DIY full size air compressor - am I mad?
Discussion
Gary C said:
Super Sonic said:
"full size"? I once worked on a building site putting diesel in stuff and the compressors were up to portakabin size.
Well, if you want to play that game 
Our air systems at work use 4 3m x 3m receivers then into two 20m long by 4m diameter receivers from 6 oil free screw compressors, and thats just the instrument air.
Each of the eight diesel engine start systems use 3 reciprocating compressors and 4 1m x 3m receivers then the general service air system uses four more big (2 are portakabin size) screw compressors and 3m x 3m receivers.
Thats 34 compressors in all with a huge reservoir of air to keep essential systems running if we loose site supplies.
Then the 50 or so fire systems each have their own compressors to run the air detection for dry deluge valves.
And then we have the Forced Air Compressor system. This compressor runs off a 3.3kV motor and has a four stage centrifugal compressor with wheels the size of big dinner plates. Only runs up to about 14 bar but the CFM is huge and is used to purge the reactor of CO2 and fast cool the turbine if we want to work on it as soon as possible after a trip.
Then there are the various hydrovane and test compressors around the site.
Edited by Gary C on Saturday 7th August 14:06
Gary C said:
But with experience of all that kit
I would strongly recommend ensuring that the relief valve on any second hand receiver is at least checked for freedom of movement before running the compressor.
The stored energy in any receiver is big enough to cause serious harm.
Yes, that's literally the first thing I checked. I haven't had time for a proper going over yet, so I don't even know whether I need to change any fittings. I use XF connectors on my existing compressor and I think this one was hard-wired - I also have the reel of air line that you pull out to fill your tyres. Sadly no tyre inflator was seen in the bag, but I already have a PCL Mk4 digital inflator in my arsenal. With 4 cars, a motorcycle and garden machinery, none of which have tyre pressure monitor it's proved a worthwhile purchase.I would strongly recommend ensuring that the relief valve on any second hand receiver is at least checked for freedom of movement before running the compressor.
The stored energy in any receiver is big enough to cause serious harm.
Gary C said:
But with experience of all that kit
I would strongly recommend ensuring that the relief valve on any second hand receiver is at least checked for freedom of movement before running the compressor.
The stored energy in any receiver is big enough to cause serious harm.
YepI would strongly recommend ensuring that the relief valve on any second hand receiver is at least checked for freedom of movement before running the compressor.
The stored energy in any receiver is big enough to cause serious harm.
On an industrial site its a legal requirement every 24 months (as you may well know
)Gary C said:
mikey k said:
Nice size system!
The largest we look after has 3400kW of compressors to make air bags.
I'm guessing yours is on a power station?
Yep, its a UK nuclear station and we tended in the 80's to go over the top The largest we look after has 3400kW of compressors to make air bags.
I'm guessing yours is on a power station?
Money no object
Energy consumption not an issue either
Okay, so I managed to find some time to look at what I've got last night.
The receiver has a 1" BSP outlet in which there's a reducing fitment that takes it down to a 3/4" thread.
There's a pressure switch to control the motor, and there's a marking on the dial suggesting that it's set to 150 psi. There's no glass or plastic face cover on the dial.
My little Wolf Compressor has a regulator with two outputs but not nearly the same flow rate, so I guess I probably need to buy a regulator/filter with either a 3/4" or 1/2" input to handle the 14cfm flow rate. Or even higher if I don't mind the pump not being able to keep up.
And then I need either a single phase motor or a 3-phase inverter. I see the new versions of the same compressor come with a single phase motor, so this would be the ideal solution but much more expensive than an inverter. Am I missing anything?
The receiver has a 1" BSP outlet in which there's a reducing fitment that takes it down to a 3/4" thread.
There's a pressure switch to control the motor, and there's a marking on the dial suggesting that it's set to 150 psi. There's no glass or plastic face cover on the dial.
My little Wolf Compressor has a regulator with two outputs but not nearly the same flow rate, so I guess I probably need to buy a regulator/filter with either a 3/4" or 1/2" input to handle the 14cfm flow rate. Or even higher if I don't mind the pump not being able to keep up.
And then I need either a single phase motor or a 3-phase inverter. I see the new versions of the same compressor come with a single phase motor, so this would be the ideal solution but much more expensive than an inverter. Am I missing anything?
I bought a 5hp, 60 gallon (US so about 220L) upright compressor for the house and one for the hobby shop. The main reason is that I wanted to run air tools and they both do a good job as long as you're not running something like a DA sander. I can paint a complete car with a HVLP gun and have it kick on maybe 3-4 times.
They don't use a lot of space, basically like having a guy standing in the corner. I think I paid about $250 for the one at the shop and i bought it about 16 years ago. I have an 80 gallon sitting outside that needs a motor. I will probably press it into service once I buy a new motor.
They don't use a lot of space, basically like having a guy standing in the corner. I think I paid about $250 for the one at the shop and i bought it about 16 years ago. I have an 80 gallon sitting outside that needs a motor. I will probably press it into service once I buy a new motor.
LunarOne said:
And then I need either a single phase motor or a 3-phase inverter. I see the new versions of the same compressor come with a single phase motor, so this would be the ideal solution but much more expensive than an inverter. Am I missing anything?
Your might be able to rewire your motor to single phase as some can. I have a second 60 gallon compressor at the house that came with a blown motor. I pretty much replaced, the motor, pressure switch and the pump for about $400, just using the tank. A bit of an update on my freebie from Sainsbury's Clarke Air Industrial VE15A150 compressor fitted with 3hp 3-phase motor.
After weighing up all the options including building a rotary phase converter and buying a variable frequency drive 3-phase inverter, I decided that I wanted the compressor to be able to start and stop by itself as the air pressure in the receiver rises and falls and I didn't want the wastage of a rotary phase converter that I would have to start and stop. I decided that I'd get on to Clarke and enquire what motor they use in the single-phase version of the current VE15C150 comes in both single-phase and 3-phase variants. Once the motor was identified, I decided to buy it from them (£180) along with a 3/4" ball valve (£14) for the receiver outlet and three rubber anti-vibration feet. I thought I'd put the ball valve in the reducer ring which brings the 1" outlet down to 3/4". But it turns out that BSP threads are weird, and for some reason unfathomable reason, a 1" thread is actually called 3/4" BSP thread and you have to keep subtracting 1/4" to get the name of the product you want. No idea what's going on there. What this meant is that I had to remove the reducer ring from the receiver and fit the 3/4" ball valve directly to the receiver outlet. And then I put the reducer ring onto the outlet of the ball valve. So now the outlet after thee valve measures 3/4", which means it'll take 1/2" hose fittings.
With the compressor now fitted with a ball valve, it was now time to remove the three-phase motor, but first I had to remove the cage that protects the pulleys. Or rather, the cage that protects you and me from the pulleys! After undoing the four bolts that mount the motor foot to the top plate and removing the motor power cable from the pressure switch, I was able to take the motor off and plonk it on my workbench - the building of which was a project I began in early lockdown last year.
The new motor came without a pulley, but it needed the same size pulley as the original, so I thought I'd undo the grub screw holding the pulley onto the output shaft and slip it off. Or so I thought. Nothing I could do would let me get that pulley wheel off the shaft. I tried levering it off with a crowbar, I tried making wooden wedges to get it off. Nothing worked. In the end, I ordered a 3-leg puller, and with the help of my impact driver, was able to remove the pulley wheel without any trouble. I guess the old adage of having the right tool for the job still holds.
I was then able to install the pulley onto the new motor, although it required a few gentle whacks with a rubber mallet and a large socket to get it to slide into place on the shaft.
I then shoved the contacts from the motor straight into a mains socket, and flipped the switch. Would the motor run in the correct direction? Would it blow my circuit breaker with too much inrush current? Nope, the motor burst into life, but there was a problem. There was a weird pulsing vibration from the drive belt, so I flipped the switch off quickly to investigate. It turned out that despite thinking I'd tensioned the belt sufficiently, it wasn't tight enough. Worse still, the motor had moved slightly in its mounting bolt slots, and the drive pulley wasn't properly aligned with the compressor pump pulley. Off came the front of the guard, and out came the puller. A few seconds later everything was lined up properly. I also used a piece of wood wedged between the motor and pump to get the tension right. Once I was sure everything was lined up and taut, I re-tightened the motor mounting bolts.
I then flipped the mains switch and let the compressor start to build pressure. The pressure gauge rose fairly quickly to 2 bar, 3 bar, 4 bar when suddenly there was a sound like an explosion and there was liquid pissing out of the bottom or the receiver onto my garage floor. I knew that there was a drain fitting at the bottom of the compressor, but I hadn't physically checked it. I figured that I'd hear air escaping if it was open, and that if the pressure rose, it must be sealed. But it seems it was open, but blocked by something. In fact, it's just another outlet positioned at the bottom of the compressor to drain condensation. I don't know how it was rigged in situ, because I doubt anyone at the Sainsbury's petrol station physically crawled on hands and knees to vent it periodically. I'm guessing there must have been a hose fitted which led to some remote vent valve on the outside of the tyre machine pumping machine. And I doubt it was used judging by the amount of oil that found itself lubricating my garage floor.
The vent pipe is much smaller than the main outlet, but a 10m length of the air hose with threaded ends that I rescued at the same time fitted perfectly, and I put a female XF connector at the other end of the hose and connected it to my blow-gun. That took care of all of the open outlets, and again it was time to see if the compressor would get up to its operating pressure of 10 bar. But before I wanted to risk that, I wanted to wire up the motor to the pressure switch. That way I'd have a better way of switching off than at the wall, and I'd also have the safety of the system shutting itself off when it got up to pressure.
Once wired up through the pressure switch, I discovered that it kept tripping out and flipping its own switch to the "off" position when the compressor got to about 3 bar. This was obviously not pressure related as it was far below the rated pressure of the machine, so I figured it might be a current limit. With the three-phase motor, the current had been divided between three phases and therefore three current-limiting breakers in the pressure switch. But with a single phase motor, all of the current would be flowing through one breaker, overloading it. There's a little dial on the top of the breaker which is marked 4, 5 and 6.3, so I surmised these must be current cutouts. So I moved the dial from 4 to 6.3 and tested again, and lo and behold, the compressor still cut out, but this time at 7 bar. I figured I needed more current capacity than this switch could cope with, so I'd need to replace my pressure switch with one designed for a single phase motor.
The breaker is made by a company called Condor, which turns out is a German company. And their website lists a company called Alpha Controls as their UK distributor. So I called up Alpha Controls and spoke to Christine there, who told me that for various reasons (I imagine Brexit and COVID-related driver shortages don't help) they had not had any deliveries from Condor for weeks so had lots of pressure switches on backorder. But she did have various modular pressure switch breakers in stock, which she told me is called the relay and I could replace the relay in my pressure switch. We settled on the next one up, which ranges between 6.3A and 10A. Given that I'm running this thing off a standard 230V 13A mains socket, I couldn't go much higher anyway! £23 and a day later, and my new relay arrived by special delivery. I found that it only took two screws to loosen to remove the lower capacity relay and replace it with the higher capacity one. Knowing that 6.3A was too low, I set the dial on the new relay to half way between 6.3 and 10A and then I tested again. Success! This time, the compressor run until it reached 10.5 bar before the pressure switch shut off power to the motor - but this time, rather than tripping out on an over-current condition and returning the switch to "off", the switch stayed in the "Auto" position. Which I hoped would mean it would restart again when the pressure in the receiver fell. I used my blow-gun to vent pressure. It took a few minutes with my blow gun on full blast to drop the pressure from 10.5 bar to 8 bar, after which the motor started up again and quickly brought the air pressure back to 10.5 bar. Sorted!
Clarke had warned me that I needed to use a 30A mains supply with the single phase motor, but I find it works fine from the 13A sockets in the garage, even when it's restarting at 8 bar.
To-do jobs: I really should fit those anti-vibration feet. The compressor doesn't make as much noise as I thought it would (certainly less than my little 25l Wolf Air compressor) and it doesn't seem to vibrate at all. But I've bought the feet so I may as well use them. There are two small nuts, two washers, and a third larger nut. I haven't yet figured out how to arrange them on the receiver's feet. Any suggestions much appreciated.
I also need a vent valve for that lower outlet. I could continue to use it to power my tools, but I don't want excess water and oil in my lines. Yes, I know I should be using lubrication with some tools, but I think this oil comes from the compressor and isn't the same oil that air tools use. And most importantly, I need to source a regulator and filter and figure out how to plumb it onto that large receiver outlet. Ideally I want to use a 2M length of hose and mount the regulator and filter on the garage wall; however, finding short lengths of air hose is easier said than done. I want to use as large diameter hose as I can, as I eventually want to get a sandblasting set-up and that needs lots of CFMs. And now I have a 15CFM compressor, it would be a shame to hobble it with small diameter hoses. My existing tools work fine with narrow lines, but for a fixed line on the wall I want to keep it as free-flowing as I can. This PCL one with built-in lubricator might do:
https://www.screwfix.com/p/pcl-atcfrl12-bsp-air-to...
or perhaps I'll just use an in-line oiler when using tools which need oil:
https://www.screwfix.com/p/air-tool-mini-in-line-o...
Thanks for your time and suggestions!
After weighing up all the options including building a rotary phase converter and buying a variable frequency drive 3-phase inverter, I decided that I wanted the compressor to be able to start and stop by itself as the air pressure in the receiver rises and falls and I didn't want the wastage of a rotary phase converter that I would have to start and stop. I decided that I'd get on to Clarke and enquire what motor they use in the single-phase version of the current VE15C150 comes in both single-phase and 3-phase variants. Once the motor was identified, I decided to buy it from them (£180) along with a 3/4" ball valve (£14) for the receiver outlet and three rubber anti-vibration feet. I thought I'd put the ball valve in the reducer ring which brings the 1" outlet down to 3/4". But it turns out that BSP threads are weird, and for some reason unfathomable reason, a 1" thread is actually called 3/4" BSP thread and you have to keep subtracting 1/4" to get the name of the product you want. No idea what's going on there. What this meant is that I had to remove the reducer ring from the receiver and fit the 3/4" ball valve directly to the receiver outlet. And then I put the reducer ring onto the outlet of the ball valve. So now the outlet after thee valve measures 3/4", which means it'll take 1/2" hose fittings.
With the compressor now fitted with a ball valve, it was now time to remove the three-phase motor, but first I had to remove the cage that protects the pulleys. Or rather, the cage that protects you and me from the pulleys! After undoing the four bolts that mount the motor foot to the top plate and removing the motor power cable from the pressure switch, I was able to take the motor off and plonk it on my workbench - the building of which was a project I began in early lockdown last year.
The new motor came without a pulley, but it needed the same size pulley as the original, so I thought I'd undo the grub screw holding the pulley onto the output shaft and slip it off. Or so I thought. Nothing I could do would let me get that pulley wheel off the shaft. I tried levering it off with a crowbar, I tried making wooden wedges to get it off. Nothing worked. In the end, I ordered a 3-leg puller, and with the help of my impact driver, was able to remove the pulley wheel without any trouble. I guess the old adage of having the right tool for the job still holds.
I was then able to install the pulley onto the new motor, although it required a few gentle whacks with a rubber mallet and a large socket to get it to slide into place on the shaft.
I then shoved the contacts from the motor straight into a mains socket, and flipped the switch. Would the motor run in the correct direction? Would it blow my circuit breaker with too much inrush current? Nope, the motor burst into life, but there was a problem. There was a weird pulsing vibration from the drive belt, so I flipped the switch off quickly to investigate. It turned out that despite thinking I'd tensioned the belt sufficiently, it wasn't tight enough. Worse still, the motor had moved slightly in its mounting bolt slots, and the drive pulley wasn't properly aligned with the compressor pump pulley. Off came the front of the guard, and out came the puller. A few seconds later everything was lined up properly. I also used a piece of wood wedged between the motor and pump to get the tension right. Once I was sure everything was lined up and taut, I re-tightened the motor mounting bolts.
I then flipped the mains switch and let the compressor start to build pressure. The pressure gauge rose fairly quickly to 2 bar, 3 bar, 4 bar when suddenly there was a sound like an explosion and there was liquid pissing out of the bottom or the receiver onto my garage floor. I knew that there was a drain fitting at the bottom of the compressor, but I hadn't physically checked it. I figured that I'd hear air escaping if it was open, and that if the pressure rose, it must be sealed. But it seems it was open, but blocked by something. In fact, it's just another outlet positioned at the bottom of the compressor to drain condensation. I don't know how it was rigged in situ, because I doubt anyone at the Sainsbury's petrol station physically crawled on hands and knees to vent it periodically. I'm guessing there must have been a hose fitted which led to some remote vent valve on the outside of the tyre machine pumping machine. And I doubt it was used judging by the amount of oil that found itself lubricating my garage floor.
The vent pipe is much smaller than the main outlet, but a 10m length of the air hose with threaded ends that I rescued at the same time fitted perfectly, and I put a female XF connector at the other end of the hose and connected it to my blow-gun. That took care of all of the open outlets, and again it was time to see if the compressor would get up to its operating pressure of 10 bar. But before I wanted to risk that, I wanted to wire up the motor to the pressure switch. That way I'd have a better way of switching off than at the wall, and I'd also have the safety of the system shutting itself off when it got up to pressure.
Once wired up through the pressure switch, I discovered that it kept tripping out and flipping its own switch to the "off" position when the compressor got to about 3 bar. This was obviously not pressure related as it was far below the rated pressure of the machine, so I figured it might be a current limit. With the three-phase motor, the current had been divided between three phases and therefore three current-limiting breakers in the pressure switch. But with a single phase motor, all of the current would be flowing through one breaker, overloading it. There's a little dial on the top of the breaker which is marked 4, 5 and 6.3, so I surmised these must be current cutouts. So I moved the dial from 4 to 6.3 and tested again, and lo and behold, the compressor still cut out, but this time at 7 bar. I figured I needed more current capacity than this switch could cope with, so I'd need to replace my pressure switch with one designed for a single phase motor.
The breaker is made by a company called Condor, which turns out is a German company. And their website lists a company called Alpha Controls as their UK distributor. So I called up Alpha Controls and spoke to Christine there, who told me that for various reasons (I imagine Brexit and COVID-related driver shortages don't help) they had not had any deliveries from Condor for weeks so had lots of pressure switches on backorder. But she did have various modular pressure switch breakers in stock, which she told me is called the relay and I could replace the relay in my pressure switch. We settled on the next one up, which ranges between 6.3A and 10A. Given that I'm running this thing off a standard 230V 13A mains socket, I couldn't go much higher anyway! £23 and a day later, and my new relay arrived by special delivery. I found that it only took two screws to loosen to remove the lower capacity relay and replace it with the higher capacity one. Knowing that 6.3A was too low, I set the dial on the new relay to half way between 6.3 and 10A and then I tested again. Success! This time, the compressor run until it reached 10.5 bar before the pressure switch shut off power to the motor - but this time, rather than tripping out on an over-current condition and returning the switch to "off", the switch stayed in the "Auto" position. Which I hoped would mean it would restart again when the pressure in the receiver fell. I used my blow-gun to vent pressure. It took a few minutes with my blow gun on full blast to drop the pressure from 10.5 bar to 8 bar, after which the motor started up again and quickly brought the air pressure back to 10.5 bar. Sorted!
Clarke had warned me that I needed to use a 30A mains supply with the single phase motor, but I find it works fine from the 13A sockets in the garage, even when it's restarting at 8 bar.
To-do jobs: I really should fit those anti-vibration feet. The compressor doesn't make as much noise as I thought it would (certainly less than my little 25l Wolf Air compressor) and it doesn't seem to vibrate at all. But I've bought the feet so I may as well use them. There are two small nuts, two washers, and a third larger nut. I haven't yet figured out how to arrange them on the receiver's feet. Any suggestions much appreciated.
I also need a vent valve for that lower outlet. I could continue to use it to power my tools, but I don't want excess water and oil in my lines. Yes, I know I should be using lubrication with some tools, but I think this oil comes from the compressor and isn't the same oil that air tools use. And most importantly, I need to source a regulator and filter and figure out how to plumb it onto that large receiver outlet. Ideally I want to use a 2M length of hose and mount the regulator and filter on the garage wall; however, finding short lengths of air hose is easier said than done. I want to use as large diameter hose as I can, as I eventually want to get a sandblasting set-up and that needs lots of CFMs. And now I have a 15CFM compressor, it would be a shame to hobble it with small diameter hoses. My existing tools work fine with narrow lines, but for a fixed line on the wall I want to keep it as free-flowing as I can. This PCL one with built-in lubricator might do:
https://www.screwfix.com/p/pcl-atcfrl12-bsp-air-to...
or perhaps I'll just use an in-line oiler when using tools which need oil:
https://www.screwfix.com/p/air-tool-mini-in-line-o...
Thanks for your time and suggestions!
GreenV8S said:
Good job!
I'd say you have arranged the nuts and washers correctly. The large nut goes under the flange and the washer and smaller nut clamp it from above.
Media blasting with an oily air supply may not be a happy experience, but I guess you'll find out soon enough.
Funny you say that - I've just been on to PCL to enquire whether the lubrication of the ATCFRL12 can be shut off, and the answer is no. I can run it dry but not turn it on and off. So instead I'm going to go for a regular filter and regulator and to the lubrication downstream only if necessary. I have no reason to believe that the air from the receiver outlet half way up will be oily - I think the oil is just what's collected in the bottom of the receiver after 10 years of operation.I'd say you have arranged the nuts and washers correctly. The large nut goes under the flange and the washer and smaller nut clamp it from above.
Media blasting with an oily air supply may not be a happy experience, but I guess you'll find out soon enough.
hidetheelephants said:
It would have been fitted with an automatic moisture drain, which given the clog of sludge in the pipe would appear to have done what auto drains do when not maintained, which is stop draining.
Thanks - I didn't know these existed, but now I do. I might buy a cheap electronic timer valve, or perhaps I'll just fit a 30cm length of air hose and a release valve at floor level within easy reach.LunarOne said:
Thanks - I didn't know these existed, but now I do. I might buy a cheap electronic timer valve, or perhaps I'll just fit a 30cm length of air hose and a release valve at floor level within easy reach.
Auto drain traps are used on all large systems. Modern ones are electronic but old ones just use a float valve.I would just fit a tap and remember to blow it down every time but there are timed units that seem cheap
https://www.ebay.co.uk/itm/363331522539?chn=ps&...
Or a mechanical one https://www.ebay.co.uk/itm/234088795618?chn=ps&...
Of course, the moisture causes rust inside the receiver so its worth draining it down at the end of every use but they always tend to remain a bit soggy. Our systems have big dryers before the receivers, but they still end up a bit wet.
Spent a few fun evenings draining gallons and gallons of water out of instrument air systems when the dryers have failed.
Edited by Gary C on Friday 27th August 17:46
I manage a compressed air company, there are a few things I'd point out from your post;
1) if that receiver drain was blocked there may well be internal corrosion, I'd want to look inside and check it. (a commercial user has to inspect it every 24 months and insure it against failure if it is over 250 bar litres ie more than 25 litres at 10 bar)
2) for a machine that size we never bother fitting any sort of auto drain, simply put a large ball valve on there and manually drain it regularly. The rust and sediment in that will block most drains very quickly.
3) That receiver should have a safety relief valve on it. For your safety I would replace it with a new 11 bar one.
4) Surprised to see the pressure control is determined by current draw, normally there is a mechanical pressure switch that breaks the circuit at the pressure you set.
5) Keep a close eye on the pully alignment and belt tension, if either go out you will eat belts.
6) This thing will muller your electric bill.
1) if that receiver drain was blocked there may well be internal corrosion, I'd want to look inside and check it. (a commercial user has to inspect it every 24 months and insure it against failure if it is over 250 bar litres ie more than 25 litres at 10 bar)
2) for a machine that size we never bother fitting any sort of auto drain, simply put a large ball valve on there and manually drain it regularly. The rust and sediment in that will block most drains very quickly.
3) That receiver should have a safety relief valve on it. For your safety I would replace it with a new 11 bar one.
4) Surprised to see the pressure control is determined by current draw, normally there is a mechanical pressure switch that breaks the circuit at the pressure you set.
5) Keep a close eye on the pully alignment and belt tension, if either go out you will eat belts.
6) This thing will muller your electric bill.
LunarOne said:
OP did you ever get anywhere with this? This evening at my local Sainsbury's petrol station I saw a Clarke Industrial air compressor standing in a Hippo bag, clearly awaiting collection. I checked at the petrol station to see if there was any chance I could have it, and they said they couldn't see why not but to ask the manager in the main store. So I went and asked and they said I was welcome to it. So I came home and got my A4 Avant which it turns out is only just big enough for the compressor. Apparently it works fine, but was removed when they renewed the air machine and the car wash a couple of weeks ago. I haven't been able to test it as it's got a 3-phase motor and I don't have a 3-phase supply, but I did hear of ways to convert the motor to use a single phase supply, or to change the motor for a single phase one. I'm not sure of the exact specs as it was dark, but here are some photos of the unit, now standing in my garage. My current compressor is a 25l Wolf Air and when using it with air tools the compressor fires up after just a few seconds and I've been hankering after a bigger vertical compressor for ages. From what I can see online, it's 14CFM and has a 150 litre receiver. A great freebie if I can get it going and maybe worth something to someone even if I can't!
Amazing find! Even if you just stick it on eBay that's a huge win. 
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