Supermarket various leaks
Hello, I started for a new company this year and they don't do a lot of supermarket work but they do the largest supermarket in the city. The racks are quite old here and I find small leaks sometimes during repairs by finding oil and then I fix the leak. I spend the most time at this place at the moment and I want to start getting these leaks found and fixed but I dont have enough time to do the work thats currently needed never mind leak searching. I want to know what tools and techniques you supermarket guys use to find leaks and lets just say money is not a issue for purchasing of tools. Your help is greatly appreciated, Thanks
Flash light, electronic leak detector, ultrasonic leak detector, soap bubbles, mirror, and patience. Most leaks ain't to hard to find but some will require you to pull your truck on the roof and use every tool you have. A good vacume pump and micron gauge are a must as well. I start with mechanical connections and service valves, 90% of your leaks will be found there. Then onto the coils starting with tube sheet. Then onto the accumulators and receivers, the accumulators mounted upright will rust out on bottom and hide from you. Last is the lineset and brazed connections. Not every leak will show oil so don't assume if there's no oil there's no leak.
You say that the racks are "quite old" Let's be more specific... Are they 10 years old? 20? 40?
Start with this. CLEAN THEM. Take a nice bucket of soapy water and a good degreaser and clean them up and keep 'em clean. It'll help with spotting the slow, oily weeper leaks.
Now, fire up a GOOD electronic leak detector. I could go on a rant about which ones that I like and what I think of those that I don't, but we're looking for leaks, now, so get the one that you've got. I'll stick with my H-10PM. Walk the cases. Make a note of where you pick up leaks. You've got a lot of ground to cover, so don't try to stop and fix them all, just find 'em and note them and note from the detector's behavior if it was a big leak, a medium sized leak or a little leak.
Now, you've got a list to work from. Sit down and organize it and create a plan of attack. Start with the largest leaks and work down from there. Be patient, you aren't going to fix them all after lunch on a Friday.
Repeat this process with the mechanical room, the condensers and any auxiliary coils like heat reclaim.
Now, start over. Sometimes, larger leaks tend to mask smaller leaks and it takes time to let the excess refrigerant dissipate.
Now, you've got a tight store with nice, clean racks. KEEP IT THAT WAY.
Do monthly leak checks, clean up the oil that you spill or that results from leaks.
I want to take a minute to specifically address this statement.
Originally Posted by goodguyu
If you don't stop and take the time, MAKE the time to do what is needed and do it correctly the FIRST time, then you will NEVER have the time to do it correctly.
Putting a half-a**ed repair on a piece of equipment just to run to another call to slap a band-aid on it to get to the next call....
Then, what happens is the half-a**ed, band-aided repairs start to unravel and you wind up starting to run call-backs intermixed with normal break downs.
Now, you've got even LESS time to do what needs done.
So, what do you do? Make quicker repairs. Use lighter bandaids. Add MORE gas to buy yourself more time until they call back again when it leaked out.
STOP THE MADNESS!
Ok, I'm going to step off of my soap box, now and maybe have a beer. I think I need one....
Installing a systematic leak detection system will help and i guarantee you it will pay for its self. But like jp says you gotta fix the leaks.
If the store is r22 and has a high concentration that a halide torch can help you pinpoint leaks too.
We do more grocery store work than anyone and what jp said is spot on. For us by the time you make it to the machine room, and set down your tools, the office is on the phone asking when you're going to be done. Those that throw bandaids on things get the most praise. The problem re-occures in a couple months and all is forgotten by the sloppy office. Never fails hot weather hits and we're bogged down with heat related issues and then all the call backs come back to bite you in the a**. Some hot days we have 40+ calls come in between a few service guys. Now you start putting bandaids on things because you want to get home one day. It's a team effort though and if half the guys won't cooperate and no one in the office has any experience or knowledge then you do the best you can. I run so many call backs from some guys it's embarrasing.
Originally Posted by jpsmith1cm
I'm somewhat skeptical of these systems.
Originally Posted by steve wright
They're a great HELP in catching leaks early, but nothing but NOTHING is better than a skillful and determined technician on the ground with a good electronic detector.
The original store racks are about 35 years old from what i'm told and are 134a and 507. The other additional racks are about 20 years old and are also 507 134a. The problem with this place is the band aid repairs are everywhere and work like this has been done like this for years due to the lack of time or know how. I'm definetly not doing bandage repairs myself, I'm trying to figure out the best plan of attack to get things gradually sorted out and in shape. I'm sorting out a time frame for a week of leak finding and repairs but I want to make sure I'am productive with my time since I've never went leak hunting in a supermarket before. When you say "walk the cases" do you simply mean putting the leak detector into the bunker air stream to see if it picks up on anything. The degreasing of the racks and clean up I can have done easily by sending a apprentice. Thanks for the help
Walk the cases. Yep, just what you think. Put the detector in every case and see what happens.
A week might be OK, but I wouldn't let myself get tied down to it.
Tools I use for leak checking:
Turn on your leak detector and let it calibrate outside in fresh air.
Walk into the store.
If you get immediate leak detections as you walk in, shut off the air handlers, make up airs, & exhaust fans...stop air movement in the store.
Leak check the sales floor cases by sticking the detector in the discharge air stream of the cases.
If you have underground line penetrations, leak check the stub ups.
If you have overhead lines, keep and eye out for stained ceiling tiles, it could possibly be oil.
Leak check the walk-in boxes, inside of them and on top of them.
Leak check the motor room.
Shut down the racks while leak checking the motor room, and anything that moves air in there, like exhaust fans.
leak check where the lines penetrate the motor room.
Over head lines, stick the detector through the wall.
Underground lines, stick the detector down the penetration.
If you have overhead lines, usually there is some kind of "cat walk" that will allow you to walk around in the ceiling. If so, leak check up there.
If the over head lines are inaccessible without a lift. Then you will need to leave them alone until you can prove there is a leak & its nowhere else.
Then you need a lift, or pressurize inaccessible lines with nitrogen...but again, only if there is a proven leak & it's not detected anywhere else.
Leak check the condenser, again, with the racks off so you can shut the fans off to stop air movement.
Leak check air handlers cooling coils, reheat coils with the blower motors off.
Then once you start finding leaks, depending on where they are. There are tricks to pinpoint, isolate, repair them. But as you find them, we can all address them at that time.
Hussmann smg service case coils leak a lot. We replace them all the time. Also don't be alarmed if your leak detector goes off in a hot water heat reclaim tank. The insulation will make it go off. Do a standing pressure test if you think it's leaking. I use the exact setup phase loss does. The tif zx is the most sensitive leak detector on the market. I also use the H-10 with it.
Thanks for all the excellent help guys Ill be sure to use some of these strategy's.