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Grizzly
02-03-2008, 11:30 AM
CALL-OUT
How many of you have been called out to a fault, to find that once you get there. The fault is not with the fridge plant!
An Instructor of a fault finding course. I was once on, so say simulated a fault. For me to eventually admit that I could not find one..... Answer there was not one!
He said "It will happen!" How True!
Likewise whilst travelling to site you think the problem over. Generally the more you know about the system and the further the distance travelled. Equals
Disaster!
I have driven long distances believing that there was a major rebuild at the end of it. To discover a milliamp control fuse blown.


One of the best I can describe, shortened to preserve everyones sanity. HONEST GUYS!

Industrial Ammonia Ice plant, 4 sets of plates producing approx 80ton of Ice per 24hrs.
Plates no 4 furthest away from liquid pumps and surge drum.
Have historicaly produced less than the others. Liquid starvation to the flooded plates is perseved.
Over an 18month period the production drops to virtually nothing.

We and anyone else we know who has ever had anything to do with these type of plant are totally lost as to the cause (Including the Manufacturers Finsam of Norway).
PM, Solenoid and non-return Valves, Compressors etc. etc. are all overhauled.
Eventually the Plant operators decided that enough was enough and payed for a Engineer to come over from Norway.

When he arrives on a Monday afternoon. I receive a phone call to say that he believes.
One of the Compressors I overhauled earlier in the year is at fault and could I attend site to discuss this with him in the morning. oh merde!

I phone my boss saying this is all going to get very messy and potentually expensive.
I have a very very sleepless night and despite the 75 ml drive was on the Jetty at 06.30 hrs the next day. To be met by the Site Engineer who said " don't worry it is not the Compressor.
In fact he and his colleagues don't know what it is". ARGH!!!

So during the course of that morning we look at everything again. He talks some more over the phone to his colleagues ( like an except from the Swedish Chef..Sorry Viking and Tyco!)
As luck would have it whilst the other 2 were fridge plant checking.
I decided to look elsewhere and noticed that the water manifold on plates 4. Were not sweating anything like the others and the tank water was overflowing.
Also the water was 5-6c warmer than its neighbor.

I was assured by the visiting Engineer that this was purely due to the fact that the plates were short of refrigerant and therby cooling less.
But he conceeded that the unecessary topping up of the tank with warmer ambient water could have a negitive effect.

So we turned of the water and drained the tank sufficiently to adjust the water ball****.
Whilst doing this I noticed a 3/4 inch plastic water pipe.That came into the side of the tank and dropped down into the water.
Just in front of the suction of the water pump supplying the plates.

When questioned the Site Engineer explained that.
It was something that his. then boss. Had done 15yrs ago or more.
And he felt it was something to do with the condensor water.

It turned out to be the head cooling water, which being mains fed. Had gone through Sabroe SMC-108
Compressors (2) and was then being deposited in front of the pump.
So although the tank water was only 5-6 c warmer, this could be 30c, 40c, 50c or more!

Apparantly all 4 tanks used to share this heat load, but when the original head cooling pump failed.
The pipework was modified and plate 4 took all the load.
When we removed the offending pipe Ice was being produced within minutes!!!!

I don't know which was bigger that day my head or smile..
Sorry its so long guys it's a tale worth telling and don't forget the moral of the tale.
IT'S NOT ALLWAYS THE FRIDGE PLANT OR AS BAD AS YOU MAY THINK!
Grizzly

US Iceman
03-03-2008, 01:41 AM
Thanks for sharing that story Grizzly. I hope others spend the time to read it closely as there is an important lesson to be learned for sure!

Josip
03-03-2008, 08:45 AM
Hi, Grizzly :)



CALL-OUT
How many of you have been called out to a fault, to find that once you get there. The fault is not with the fridge plant!......


........When we removed the offending pipe Ice was being produced within minutes!!!!

I don't know which was bigger that day my head or smile..
Sorry its so long guys it's a tale worth telling and don't forget the moral of the tale.
IT'S NOT ALLWAYS THE FRIDGE PLANT OR AS BAD AS YOU MAY THINK!
Grizzly

Good one..... something to remember.....

Best regards, Josip :)

expat
03-03-2008, 09:54 PM
This is indeed a good lesson and reminds me of your old sig, US Iceman, about not being able to see the wood for the trees.

I think we get bogged down sometimes with where the problem could be coming from, as pertaining to our knowledge, rather than starting the trouble shoot with a more common sense approach that would be applied by an intelligent but less knowledgeable person. Lets be honest, how many of us have had plenty of time to mull over the symptoms in our head on the way to site and get that tingly feeling when you think you've cracked it even before you get there. Most of the time you get there and realize you were barking up the wrong tree from the start. But, sometimes you keep on in your misguided direction only to have the humbling experience of having the on site apprentice point at a switch and say "What if we tried turning it on?"