Compressor knowledge needed

[Leadfoot21]

I used to work for a mom and pop compressor shop, we worked on everything under the sun and were the shop to call when the OEM dealer didn't want to deal with old junk so I got a chance to work on just about every brand out there. We sold Palatek rotary screw machines and joked they were built out of a grainger catalog, which is a good thing, there were very few proprietary parts on them and parts were easy to get. They were built to last and hard to kill with minimal maintenance. They used all analog controls and didn't have a PLC or controller like most manufacturers have gone with. The only thing digital controls do is make it easier to adjust load/ unload pressures at the controller instead of adjusting a pressure switch and pilot valve with a screw driver to get the desired settings. They really aren't needed and can give you a huge bill when they die and require an updated retrofit. We had a lot of Palatek 20-30hp rotary screw machines with over 100k hours on them with oil and filters every 3-6 months and a separator every 1-2 years and very few repairs over the life of the machine. I now take care of a 12 atlas copco rotary screws from 5-250hp and wouldn't buy one unless you want the dealer to work on it and to get bent over for proprietary parts. I didn't work on a ton of Quincy machines though don't remember any major problems with them. Newer sulair machines with digital controllers required a sulair tech to reset the maintenance light. If you have a Sullivan Palatek dealer in town I'd ask for a quote.

I have 0 experience with the brand your compressor shop is trying to sell you. A quick look at their website shows digital controllers which might be fine or might be an issue and parts availability in 5 years could be an issue.

Buying a rotary screw compressor in a factory cabinet usually quiets it down a ton along with venting the cooler discharge outside. If your shop has a bunch of dust or oil mist a built in furnace filter on the cabinet inlet really kept coolers a lot cleaner.

How are the current compressors setup? Do they all run at once or do you have a lead, lag, and lag lag that kick on based on demand? Determining how often how many of the current compressors are running will give you a better idea on your true air demands. We used the rough math of 4cfm per HP of rotary screw machine.

Many shops are running 100-125psi rotary screw machines and don't notice the change from a 175psi piston machine. Automotive repair as a whole is going away from air powered tools compared to 10 years ago. You may not need as much air compressor as you currently haven unless your shop is still using a ton of air tools. It's been 5 years since the compressor gig so my memory is a little foggy on who was running what sized compressors though 30hp seems like a lot for a 12 bay shop unless all 12 bays are doing tires all the time or you have a body shop. I want to say most dealerships that size were in the 15-20hp range with rotary screw machine and they were over sized for the most part. Big O tire shops mainly ran 7.5 to 10hp rotary screw compressors and as long as their air leaks were kept in check they had no issues keeping up. Did qunicy study your current air usage or just go your current compressors put out 102 cfm, a 30 should do?

I agree with using your current compressors tanks will save you some money. I'd run the new machine as your main and have the best of the current piston machines setup as a lag machine that kicks on when demand is high or the lead has issues. Something like a lead setup to load at 105 unload at 125psi and a lag set to load at 95 and unload at 110psi.

Thank you for the response . We currently have 3 10hp compressors putting out a combined 100-110 cfm I’m assuming they’re set up on demand . Only 2 work right now so a max of say 60-70 cfm and they’re getting so overworked they’re throwing shotgun fuses . Tools are provided for all our techs so we are making the transition to cordless impacts but they’re on our service trucks primarily at the moment which has been a huge improvement . We do also have a body shop and we do an absolute crap load of tires and tire repairs daily . They definitely didn’t do an air usage study and I also wonder if we couldn’t get away with a 15-20hp also .

 

[barrelroll]

Thank you for the response . We currently have 3 10hp compressors putting out a combined 100-110 cfm I’m assuming they’re set up on demand . Only 2 work right now so a max of say 60-70 cfm and they’re getting so overworked they’re throwing shotgun fuses . Tools are provided for all our techs so we are making the transition to cordless impacts but they’re on our service trucks primarily at the moment which has been a huge improvement . We do also have a body shop and we do an absolute crap load of tires and tire repairs daily . They definitely didn’t do an air usage study and I also wonder if we couldn’t get away with a 15-20hp also .

If you are blowing fuses frequently there might be an issue somewhere that's not necessarily the compressors themselves. We had plenty of piston machines in closets at discount tire stores that would run non stop in 100 degree temp without issues.

When your compressors are on are they always both running or does one run for longer than the other? Do they ever shut down on their own once you fire them up in the morning or run non stop till it's time to go home? Also throwing an air fitting on a 0-200 psi gauge in a coupler near your bay and watching pressures throughout the day will give you an idea of what things are doing.

With a body shop depending on how many people are in the body shop you may be in 30hp territory. If 2 machines are barely keeping up putting out 70 CFM you probably want to go bigger than a 75 CFM 15hp rotary screw machine. Ideally you want the machine to be big enough to cycle and get a bit of a break throughout the day.

How bad are the air leaks in the shop? Getting a handle on the air leaks can sometimes be enough to go from under sized compressor to right sized. I got called to a tire shop because their compressor wasn't keeping up, they are thinking it had to be a compressor issue. Isolate the valve on the receiver, the compressor makes air, reaches unload pressure and unloads just as it should. I start walking around the shop to find the air leak, there's a rag wrapped around the air line to the tire machine, hmmmm. The line to the tire machine was broken 3/4 of the way around basically dumping most of their air to atmosphere. Fixed the leak and now the compressor loads and unloads like it should instead of running loaded all day long. I'm guessing they saw the change on their power bill and their compressor was much happier. Many times shop owners wouldn't want spend the money to fix leaks or buy couplers when the leaks were actually costing them money in power and wearing out the compressor much quicker.

Getting someone out there who will look at the whole picture might be worthwhile. The Quincy shop knows you guys are willing to drop the coin on a new compressor so you got the sales pitch instead of a good look at the whole system. We ended up with a lot of good used machines thanks to other compressor companies convincing customers they needed new compressors.

or spending the time to wrap your head around what's going on before throwing $10k at the problem

 

[Leadfoot21]

barrelroll air leaks are almost nonexistent we stay on top of that kind of thing . They don’t run all day they kick off and on as needed . The electric motors on both compressors are going bad . Supposedly they’re nothing spiking out huge amperage draws when they’re restarting hot and blowing the fuses. Boss said he didn’t want to keep throwing money at them being 31 years old and we have been getting a lot of noise complaints from people in the office about how they have gotten so loud . They sound considerably louder than they used to and when I went to inspect them the other day it appears they’re getting so hot from usage that the powder coat or paint has bubbled in spots . I’m in my office right now and they’re running and it is obnoxiously loud from quite some ways away through an entire story and many walls.

 

[arse_sidewards]

barrelroll air leaks are almost nonexistent we stay on top of that kind of thing . They don’t run all day they kick off and on as needed . The electric motors on both compressors are going bad . Supposedly they’re nothing spiking out huge amperage draws when they’re restarting hot and blowing the fuses. Boss said he didn’t want to keep throwing money at them being 31 years old and we have been getting a lot of noise complaints from people in the office about how they have gotten so loud . They sound considerably louder than they used to and when I went to inspect them the other day it appears they’re getting so hot from usage that the powder coat or paint has bubbled in spots . I’m in my office right now and they’re running and it is obnoxiously loud from quite some ways away through an entire story and many walls.

So what you're saying is you're about to have two used motors for sale with enough life left in them for home shop use?

 

[barrelroll]

barrelroll air leaks are almost nonexistent we stay on top of that kind of thing . They don’t run all day they kick off and on as needed . The electric motors on both compressors are going bad . Supposedly they’re nothing spiking out huge amperage draws when they’re restarting hot and blowing the fuses. Boss said he didn’t want to keep throwing money at them being 31 years old and we have been getting a lot of noise complaints from people in the office about how they have gotten so loud . They sound considerably louder than they used to and when I went to inspect them the other day it appears they’re getting so hot from usage that the powder coat or paint has bubbled in spots . I’m in my office right now and they’re running and it is obnoxiously loud from quite some ways away through an entire story and many walls.

Sounds like you have the air leaks covered. Being 31 years old it does sound like they got their money's worth out of them. Good luck with your search for a compressor available in a reasonable amount of time. The place I used to work at in Denver would keep refurbished and good used compressors in stock and would probably ship if you got into a bind. They would also put in a rental machine for a couple weeks with a logger to get an idea on sizing before pulling the trigger on a new machine if sizing was a concern which might be worth looking into if you are thinking about a smaller machine.

Are they planning on keeping one or two of the old machines as lag/ backup compressors?

 

[Leadfoot21]

Planning to keep the two running machines in their original locations and remove the one that isn’t functioning and relocate it for storage only . The ones in use now will be back up or for emergency usage . I submitted the purchase order today for approval . We will see what happens! If nothing else this will serve as a review for Kaishan !