High head pressure on Manitowoc startup

[cobitech]

I just changed out a TXV on a J-model Manitowoc ice machine and it was making ice great and I got a call that the high pressure cut-out was tripped.
The pressure will climb high on start-up and trip the cut-out ,but not all the time.
Sometimes it won't trip and run just fine after watching the head pressure climb close to tripping the pressure switch and then it will settle out and run normal pressures.

Do I have non-condensables in the system causing this??
I am new at the ice machine TXV changeout being this was the second one that I participated in changing one out.
The first one is still working fine.

[shogun8]

Nobody can answer that question with the information you have given so here are some possibilities.
Head Pressure Too High:

Refrigerant overcharge.
System operating temperatures.
Non-condensable in system.
condenser coil fins dirty or covered.
condenser fan motor bad.
Plugged liquid line drier.

[ice machine undertaker]

Originally posted by shogun8
Nobody can answer that question with the information you have given so here are some possibilities.
Head Pressure Too High:

Refrigerant overcharge.
System operating temperatures.
Non-condensable in system.
condenser coil fins dirty or covered.
condenser fan motor bad.
Plugged liquid line drier.


Ambient temp too high?

Fred

[shogun8]

I said "some" Fred! of course your correct, thank god we have some people who keep us on our toes :>)

[cobitech]

I appreciate the reply to my question and your right, I didn't give you enough info for you to diagnose the problem I have been having with this machine.

And you gave me the answer I was looking for which was a list of probable causes.
I am leaning toward overcharge or restricted liquid line drier at this point even though I weighed the charge in,I did not change out the liquid line drier due to its tight location. I know that was a no-no,but I didn't.
Now, I have to go back and fix the problem.

Thanks,

[cracker]

Do You Have The Wright Tonage Valve?
Mainas##t Use A Critical Charge......Dump The Charge, Change, The Drier, Follow There Check Out Sheet....Good Luck.

[islandcool]

If you are dealing with watercooled I would be going in that direction first.
Is the water supply on?
Is the water reg functioning?

[cobitech]

It is water cooled and the water supply is on, it could possibly be that the condenser water valve is not feeding right.
I have adjusted on the water condenser valve and got the head pressure to remain steady, but after a day or two I am back to square one with it tripping on high head.
It very well could be the condenser water valve or even the water supply itself.
I am off from work today and will be back tommorow to take a closer look at this.

[rayr]

What is the entering water temp and the leaving water temp.
Those condensers need cleaning from time to time you know.
Bad heat trasfer can result in your scenerio.

[cobitech]

rayr, I don't know the exact temps of the entering and leaving water temps, but it is a noticeable difference.
The entering is sweating cold and the leaving is very warm.

I will check this out today.

How do you clean a water condenser??

[pecmsg]

Are you on a cooling tower or city water???

[Milk man]

Does it trip overnight? You might have some hot water migration and running hot water through the condensor intermitently.

[cobitech]

It's a chilled water loop,that its feeding from. I checked the temperature this morning and this is what I found.
The head pressure was around 265psig,condenser water in was 43° and out was 110°,that about a 65°temp difference.
I adjusted the valve until the head pressure was 210 psig.
43°water in and 80°water temp out.

It's making ice good.
I will keep a check on it every couple of days or more and see what happens.

[cracker]

Sounds Like You Have a Ghost!!!!.....If You can Baby Sit It Try This......Install A Lever Pressure Gauge...The Kind That Has A Moveable Red Pointer......And Watch To See What It Goes To.....If Thats Ok.....You May Have A Weak High Head Pressure Switch Or......A Dirty Water Reg Valve.....Let Us Know.

[meltdown]

someone , might be using the water, robbing yours or tapped into the water system somewhere upstream, Mantiowoc did have some water/pressure regulating valve failures, on cubers water cooled, also, check the hpr, they had troubles on both call their tech support, and give them the mod and serial numbers and ask them if this might be one of those models that had one of these probs, call 800-555-1212 ask for manitowoc or a supply house for their number/distributor, they can help put you in touch with the right headache, and if it doesnt have a condenser fan motor , ask for it from the manufacturer, or wh it didnt come with it!?!

[hiltontech]

How long does the complete cycle take, should be around 18 mins. on avg., try turning the sensor probe 1\4 turn clock wise which will increase your thickness by 1\8 of an inch if it goes into harves only after 10 mins or so.
Make sure you run it on the clean cycle.
Also, if the coils are really dirty take the unit down, clean the coils and the entire inside of the unit, water supply PVC pipe over the grid to make sure you get an even flow over the grid,

[cobitech]

The cycle takes approximately 10 minutes for it to make ice and drop.
The ice machine ran non-stop last night and stopped when the bin was so full of ice that the ice curtain blocked by ice shut the machine off.
Then after they started using ice and the machine started to make ice, it shut off on high head pressure again.

I have tried everything and can't figure it out.
Having someone else look at it and maybe they can figure it out.

[hiltontech]

As I said, try turning the sensor probe 1\4 turn, this will increase the cycle time, this may do it for you.
Let us know, I work on these beast often and they do give you problems at times.

[cobitech]

hiltontech, I will try it, thanks