I owned the tank, Brand new pumps, and brand new starters, and I got all of that for a REALLY good price, other wise I would have been better off buying a brand new unit from the store, lol..
2475 pumps $2000 for a pair
mag starters $300
tank $1500

I bought the motors for $575 a pair, $1000 on plumbing, $300 on electrical, $200 on paint, and I really didnt even start putting it together yet, lol...

BUT I had a buddy of mine over here that just bought a 5hp single with an air dryer (CP) and he spent $2000 used (private owned like brand new), so if I am into this system for $3000 with the air dryers I will feel good about it...

 

[redmondjp]

Thanks for the update! Yup on everything you have said.

A similar thing happened to me with a pressure washer in my possession. It's a big one: 4Kpsi 4.3GPM, with a General belt-driven pump powered by an 18HP V-twin Briggs Vanguard engine. A couple of years ago I went down to the pressure washer parts store because I needed a new bypass valve ($257). After buying some hose fittings, a turbo nozzle (best PW accessory EVER), an angle adapter for the gun tip, and a liquid-filled pressure gauge, I walked out of that place in shock, with an $800+ charge on my credit card!

Keep us posted - that will be an incredible setup when you get it done.

 

[jonjon1]

OK, I am on a roll, lol. I woke up today and the sun was out, it was only around 50, but I figured there isn't going to be many more days like this, so I sanded it down, and after a few hours, I realized ITS AN AIR COMPRESSOR, lol.. So I hurried through the da'ing process, wiped it down with tsp and started mixing the paint. I primed it, then I painted the tank flat black with no shine clear coat, then the framing I painted matte black with the matte clear, and the pump mounts, brackets, and cages are painted high gloss oil resistant black...

It looks good with out going too crazy sanding, its going to get scratched and beat up, so I dont know what I was thinking, lol. BUT what ever, hopefully it hold up well...


ALSO the motors came, 180lbs of baldor in the mail, lol... I am still waiting for the alt control, and a few other plumbing parts, the new belts came, a gallon of royal purple oil, and the new check valves, safety valves, etc... Should have it pretty well together before !!!!

 

[md21722]

Looking good!

 

[Charles (in GA)]

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

Something is seriously wrong here. A full 7½ hp compressor draws about 32-33 amps running and produces about 24 CFM. Doesn't matter what brand, what motor, if it is real 7½ hp, that is about what it produces and burns in power. Mine draws up to 190 amps for a split second on startup, I think I have it on a 50 amp breaker and it probably would run on a 40 but I never tried it. I used 6 gauge copper wire to supply it.

If you are having trouble with tripping breakers, the pump it loading up the motor too much, either wrong pulley sizes, or air leaking back into the pump outlet and loading it up on startup. Something is wrong and this needs to be looked at.

Charles

 

[jonjon1]

So, a friend of mine just stopped buy to borrow a cage puller (he also restores cars as a hobby) and I showed him the compressor and pile of parts, so NOW he wants to build one!!! BUT he said it has to be twice as good as mine, lol...

Since I have been doing tons of compressor research, pulled up some websites I have saved..

2 of these http://www.ebay.com/itm/10-HP-Kello...153178?hash=item19de809d1a:g:wcoAAMXQCgpRywmS
2 of these http://www.ebay.com/itm/L1510T-7-5-...678140?hash=item3cf5f788fc:g:XMUAAOSw-W5U0~g3
1 of these http://www.compressorworld.com/200-...opplate-grasshopper.html#sthash.eyRL4HaS.dpbs

Figure 625 rpm ish would be about 65cfm!!! He would NEVER need that much air, lol just that kind of guy, he has a 5hp and a 7.5hp now and never runs out of air, his compressors are still worth something, he said "I can sell my 2 units for $2000, and build that one for $5000", I explained its a lot more than just pumps, motors, and a tank, he will need a pair of base plates (he will make them himself), belt guards, starters, plumbing, psi switches, sheaves, belts, a half dozen valves, etc..

He said hes going to look into it, he will build something like that JUST to "one up" me, but its fun to watch, lol...

 

[md21722]

He forgot the refrigerated air dryers.

 

[jonjon1]

He forgot the refrigerated air dryers.

Well he has a pretty nice air dryer, its a SMC rated for around 75cfm, he SCORED it on c-list, they listed it as 3 phase and it was on there for about a month for $1500, they dropped it to $1000, he was researching it and seen it was a single phase, went and looked at it offered them $400 and they took it!!!! It was maybe 6 months old!!!! Lucky bastid...


He texted me a bit ago, he said he can get kellogg clones for $650 each that are the same thing. I told him to just buy one all done..
http://www.ebay.com/itm/NEW-CHICAGO...242bea7&pid=100009&rk=1&rkt=1&sd=281835207873

you can get them for $4K shipped , 7.5hp x 2 almost 50 cfm, and it will last forever in a hobby garage...

 

[md21722]

I think shipping is extra. Maybe tomorrow he will realize the 12.5 HP worth of compressor he already has is plenty. If not I would suggest he stop screwing around with that cheap stuff and go with a duplex from Saylor Beall, Champion, or Curtis.

 

[Finky198]

Something is seriously wrong here. A full 7½ hp compressor draws about 32-33 amps running and produces about 24 CFM. Doesn't matter what brand, what motor, if it is real 7½ hp, that is about what it produces and burns in power. Mine draws up to 190 amps for a split second on startup, I think I have it on a 50 amp breaker and it probably would run on a 40 but I never tried it. I used 6 gauge copper wire to supply it.

If you are having trouble with tripping breakers, the pump it loading up the motor too much, either wrong pulley sizes, or air leaking back into the pump outlet and loading it up on startup. Something is wrong and this needs to be looked at.

Charles

There is nothing wrong the compressor its a brand new IR2475 7.5 ... The big prob is that I have it on a 100 amp sub panel that also runs other things including shop lights, outlet, and tools which easily draw a 100amps then the compressor kicks on and draws 100+ amps for a split second and trips the main.. I need a bigger sub panel and larger wire to feed it


I thought about building a compressors setup as well but soon realized it is very hard to save any money doing so. I wanted to install/build something around the 50 CFM mark, but it's Much more functional to have two separate 24 CFM IR units when the time comes. I can just install a 2nd one right next to it and be in for around the same money but with less of a headache then building the custom unit minus the cool factor

 

[jonjon1]

Well Finky I figured out how to get them to run together, lol...

For the control you need..
this relay http://www.zoro.com/macromatic-alternating-relay-dpdt-240vac-10a-8-pin-arp240a3r/i/G3600256/
this hub http://www.zoro.com/dayton-relay-socket-standard-octal-8-pin-15a-5x852/i/G1753902/?q=G1753902
and this box http://www.zoro.com/square-d-enclsr-metllc-528inhx363inwx331ind-9991ue1/i/G7562834/?q=9991UE1

thats pretty straightforward part of it...


NOW to plumb the unloaders...

2 options...

1-
you would need 2 - parker # 04F20O1106ACF4C15 , thats a 1/4", 300psi, normally open, 2 way, 240vac solenoid valves. Simply disconnect the unloader line from the pressure switch and hook it to the inlet of the solenoid valve, put a 1/4 muffler on the exhaust of the valve. Then wire it to the switch side of the pressure switch so its only live when the motor is running...

This will also give you a low amp cold start since it takes a couple seconds for the valve to close when the motor starts...


The other way to handle the unloading makes you have to tie the compressors unloading lines together... you need http://www.amazon.com/dp/B00S84W4X6/?tag=atomicindus08-20 that shuttle valve and you will only use the unloader valve from your lead pressure switch, plumb the tanks to the inlets and the unloader to the outlet...


I am doing both, kind of like back up, lol..