Compressor Pack Troubleshooting

[iceman007]

I had an interesting conversation with the area manager for a few supermarkets the other day, and thought nothing else of it. Well, I've been offered the service work for these outlets, the only problem being that some of them run on compressor packs. Anything else would not normally be a problem at all, but most of my refrigeration work is either coldrooms, chillers, dairy cabinets etc, such as Norpe, Verco and so on. I could use the extra work, but have to admit to being a little cautious about these packs. I had always thought that the only tangible difference was the control circuits-refrigeration basics are the same.

One of the supermarkets is having a problem with not being able to maintain a temperature, and I am in two minds whether to have a go on Monday or not. In any event, I feel that perhaps I could use a bit of technical support on these packs, and should maybe do a course in Supermarket Refrigeration.

Regards
James

[shogun7]

Iceman007, You know you have to do it, because the challenge is there, besides you have the support of this web site and people like Adolf O’Brien, Richard, Peter, Chemi, Prof and all the other great intellectuals and of course ..me! Oh and I almost forgot Gary the salesman. If you aren't making any mistakes, it's a sure sign you're playing it too safe.

[rbartlett]

it depends how much 'free time' you have packs eat up time like no tomorrow..

a few years ago we got a call for a supermarket pack that had lost a couple of compressors
muggins here didn't take a step back quick enough and was left holding the baby.

luckily for us,me and the customer marc was available so i took him along..

without him i really was a basket case in there..see pic

have a go for sure -but don't live to regret it..

cheers

richard

[Mark]

Hi iceman

Think of a pack as a large condensing unit but with remote condenser .
Basically Most packs do one thing only, maintain a suction and discharge set point.The tricky part is finding out the other variables associated with faults in supermarket refrigeration.
What you could try is suggesting to the customer that you will take on a few stores if he is prepared to pay for a maintenance visit first.
That will give you a chance to check out the stores pack,alarm history and frequency(if available),case/equiptment condition ,then go back to the customer and put forward your suggestions.
On what basis would they pay fully comprehensive or per call out.
Bare this all in mind before making a decision
Best regards Mark

[Latte]

.

One of the supermarkets is having a problem with not being able to maintain a temperature, and I am in two minds whether to have a go on Monday or not. In any event, I feel that perhaps I could use a bit of technical support on these packs, and should maybe do a course in Supermarket Refrigeration.

Regards
James[/QUOTE]


Course on Supermarket Regrigeration ?

At the end of the day the best way to learn is get in there and do it. all you have to remember is the principals are the same. Are all the compressors running, if not why not.
One thing to remember is that Supermarkets are notorious for not having enough condensing capability. Are the cases struggling since it has got hot or for longer than that. Whats the maintainence been like, Driers old, If TEV's and store has had leaks poss orrifices partially blocked. Gas level low.
There is nothing too new here that i am sure you wouldn't be able to sort if you have the time but you have to weigh it up. If you are self employed is it worth it or can you make more sticking with the small units. If you decide to go for it good luck it will certainly keep you busy over the summer months and you may fine you enjoy this sort of work more.

Regards

Raymond

[chemi-cool]

hi James,

some people have that special sense to locate problems real quick by looking and feeling pipes and compressor heads.

Others start to learn the system and go by some unwritten book and it take them ages to find something wrong.

Where would you place yourself?

multi compressors packs will supply you with many little problems that depend on the type and make of the controller.

Usually, its those basic, not too smart systems that will last and a new ,state of the art controller might make you jump for service if a little mouse was running under a compressor .

you will have to make a decision of how you get the bread on the table.

From what other guys say, its a one way street.

Whatever your decision is go for it with open eyes.

Chemi

[iceman007]

Wow !!

Thanks for all your replies.
To answer your question Chemi, I would consider myself as being in the category of being able to find most faults as well as being adaptable.

The only caution I have is from going from commercial refigeration, such as chillers and dairy cases to this. Compressor packs is just about the only thing I have not yet really ventured into. The basics I know are the same, but I'm a little cautious over the controls and capacity controls etc.

I know I have to do this, because it will make me feel more complete being able to master packs and larger supermarket racks. I had thought about doing some training on more than one occassion, but am not convinced it's the answer. I've always believed that on the job experience is the best way of learning, but I suppose a short training seminar would be a good confidence booster- it certainly was when I started doing large chillers a while ago.

Thanks to you all for taking the time to reply. Much appreciated.

Kindest Regards
James

[dill]

James, out of interest what is on the pack ie. compressor type,hp and number off, how many cases, cold rooms does it supply and what type of control does it use iether electronic transducers or a simple kp switch controling the suction pressure? I would say give it a go and if you get stuck there are some top blokes on this site who will be glad to help dill.

[iceman007]

Hi Dill
Can't give you all the info until i've been. Didn't have to go today but will probably be going tomorrow or Wednesday. Had another problem witha dairy cabinet,

Regards
James