Yes, Dean. You missed numerous episodes of StarTrek/DS9.
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Yes, Dean. You missed numerous episodes of StarTrek/DS9.
I used to be a Treky! I watched DS9 too... not the same as Star Trek though... :)
My kinda guy...these days it's "BattleBots" and "Junkyard Wars"
No slamming of Junkyard Wars!! LOL!! You never know... one of the episodes may show a primative Warp Drive system...
:D LOL!!!
The Prof has a bad habit of making obscure remarks :(, though he senses a number of science fiction fans in this group. <b>ODO</b> would make an interesting name for a valve, say one that could change its capacity, if Paramount Pictures not claim royalties to it..
I posted something earlier in this thread that wasn't correct and Gary caught it. I knew what I was thinking but for some reason I went off the deep end with the wrong explanation.
If the TXV's are not closely balanced, in a parallel system they will fight for control. Of course the one with the lowest s.h. will ultimately control both circuits. That is why solenoid valves are needed. Now I think I have stated it correctly this time. Thanks Gary.
:)
well ill just dive in! Ive read all of the threads on this subject. It seems to me that the run times for this box are going to be long. most times a pressure controllers off cycle will be to short to control ice. I would think this would be true in your case(90-95 degree surrounding box temp). Id be against adding LL solenoid valve due to the increased load it will put on the compressor with one closed. We will possibly have some major liquid slugging.
Anyway, if all else fails get a bigger hammer:)
Hey thats no joke... I have seen locked up compressors that just needed alittle LOVE TAP to get them going again! LOL!!
;)
Subzero, with due respect, I beleived Bernie is right. solenoid maybe good for adjusting SH. but present a bigger problem down the line.
My way of thinking, even if the TXV is not exactly adj - but reasonablly close to each other, one evaporator will carry a slighly bigger load. I can not see how one TXV can eventually over power the other. Unless the other one is none functional.
Bear in mind, both evaporator is cooling the same space, same temperture.
hey dan consider this. Its not uncommon for folks to use one side of the box frequently i.e. opening and closing the door all day long. If it were me id probably due that design change thing and jam a remote bulb thermostat in the evaporator that always freezes and set to cycle off at say 18 degrees and back on again at 41. this should cure the ice problem somewhat. good luck
Bernie, your are right about one side openning more than the other. As I've mentioned earlier, unit is working good now. I don't planned to do any adjustments.
The other contractor installed a defrost timmer- the ones use in household refrigerators- it appeared to solve their problem also.
The intend of my original post was to find out how expert adjust super heat with multi-evaporator set up. not how to jury rig the system. Most of the time I know how to jury rig and get around the problem. However, as a professional in this field, I preferr not to jury rig. Frankly, it bothers me whenever I see other people jury rigged around a problem - instead of fixing the problem like it is supposed to be fixed.
ok dan, i also agree that we are all professionals striving to do the right and proper repairs for all our accounts. I think the important thing to remember is this. Sporlan takes great time to factory adjust all tev that leave the factory. There is one that will fit every application i can think of. now lets consider this, every piece of equipment we work on has a specific reqirements and controls in order to function properly. prime example is surrounding ambient and load usage. im of the belief that if the valve is not controlling the proper superheat its either bad or something else is causing the problem. if the charge and all controls check out, it is our responsibility to provide our customers with solutions. If its 95 degrees, and the doors are always opening, odds are the box will never satisfy. so we can either tell the customer to condition the air around the box, chuck it in the garbage, or we can jam a remote bulb t-stat in the evaporator and set it for say 18 degrees off and back on at 41. I appreciate your wanting to do the right thing.
Sometimes when a system is new and still under warranty, and after all standard proceedures are followed will authorize Bernies suggestion. In fact if the situation is known to exist with a given restaurant chain, they may even write a service bulletin. Good idea for an immediate fix in that particular situation Bernie.
thanks sub, i was begining to feel all alone out here.
I think there are a number of options open to us all. As long as we can consistently achive the results were after,
and the unit works properly, it cant hurt.
Im new to this site and i have to say im hooked.
Okay, I confess. I have put a time delay in parallel with the normally closed contacts on lockout relays on a few occasions...lol
Thanks for coming out of the closet gary, i know this is hard.
LOL. It is tough duty for Gary to admit to changing design. For good purpose too. I once ran a check on the stores that are easy for us to provide service on, versus the ones that are farther away. Anybody care to guess what the survey results were? It is flat out embarrassing.Quote:
Originally posted by bernie
Thanks for coming out of the closet gary, i know this is hard.
Ugly. The stores we service the least are the stores that work the best. Gary, do you want to start a new thread along these lines? You could call it "Don't adjust anything!"
Dan
Or maybe "Don't Touch That Dial"...lol
Hey... I have no qualms about redesigning a system... just fess up if it messes up.... LOL!!!
I love taking older systems and retrofitting them or bringing them up to speed so to speak. In fact, if I can... I will revamp an older unit rather than a newer unit... just so I can listen to the owners say how good that old one runs compared to the new ones! LOL!! Plus if it was already messed up you can't really go wrong... sometimes you might have to make a service recall to tweak it but what the heck... those oldies are worth it.
I do have to admit that I get carried away sometimes when I am rebuilding though... I can't help it.... is there group therapy for refrigeration engineers?! Imagine the typical refrigeration engineer... he/she must look like a cross between Bob Villa, Tim Allen and somebody from Junkyard Wars... LOL!!!
subzero, I too like to redesign system. I think many system can be improvered by customized to a particular situation. As a minority contractor, I run into many minority business owners where they purchase most of their equipment from; auctions, junk yard, recyle depot, etc... ninty percent of equipment are mis-matched. For someone who is very knowledgeable, that is good, for many who think they know but doesn't, that is bad. There is a big different between REDESIGN and JURY RIG around a problem. I've done my share of designing and redesigning system, probably more than many on this forum.
A wise tech or engineer should recognize limitation of their abilities. They should also recognized wheather a particular situation calls for a "proper repair" or "redesigning" or if its a "jury rig". I have run across many situation that are "jury rigged" or "extreamely poor designing" by some ranking amature or handiman that makes me puke. I am appenhensive to "jury rigging" without doing a throught reseach. One of the many reasons for my original post in this form.
I must admit Dean, there is no better feeling then to take a old piece of equipment and resurrecting it. Making it work better then it ever did, control better and just hum. Gives me Goose bumps!! LOL
Dear Mr. Wong
Ive just completed reviewing all these posts, yours inparticularly.
You stated that it makes you mad when you see amatuers
"jury rig systems", yet on this thread you have done just that.
You have changed the expansion valves, and you have also installed
a different type of thermostat to control ice. Both of these repairs
are not necessarily wrong, but they due fit the very definition of design change. A customer will stop at nothing to ensure he does not lose all the product he just wrote a check for. A good
service tech should do the same to protect it. Call it what you
like, but as your posts prove design change is sometimes necessary, due to the fact our customers are always pushing the
limits of the equipment we maintain. This has been are good thread to kick around. I'm having fun;)
Bernie, I am afraid you caugh me on that. I think there maybe a slight mis-interpretation of what I mean. let me rephase my remark hopfully this will help clearify what I mean to say.
first, I am not against design and redesigning a system if it is a benefit to the customer. sometimes that is the only option avaible. as I've mentioned on my previous post many of my minority customer purchased their equipments from auctions, scrap yards etc..mis-match pieces, the only option is to design and redesign. I've done plenty and enjoyed very much doing it.
second, when it come to repair, I like to see a piece of equipment repair as close to its design condition as possible w/o modification.
third, If modification are necessary sometime they are. the tech should throughly understand why they are doing it, what happen after they done it. further they should investigate better way. God bless the creator of this forum, now I can refine my skill further.
fourth, I am against "jury rig" type modification. several examples;(1) thermo overload disc bad, instead of replacing the dame thing, they jumper it. (2) hi pressure switch activate a lot due to over pressure condition, it became a neucens for the customer and the tech, so they bypass it. (3) fusible plug blown and leaks, they removed it and put in a regular solid brass plug. (4) bad fan motor, they replace a motor physically fit but wrong rpm, and wrong amp rating. 5) ice machine with water cool condenser, instead of replacing the bad water pressure regulator, they install a solenoid valve when compressor run - valve open. too many to list......
thank for putting up with mee, I will see what I can do to polish up my english. lol:cool:
I've notice star war, junkyard war being mention here. Ever wonder what kind of advance refrigeration system they use?????