Troubleshooting tips for a couple of ice machines

These tube ice makers are versatile.But certain warnings in the operating instructions need to be understood and adhered to.
A few months ago we got a request from the management to increase the wall thickness of the cylindrical ice.There are 2 defrost initiation low pressure controls.The righthand one is for cylinder ice, the lefthand one for crushed ice.They wanted me to increase the thickness leaving little or no hole in the center.The recommendation is a minimum of 1/2 inch center hole.This reduces ware on the cutting blade, lessens the chance of freeze-up due insuficient water return, and prevents liquid freon returning to the compressor.
Ice production was down.After ruling out a number of other possibilities it became apparent that iiiiiit was partially frozen inside the evaporator.This consists of a refrigerated insulated jacket containing a number of tubes for the water circulation.As the temperature drops, it forms ice on the walls of the tubes.
When the low pressure drops to the set point on the LP switch, it opens a solenoid valve that allows hot gas from the compressor discharge to start to melt the ice tube allowing it to drop by gravity where a metal cutter slices the tube into usable sections.There is normally a continuous cascade of ice during the defrost time 0f 3-5minutes.[hence my video lingering on the ice falling should I need to make my point to the "powers that be" that it is making as much ice as it can now].
It took nearly 2 days to defrost the frozen tubes by adding hot water to the reservoir tank and allowing it to circulate without refrigeration.
Fortunately no damge was caused to the cutter, deflector plate or compressor.
Ice machines are not the most popular refrigeration appliance with refrigeration engineers.You need infinite patience to see the machine through its entire ice making cycle making small adjustments to ice thickness, defrost time.When I entered the refrigeration field many years ago, it was after complting a 4 year Ministry of Defence" electrical/mechanical apprenticeship.We studied everything from computer building[nand and nor logic] electro plating. machining, fabrication engineering craft practice, circuit board manufacture and a number of other disciplines.Also day-release for City & Guilds courses in the subjects we showed most promise in.
One of the favourite question/answer scenario was "What does an engineer always do?" My answer was "think" to which our instructor replied"we would hope you did that automatically, Laurie!" The answer was "CHECK!"
So that's what I've always tried to do.
o8--07-2009:update.
It always used to come on to defrost at 36PSI.Even after replacing the compressor head, it would not drop below 41PSI back pressure,We made a full pump-down on the system and left the ice jacket on vacuum for a night.The next day the receiver level had dropped by 11/2 cm.We then by-passed the heat exchangers.Just in case there was migration of liquid from the liquid line to the suction.After re-positioning the T.E.V. phial bulb, it came down to 34 PSI but the ice was too heavy.Careful adjustment brought the ice cycle to 8 minutes at 37PSI.
There are a number of these ice machines in Eilat.I know of 3 others about the same age, 15 years.So we know what to look for next time.

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[romaurie]

And so it appears this fault was not an isolated case.2 more machines in this locale have now been modded to maintain ice production.

[romaurie]

It has all been explained in the text.

There was a leak in the suction accumulator from the liquid line heat exchanger.

By-passed and re-located the sensor.

[ducky69918]

Really not a helpful video.

[xShadow125]

science...

[steve171274]

2.14 and the bin has ice in it.....er.. theres nothing to see here, i'm moving on.... maybe u could do a vid on how to 'reclaim time'. : )

[steve171274]

I'm 1.17 in and nothing's happened.....right back to the action.

[brianburkard]

Hey great video! I appreciate you taking the time to make a video on the Vogt Tube Ice maker. I learned a lot from it and it should help me when working on tube ice makers in the future. Keep up the good work.