MemberNovember 12, 2020 at 12:10 pm
HI- lucky me- I get to work on another ice machine. I go and find that there is no ice, an alert on the display and when I look at the errors- I find- T4 fault. Possible causes- cleaning, install, starving TXV, and ice probe thickness. Well its not ice probe- its not making ice. Its not install its been there 4 years. So I cleaned it- and it was nasty. At first when I saw the TXV I thought i had a leak- but its not- and I have no idea what the issue is with the staining and what appears to be a wet spot on the foam. There is no oil nor is it “wet”. Second- you can see the thermistor temps- I was going to change t3 and 4 because nothing in there is 300-400 degrees it says t3 is 275 and t4 is 395 degrees— when I touch them they are not hot- so they are not reading right or the board is bad. What would happen if I plugged t2 into t3s plug to see if the temp read normal? (for example). Lastly if you look at the pressures, low is like 135 and high is 280- I am also wondering if the compressor is bad. There is this constant buzz and I thought it was a contactor coil or something but its not—and coupled with the fact that I get no cold, I get this starving TXV message, and the pressures are crazy, the thought crossed my mind. First things first- I need to get these temps reading right- and then I can move onto step 2. I see in the parts list there is only one part number for thermistors- are they all the same? Thanks
MemberNovember 12, 2020 at 12:14 pm
A, do not move the sensor plugs to the wrong location. You can easily ohm them for a test. But it sounds like a bad one.
MemberNovember 12, 2020 at 12:44 pm
could be a bad TXV, it’s happened before.
MemberNovember 12, 2020 at 12:52 pm
I forgot to mention, that that high of a reading is a shorted probe. Look at the wires were they go through the bulkhead or are clamped for a pinch or rub. Also mice like to gnaw on them this time of year.
MemberNovember 22, 2020 at 9:16 am
HI- thanks- so I changed the 2 questionable thermistors and it solved that problem. ANd interestingly- when I bumped the unit just right- there was a spark- turns out back by the powersupply box there was a wire with a tiny spot of insulation missing. So all comments were appropriate. I called manitowac tec support because it still was not making ice- and wasn’t getting cold. The pressures were crazy and they said “its the compressor”. OK- turns out its under warrranty so I went and got the compressor. Put it in- they are not generous with the silver solder- they give you all of about 6″ —but surprisingly it was exactly enough. Anyway I have a helper primarily because we do a lot of work for property managers and have to carry all of our stuff onto building roofs—. So the new compressor came with 2 caps and a relay. I told him “TAKE A PICTURE–SEVERAL”- then change those 3 parts one wire at a time. After that we disconnected the incoming power so we could move the box out of the way to put compressor in (and filter). Got that done. Went to put everything back- and flipped breaker—immediatley popped with sparks coming out of the unit. So I said “lets see the pictures–we need to make sure these wires are in the correct places”—-he didn’t take any pictures. He said “I did them one at a time”—so frustrating. so I got an ohm meter and undid the wire nuts from cord to unit- and measured the black and white- dead short. Measured black to ground- dead short, white to ground, dead short. So it would seem this should be simple- and what i can determine from schematics it is wired right- ie pin 4 from relay to both caps- and then the other lug on caps is something else- dont remember. I am trying to find a photo or drawing of the cap/relay wiring so I can verify. Its also possible I got a bad relay or cap- so I need to check those.
I have told this guy 100 times- “TAKE A PIC” and it seems like every time I tell him he doesn’t. On air conditioners I know the wiring of them so its less of a big deal but on this I do not—and have to figure it out. I just hope the guy from manitowac was right and it is the compressor because it will really suck if its not. Another interesting thing- my pressures were high—yet I only recovered 15 oz of 404- and it takes 22 oz. I say that because they were really high and yet undercharged—after recovery it was bone dry because when I unhooked my hoses there was nothing left- so it was undercharged by 7 oz. The tech support guy told me if its not getting cold, and pressures are high, it has to be the compressor. OK- whatever you say- but I hope he is right. I still have my doubts—and hope its not that txv or a restriction somewhere—-assuming I can get this short situation resolved- I should know very quickly. The compressor is in, leak checked w nitrogen, evacuated to 400 microns, charged with 22 oz of new 404- so its ready. If anyone has any photos or diagrams of the relay/caps wiring of an iy0524 or equivalent- I would be forever grateful. And just to be certain- the t1 and t2 locations–I want to make sure they are not crossed- (again- no photo–just taken apart). a photo is so simple—and can save so much time and embarrassment and frustration. I guess I should have taken the pics myself- but was distracted by them asking me questions. Ultimately its on me, I should have (from experience) taken the pics myself. Thank you
MemberNovember 22, 2020 at 9:19 am
thanks fixbear- I did get that manual you suggested on 12 november. That was the first thing I did. It is really helpful to be able to download this stuff. Southern Ice (the place I got the compressor) sells them. I didn’t have the heart to tell them you can download free, I am sure they are not big sellers, lol.
MemberNovember 22, 2020 at 12:12 pm
To test a compressor, It’s a simple use of your ohm meter. Most times you’ll find it to be a cap or start relay is the problem. But on some instances you will find that it got liquid from improper service. This usually blows a hole in the cylinder head. But they do sometimes score the piston and seize. I’ve cut dozens open to find the problem. Each brand has it’s common problems. In low temp Copeland rules. Now when it comes to the Danfoss (Secop today) SC’s, They have a oil pump in the top of the compressor to lubricate it due to being designed for shipboard operation. When they were made in Czechoslovakia, They weren’t to bad. But when they moved to China, Quality went way down and I’ve had many seize from lack of lubrication. Being they have mostly been under warranty, I didn’t get to cut any of them apart to find the exact problem. But most had squawked or squealed a bit before total failure. So I knew it was just a question of time.
Don’t overlook that a high resistance electrical connection or supply can cause starting problems as well. If you have a low voltage to the compressor, it may not have the power to start. Remember that starting current is 17 times full load run current. It’s only for a very short time, but needed to get things rolling. One of the reasons that a 17 or 18 amp machine requires a min of a 25 amp breaker and 10 gauge wire for a supply.
It sounds like you may have caused a bit of damage to the wiring or even the controller contacts. Make sure to check the molnex plug on the board.
You didn’t provide the full model and serial number, so I don’t know what version of board you have or if it’s a green model. I originally suspected it to be a “A” or “B”. But being they a warrantying it, it most likely is a “E”.
MemberNovember 22, 2020 at 4:06 pm
You should also realize that the top part of the control board is high voltage and the bottom is low voltage. There should be 7 relays on the high voltage part. 6 in a row and one offset. They control the Compressor contactor, water valve, hot gas, fan, air compressor, water pump, and on remote units the liquid line valve.
The software is different on each model,and has to be loaded with the correct version. always save the original before loading new. sometimes the just aren’t right or corrupt.
MemberNovember 23, 2020 at 11:30 am
thanks. Yes I have seen copelands blow up- and what is strange is when I took this compressor out- it clunked when turned on its side- which with copeland reciprocating is a sure death. So I thought “ah ha”–but then the new one did the same thing. So there is something loose than when tipped bangs into the case.
Its iy0524A-161, and sn is 1120189135
So this is an “A”? It was installed just over 4 yrs ago- July 2016. I am really about done with ice machines, I dont have the experience or expertise- where as I can fix 5 acs or coolers in same time and make much more money. These manitowac units are not bad—-they are very straight forward- what makes it hard to work on is that its sitting on a soda dispenser and so i have to stand on a ladder at an awkward angle. I should have uninstalled it and removed it to a place I could work on it easily. As always- i really appreciate your help. I need to check the parts- make sure that compressor isnt shorted and or any of the new parts.
MemberNovember 23, 2020 at 5:15 pm
I get you on the clunk. All of them hang on springs inside the canister. It’s how much clearance they have and how they pipe the discharge that varies. Most are just a 3/8 copper tube around the outside 3/4 of the way to take the vibration and starting torque.
MemberNovember 23, 2020 at 5:20 pm
Oh yea, the supply power inside the can is also a ribbon cable that goes 3/4 around. Sometimes the rub through from repeated start’s, but only short at the start phase. They’re the hard ones to find. Till they burn open.
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