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Abe
14-04-2001, 12:40 AM
The domestic market now has frost free gizmo type refrigerators with fans, electronics, heaters, sensors, etc. how does an engineer keep up his technical repair skills, bearing in mind that the principles of refrigeration remain the same. Do engineers working on new cabinets have any particular stories, tips, etc on domestics?

Dan
20-04-2001, 03:38 AM
Straight out of trade school, I moonlighted with domestic refrigerators. I did well, at least I thought so. I was usually following up behind established contractors who were quoting prices at half to above the replacement value of the fridge.

I found mostly that the start relay was bad or the defrost timer was bad. Technicians always missed a bad start relay for some reason. I was a hero maybe 30% of the time compressors were condemned. But I was charging little and desiring to learn more than I was desiring to make a living.

Now I am one of those established contractors... the one's desiring to make a living.

Driving to a home with a truck filled with inventory to repair a domestic refrigerator is not a way to make a living, if you are in the repair business. Might be if you are in the replacement business though.

Domestic refrigerators reside in the disposal category when they break and cannot be fixed within an hour and and easy replacement of a cheap component you have on hand.

I hadn't thought of this until now: Maybe you are at the disposal end of the game and repairing fridges for resell.

That could be workable. I can't help you there, but I think I could figure out ways to make the new fridges work like the old ones did. Forget the electronics, unless you want to swap boards with what you have.

Dan


[Edited by Dan on 07-05-2001 at 05:20 AM]

Abe
20-04-2001, 06:47 PM
I take on board your advice, and cant agree with you more.

Have a good Day

Abe

[Edited by Abe on 06-05-2001 at 08:48 AM]

Dan
10-05-2001, 04:26 AM
Maybe this question doesn't belong here, but here is where I came up with it.

You have a refrigerator that loses temperature. You notice that it is cycling on its overload. How much time and money did you already spend on this service call? How much more time would you estimate you would have to spend to diagnose it thoroughly?

And lastly, what steps and in what order, would you take to accomplish this?

Dan

subzero*psia
14-05-2001, 05:56 PM
If this is an older unit and it were definitely cycling on overload, right off hand there are two things I would immediately check. Start components and how clean the condenser coil is. Obviously the condenser coil would be the first thing, then start components. Since I had the components off... I would check the compressor windings if the coil was clean and if the start components were good. I just had this happen.... it was a commercial undercounter unit. I found the windings were open. Total time I spent was about 20 minutes... I gave them a quote to change the compressor $762.00 including labor... they thought that was high so they checked with other servicers and got approximately the same quote. I came back the next day and billed them my minimum charge of $50.00. The restaurant owner decided to buy a used unit for $350.00 from someplace.... how do you beat that???

Dan
14-05-2001, 11:42 PM
Sounds like a well handled service call, Subzero. If the windings checked out good, what would have been your next step?

Dan

subzero*psia
15-05-2001, 01:55 PM
Well, condenser coil is clean, start components are good, compressor windings are okay...

Is the overload tripping on amperage or thermal would be my next question. Check the amperage if okay and unit trips suspect compressor is overheating feel and check with thermocouples... I have found most compressors run about 140 to 160 degrees Fahrenhiet in 70 to 90 degree ambients. At this point I may begin to suspect refrigerant charge... I would check my evaporator coil condition and fans/amperages... also do a visual check and touchy feely on the capillary tube for a cold spot but this isn't normal with a tripping o.l. and probably one of the last things that I would suspect which has bit many technicians in the arse is to find low voltage to the unit itself. This can happen if the power supply is a parallel circuit. I have seen many units in the field where several appliances were all running on one circuit breaker. This unit I am supposing is domestic and not commercial so I wouldn't normally suspect an overloaded circuit though. I would think all this including the afore mentioned items could be accomplished well within and hour easily enough if everything is accessible.

I believe within this answer you would locate your problem... if not then I would perform a leak check with a sniffer, then ask the end-user if they would want to continue the diagnosis if no leak is found but inform them that I suspect internal damage may have occured such as acid formation, extra driers and multiple flushing may be required, if they still want to continue, solder an access fitting onto the process stub and gently sqeeze the crimp only enough to allow pressure to be read through my gages... a sweat on saddle valve would also be needed... I would check my pressures, compression ratio etc.

On a domestic unit it is possible that air entered the system if a leak is on the low side... egad... a major cleanup... not worth the time, parts and effort on a domestic unit usually. Heck alot of times owners of commercial equipment balk at a major issue. I have to say this, I have NEVER seen air in a commercial unit unless someone was careless with their gage set. I am an avid supporter of quick disconnects on manifold gage sets and multiple manifold gage sets... if you can afford it get a set for each type of refrigerant you plan to work with.

Well, I am sorry if I ran off with this. Anything further you would have suggested Dan? Perhaps there is a bugger you have seen that we/I haven't and we/I need a heads up?

Dan
19-05-2001, 01:39 AM
Originally posted by subzero*psia
Well, condenser coil is clean, start components are good, compressor windings are okay...

Is the overload tripping on amperage or thermal would be my next question. Check the amperage if okay and unit trips suspect compressor is overheating feel and check with thermocouples... I have found most compressors run about 140 to 160 degrees Fahrenhiet in 70 to 90 degree ambients.

That's a handy observation, Sub.

At this point I may begin to suspect refrigerant charge... I would check my evaporator coil condition and fans/amperages... also do a visual check and touchy feely on the capillary tube for a cold spot but this isn't normal with a tripping o.l. and probably one of the last things that I would suspect which has bit many technicians in the arse is to find low voltage to the unit itself. This can happen if the power supply is a parallel circuit. I have seen many units in the field where several appliances were all running on one circuit breaker. This unit I am supposing is domestic and not commercial so I wouldn't normally suspect an overloaded circuit though.


I agree. In commercial work, I find this quite common and it eats up technicians. The trick there is to watch the voltage during startup. Undersized wire, shared neutrals and stuff come to mind regarding voltage in commercial equipment. Especially 230 volt compressors on a 208 circuit.


I would think all this including the afore mentioned items could be accomplished well within and hour easily enough if everything is accessible.

I believe within this answer you would locate your problem... if not then I would perform a leak check with a sniffer, then ask the end-user if they would want to continue the diagnosis if no leak is found but inform them that I suspect internal damage may have occured such as acid formation, extra driers and multiple flushing may be required, if they still want to continue, solder an access fitting onto the process stub and gently sqeeze the crimp only enough to allow pressure to be read through my gages... a sweat on saddle valve would also be needed... I would check my pressures, compression ratio etc.

On a domestic unit it is possible that air entered the system if a leak is on the low side... egad... a major cleanup... not worth the time, parts and effort on a domestic unit usually. Heck alot of times owners of commercial equipment balk at a major issue. I have to say this, I have NEVER seen air in a commercial unit unless someone was careless with their gage set. I am an avid supporter of quick disconnects on manifold gage sets and multiple manifold gage sets... if you can afford it get a set for each type of refrigerant you plan to work with.

Well, I am sorry if I ran off with this. Anything further you would have suggested Dan? Perhaps there is a bugger you have seen that we/I haven't and we/I need a heads up?






I think that is a fine domestic service call you ran, subzero. That you did it within 2 hours is impressive, too. The bugger that I had most often seen is the current sensing relay failing.

To eliminate that from my troubleshooting curiosities, I fashioned a three wire extension cord with spade connectors and a toggle switch on the lead to the start winding. It was surprising how many condemned compressors I found to be okay that way. But in retrospect, I probably should have been able to diagnose a bad relay more simply. It has been a long time since I worked on domestic stuff. I am thinking all I needed to do was put an ammeter on the start winding, but couldn't do it easily for some reason.

I have no light to shed beyond that. I think your last post is a fine example of best practice while troubleshooting a domestic - or even commercial, single phase, self-contained - refrigerator.

Thanks for your contribution, Subzero.

Dan

subzero*psia
19-05-2001, 08:47 PM
You and I both mentioned the time.... I have to be honest. I listen to service managers grumble about their techs only getting 4 or 5 calls in a eight hour day... that should be the last thing they worry about. I think 4 or 5 calls a day is normal, on some days that is darned impressive! If a contractor has techs making 8 calls in an 8 hour day... they are parts changers and wouldn't know the difference between system, mechanical, environmental or electrical symptoms causing a failure. I would rather see a tech take his time and get it right, charge the customer for an accurate diagnosis and repair, forget the "service charge or truck charge" that many servicers add onto every service call. I finally put a statement at the bottom of our bills that states the minimum charge regardless of whether service is rendored or not and I never have a problem with it, in fact I get more work now.

Dan
19-05-2001, 10:40 PM
Subzero, how much of your service work is related to domestic refrigeration or residential service?

I am astonished that a manager would expect more than 4 service calls a day from a technician. I am in the commercial end, but I still want to hold onto a feel for the residential end.

Dan

Dan
26-05-2001, 03:46 AM
Sheesh. I am replying to myself. Come on peoples.

This week, my service guys just got hammered. A dipping cabinet, a roll-around spot display case, and one of those stainless food prep cases.

The dipping cabinet had a leak. First tech did a good job finding it, but overcharged it. Here is the interesting part, and I suppose why a dial-a-charge is so important with self-contained equipment.

He was savvy enough to check frostline and condenser subcooling as he recharged the unit. He was confident he understood this stuff, and really wasn't far off the mark. What killed him was this:

He pulled the condensing unit out to service it and made all of his measurements with a condensing unit that will never breathe such free air again. Then he tucked it into its hot spot home and we had hell to pay the next day.

The stainless steel food prep unit. A good tech ran this call, COD. He came back telling me not to send him on any more COD calls. (He referred to them as "Cussed Out Dammit!) It was a single door unit with a disattached upper door gasket. The evaporator coil had a build up of ice on the top. Let's call him "Ricky" because that's what his name is.... He couldn't be sure whether he had a low charge problem or a gasket problem. No way to measure pressures. He de-iced the coil, ordered a gasket, and collected $75.00 for his efforts. Next day the guy is livid that the unit is still too warm. Sheesh.

The other callback nightmare was our fault. A loose connection on the overload. After replacing a compressor and having several refrigeration failures.

It is impossible to do a thorough and professonal job repairing the equipment that shares the divide between domestic and commercial and make money and achieve a satisfied customer.

Any opinions? Anyone care to start another thread? Hmmmm.

Ice-makers comes to mind.

Dan

subzero*psia
27-05-2001, 02:56 AM
I had been doing service for a small bar down the road, they wanted another ice maker but couldn't afford a new one and asked if I could sell them a used ice maker. Sure why not.... well they agreed to purchase a 400 pound Scotsman I had recently picked up, I was to be able to install and repair the unit before they used it and would pay me when completed.

I installed... should have never connected the wiring but I had to so I could diagnose it. I told them to leave everything alone and not to try using it... they agreed. I came back a couple of days later with parts and found the breaker on and the compressor fried. I knew the owner... I told him what had happened and he was frustrated, I never billed him, but since then I have refused to service their equipment and I will not unless they make a good faith offer to pay for the ruined ice maker in full. It is no loss really... they are hard on their equipment and want everything for practically nothing. I hate bars or pubs... they are real shyt holes when you get to see behind the scenes. I once did service work in the basement of a bar... the owner lived their and had a dog he kept in the basement... shyt all over the place.... I will NEVER service their equipment again for less than twice my normal rate. I HATE bars and pubs... cheap bass turds!

WebRam
27-05-2001, 09:24 AM
Had a bad day then Dean :):):)

Jack Lester
27-05-2001, 05:36 PM
There was apost on another location about customers wanting to help. That and other resons sited in this article.are why I moved to commercial. However,I have found that the user of a product can help you if you ask the right questions. How long has it been down? When did you realize there was a problem etc. I have found that if you LISTEN customers can tell you what the problem is and not know it. Remember your like a Doctor ask questions and your bedside manner matters. Domestic service for 15 years Cascade for 16 years.

Dan
27-05-2001, 06:49 PM
Terrific contribution, Jack! So true. Just last week we almost had a blow up between a technician and the dispatcher. It was a rough week, last week. Anyhow,

The call was frozen food down. The fellow on call drove half across the state to discover that the wide island cases were pulled for cleaning and just thought it would be a good time for a technician to have a look-see. It was not an emergency at all. Communication failure.

Why the technician did not call the customer is the problem I need to address. There are so many things that the customer can help us with. It is frustrating when we fail to use it to advantage.

I hate to admit it, but I prefer a technician with good communication skills and average technical talents to the genius who doesn't ask the right questions from the people who own the equipment that he is servicing.

Dan

Derek
27-05-2001, 08:09 PM
Just for discussion.

Inside of three months you will have a risk of catastrophic failure from a production error. Especially as some manufacturers practice zero final inspection and support a field team for first year warranty which gives excellent 'service image'.
Inside of three years you will have one of the following,

a)blocked drain line
b)damaged seals
c)damage due to operator (knife defrost or removal)
d)damaged doors with both b) and d) caused by rugrats hanging off the doors.
e)blown fuse (more serious fault coming)

Then your thermostat/controls package goes as its designed for x hours to fail 'cause thats good for business.

So cleaning is OK 50 to 75 call out (cheap-discuss)
New seal DIY 30 and scrap in 2 months as they don't ever work IMHE.
Controls 50 to 100 then forget it.

So how about it if can't be fixed in 20 minutes its beyond economic repair. Do you then take the charge for environmental good practice especially if Mr Customer looks like he'd dump it rather than 'dispose of with care'

Or how about the fact that if you never turn them off or move then they go forever and they all die within a year or moving.

subzero*psia
28-05-2001, 12:41 AM
Derek, your last observation does sometimes seem to be the rule... and it is odd too. I have seen exactly that which you refer to. It may be metal flakes in the oil that sits in the tubing and crankcase which gets disturbed during a move and clogs strainers, driers etc. and cause failure in a relatively short time.

Jack Lester
28-05-2001, 04:01 AM
[QUOTE]Originally posted by Derek
Just for discussion.


a)blocked drain line
b)damaged seals
c)damage due to operator (knife defrost or removal)
d)damaged doors with both b) and d) caused by rugrats hanging off the doors.
e)blown fuse (more serious fault coming)



This is what you chose to do for a living so look at it as job security. Talk to the customer reasure them. Tell them to watch Jr, Sell the job. You can do it. I once had a tech that worked for me that said " These darn (Brand) are no good! All I ever see are broken ones" I said, " Be glad it pays your salary" We are in the negative business. No one wants to see us. We are a necessary evil. Smile make it work for you.



[Edited by WebMaster on 28-05-2001 at 10:43 AM]