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  • MANITOWAC IY0524A—alert, T4, starving txv, ice probe

     fixbear updated 5 months ago 4 Members · 39 Posts
  • mtsaz100

    Member
    November 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

  • fixbear

    Member
    November 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.

  • fixbear

    Member
    November 12, 2020 at 12:20 pm

    you may want to check this for values

  • olivero

    Member
    November 12, 2020 at 12:44 pm

    could be a bad TXV, it’s happened before.

  • fixbear

    Member
    November 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.

  • mtsaz100

    Member
    November 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

  • mtsaz100

    Member
    November 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.

  • fixbear

    Member
    November 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”.

  • fixbear

    Member
    November 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.

  • mtsaz100

    Member
    November 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.

    Thanks again.

  • fixbear

    Member
    November 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.

  • fixbear

    Member
    November 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.

  • mtsaz100

    Member
    November 27, 2020 at 3:02 pm

    So I changed the compressor- and the pressures are messed up still Manitowoc said “if the pressures are that high (125/245) it “HAS TO BE THE COMPRESSOR”–so i changed it. Then he said “well it can only be the hot gas valve”.

    Is this the hot gas valve?

    Manitowoc Ice 000007028 Service Valve Sol Evul3 230V 3

    Mines 120V- but these seem to be on backorder everywhere. You cant even get thse on ebay or amazon!

    • olivero

      Member
      November 27, 2020 at 4:23 pm

      Wow, gotta love that.

      You’re sure it’s not the TXV?

      I would think you could somehow verify if the hot gas valve is staying open or not closing properly.

  • fixbear

    Member
    November 27, 2020 at 7:51 pm

    Why do you say the pressures are high? R-404 does run high, but the hot gas valve has nothing to do with it unless it is leaking and you have a low head pressure. You need to check the cooling of the condenser if the head is high. Dirty, fan speed and air movement, Measure the top and bottom temps to be certain. Don’t forget that the control senses the head temp at compressor discharge to cycle the fan to keep the head up in cooler ambient temps. You can go in the service menu and read the temp that it is seeing.

  • nafets47

    Member
    November 28, 2020 at 10:01 am

    This maybe a dumb question. But have you checked what the pressures are supposed to be for the unit? It seems that whoever it is that you are talking to at Manitowac doesnt know what they are talking about as they keep saying replace parts which is not resulting in the thing working.

    On one of the refrigerators I worked on recently the pressures were unusually high for most
    refrigerators but it ended up being correct for that unit. So I would
    ask next time you call their tech support to speak with one of their
    supervisors to verify what the pressures are actually supposed to be. In
    my case it ended up being just a bad fan.

    If the ice machine was working, and (assuming) without issue before you were called it should be something simple. There are not that many parts to the unit.

    Have you checked voltage from the wall throughout the unit to verify you are getting the correct voltage to the end? Also have you checked amps draw on the compressor, is it correct level?

    One of my ice machines, tech support told me to replace part after part. I am talking, board, float sensor, temp sensor, float stem, etc. In the end it was just a stuck flow switch that once cleaned resulted in the whole unit running fine and now I have a bunch of parts which are totally fine sitting on my shelf because I expected these people to know what they were talking about. If I had just put in a bit more time, verified and checked voltage and ohms throughout the unit, I would have saved a bunch of time and money for the client.

    Last thing, did you check the capacitors?

    • fixbear

      Member
      November 30, 2020 at 11:48 am

      They are published in the tech manual above. But here is a quick referance;

  • fixbear

    Member
    November 28, 2020 at 6:54 pm

    Tell us what the pressures are and where in the cycle the machine is at the time of measurement.

    With ice machines, the suction pressure is constantly changing from a high point at the beginning of freeze to a low point just before harvest. It then goes up drastically during the harvest (hot gas defrost).

    Remember that any added water during the freeze cycle will prevent ice making. The capacity of the compressor will not make up the heat loss from and water coming in and going down the overflow..

  • olivero

    Member
    November 29, 2020 at 11:48 am

    I’m thinking TXV or hot gas defrost, it can’t be anything else at this point, something is leaking by.

    You could remove the hot gas defrost and braze the tube shut, then try it and see if it works, if it does, then you know it’s the hot gas, if not, it’s the TXV.

    • fixbear

      Member
      November 30, 2020 at 11:33 am

      Olivero, I can’t agree with that method. Besides being invasive to the system and very labor intensive, There are easyier ways. Like a clamp on temp probe. If you have two, put one on the compressor discharge near the compressor. Use the other to compare flow at the hot gas valve and downstream of the tee for the evaporator. If there is a leak, it will be very obvious.

  • mtsaz100

    Member
    November 30, 2020 at 3:11 pm

    It stays at 125/245 ish. High I haven’t paid as much attention to but it’s close to that

    • fixbear

      Member
      November 30, 2020 at 8:54 pm

      OK, 125 is a long way away from 245. Your talking 60F or 108F compressor discharge. And that should be close to T1. No where near high pressure in that system. Basically what your saying is the the room ambient is cool and the fan switch is coming on at 240 psi. Close to where it belongs. But to cool of a room to function as designed efficiently.

  • mtsaz100

    Member
    November 30, 2020 at 3:13 pm

    What is hot gas valve called where is it snd how do I pinch it off per Brandon at manitowac

  • fixbear

    Member
    November 30, 2020 at 8:39 pm

    Hot gas valve is also called the harvest valve or defrost valve. On your machine it is on a line tee from the compressor discharge, through a strainer then the out side tee’s into the evaporator inlet. It’s not really necessary to pinch it off if you know that you are in ice mode and just feel the discharge side of it. Should be cool. If it’s hot, it’s leaking.

    If you don’t have a pinch-off tool. you will need one in the future. It squeezes the line down to seal it and then has a set of dies to make it back round and open. It’s used on ice machines to change out the fan switch without removing the charge. But also all the new coolers, they have no tap nor are we allowed to leave a tap on after charging anymore. So you crimp it down, cut off the end of the process tube, braze on a temp fitting. squeeze it back open to charge. Then squeeze it back, unbraze, and braze shut the process tube.

    • mtsaz100

      Member
      December 1, 2020 at 10:29 am

      I was unable to type- for some dumb reason so I typed a word doc- then loaded it But thats a hassle. Anyway- basically I said “yes I have a pinch off tool- but didn’t know what brandon from manitowac tech support was talking about when he said “pinch it off”. I like your idea Fixbear- to see if one side is hot or not. Also I used my yellow test coil and removed white coil for a second- it melted. BUT evaporator got cold.

      Can i change the “harvest valve” while unit is in the machine on a soda fountain—or would i be better off taking it down and putting it on a work bench (i know answer)—I just want to know if its doable or not. I have concerns about getting good solid leak free joints.

      Also, welbilt gave me about 6″ of solder to use on compressor- “56% silver solder with flux core” Does anyone know what that product is? I want to buy some—it was so incredibly easy and I can use air acetylene because it didn’t need as much heat as sil fos. It was awesome.

      At first I thought “wow they are chintsy” but the little bit they gave me was exactly enough–I think I had about 1/4″ left over when compressor AND new filter were installed. So technically I had extra.

  • mtsaz100

    Member
    December 1, 2020 at 10:34 am

    My computer won’t let me type anything to post. The file I loaded says that I removed the white coil snd used yellow cps test magnet. Ice machine got cold but no water running so no ice. Anyway after 1-2 min that white coil melted. Not sure what that means. Yes I have pinch off tool I just didn’t know what the guy meant.

    • fixbear

      Member
      December 1, 2020 at 11:58 am

      He is thinking that the defrost solenoid valve is leaking during ice making. By pinching it off, it’s eliminated from the cooling circuit. But just feeling it will tell you if it’s leaking.

      White coil?

  • mtsaz100

    Member
    December 1, 2020 at 10:40 am

    This is what I meant by 125/245. I was wrong it’s 145. It won’t load pic of my gauges but low is 145. High is 245 so I didn’t mean 145-245 I meant low snd high pressures

    • fixbear

      Member
      December 1, 2020 at 11:54 am

      Those are normal operating head pressures.

  • mtsaz100

    Member
    December 1, 2020 at 1:23 pm

    Brandon says you will never make ice w those pressure. Obviously I trust you much more. It has exactly 22 oz of 404 (spec) snd I pumped it down to 300 microns. Why did white coil melt when removed and magnet put on harvest valve?

    • olivero

      Member
      December 1, 2020 at 1:52 pm

      Oh no.

      Did you pull the coil off the solenoid when it was active? That’s that it sounds like.

      A solenoid valve is in simple terms a valve that’s opened by a magnetic field. It has a plunger inside the valve that you don’t see, the white thing (the coil) is copper wound in a circle many times, when it’s energized, it generates a magnetic field which pulls the plunger inside the valve up, allowing flow.

      If you pull the coil off when it’s energized or it gets energized with nothing in it, it overheats and melts.

      That’s what it sounds like happened.

      Fixbear is right, his way is better than mine, just feel the discharge side of the hot gas valve (Harvest valve) and see if it’s warm when it’s making ice, if it is (it would have to be warm further than just right at the valve for it to be leaking)

      At 145 PSI you’ll never make ice, it’s too hot. it’s over 60*F

      I’m betting on the TXV or contaminated refrigerant, did you put virgin refrigerant in when you charged it?

  • mtsaz100

    Member
    December 1, 2020 at 4:31 pm

    Refrigerant is new. The charge is correct. I thought txv but manitowac said no that it’s impossible or suction would be like 10 psi or less. Also he said under 7 degrees in snd out difference is good

  • fixbear

    Member
    December 1, 2020 at 7:34 pm

    That coil should not be powered in the ice making cycle. Only the harvest cycle. We are still talking about a 520 pound air cooled Indigo right? And the harvest valve. If you are now working on another remote condenser, That’s a whole different animal.

    When there is no armature to absorb the created magnetic field, You are just creating a short. Like hooking a wire across a battery. When using a artificial magnet to open the valve, make sure to unplug the coil.. If the defrost coil is powered in the ice making cycle, you found your problem. Miss-wire or bad control relay.

    I don’t know what you told Manitowoc, but that head pressure will make ice. I only have a small portion of information on what you see and have done. They are a closely balanced system that makes ice very well with low energy. Make sure you understand the operation in the manual and what effects what.

  • olivero

    Member
    December 1, 2020 at 8:17 pm

    Fixbear,

    Head might be good but the suction is way high.

    MTsaz, Look, Manufactuers tech support have the same chance as we do in guessing what’s right, difference is, we’re still doing it, they are not. Some of those guys are just following a chart, some of them know what they are talking about but not all of them.

    I’ve had multiple instances of tech support telling me “Oh, it’s the “Insert expensive part here”. ” only to find out it’s not.

    High/Normal head. WAY high suction.

    Only thing it can mean is somehow you are getting high side refrigerant into the low side, that’s 1 or 2 things.

    TXV OR hot gas/harvest solenoid.

    There’s nothing else.

    If your refrigerant is virgin 404, then it’s not fractionated which believe me, can lead to some confusing numbers like what you got.

    So what is it?

    Either the TXV or the harvest solenoid.

    Feel the inlet vs the outlet of the harvest solenoid when the machine is making ice, as in, water is running down the evap and the comp is on. If the outlet is hot, the valve is leaking, feel it further downstream, is it still hot? at 245 PSIG your line should be somewhere around 100*F plus minus a little, I believe it’s teed right off the discharge line of the comp, not the condenser so it should be about pretty hot.

    Did you kill the coil of the solenoid? You didn’t answer that.

    If it ain’t hot, it ain’t the problem and it’s your TXV.

    I’ve seen 1 TXV go bad on a dual evap ice machine, one evap was making ice, the other wasn’t. I felt the outlet of the hot gas valve, it wasn’t hot. Good, it was the TXV, replaced the TXV and all was well.

  • mtsaz100

    Member
    December 3, 2020 at 1:04 pm

    It’s virgin 404. I changed the harvest valve snd new coil doing same thing. So Brandon at manitowac what say you now? Per him it’s either compressor or hot gas valve it’s IMPOSSIBLE to be anything else. Well guess what it’s neither. I have a txv but txv feels same temp on in/out. The evap and condenser are same the condenser isn’t hot. The evap isn’t cold. Also the fan doesn’t always run what’s with that? Does condenser have to reach certain temp before it turns on? I was a tech support guy once but the difference being if I told tech abc it didn’t fix it I was on a plane. My suspicion is Brandon probably knows his business but hasn’t worked on anything other than in the factory for many years. Anyway I will try txv but I would never suspect it in an air conditioner and if I did would probably rep with a piston if it was an old unit Here goes the txv

  • mtsaz100

    Member
    December 3, 2020 at 1:18 pm

    This thing is now going crazy. The fan looks like it wants to turn on very slight movement. Also the evap is hot. Steam was coming out. This is all new before I did anything but came in today. I don’t get it at all.

  • olivero

    Member
    December 4, 2020 at 10:55 am

    I’m so utterly lost in what you’ve done.

    So you changed the compressor, harvest valve/hot gas valve and now want to change the TXV.

    If the TXV feels the same on the in and out. IT’S BROKEN!

    The TXV is supposed to drop your high side waaaaay down into the low side where it’s now freaking cold, that outlet pipe is supposed to be frozen when it’s running.

    The condenser fan cycles to maintain head pressure, it’s a common thing on ice machines, Scotsman does it that way too.

    If your evap is hot, the hot gas valve is either open or your TXV is wide open allowing hot liquid to go through, but that shouldn’t be possible due to how they are built.

    Try pulling the wires off the harvest solenoid valve but leave the coil on the valve so it doesen’t fry. Then see what happens.

    Steam was coming out? Steam from what? Mist, Vapor? Refrigerant blown into atmospheric pressure?

  • fixbear

    Member
    December 4, 2020 at 1:32 pm

    Ok, if the evaporator is hot, the hot gas valve is open. Did you check the power to the valve? It should not have power except in defrost. Perhaps when you had the wiring problem something got crossed or the control welded the contacts for the valve.

    It sounds like your doing a lot of parts changing without real troubleshooting. There are flow charts in the manual I gave you for that purpose.

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