[lynn comstock]

I use a 40 year old fish scale.

Not so funny. Back in the good old days, that was about the best thing going.
Dial a Charge came next for 10 or 20 years.
Finally we got electronic scales.

When I started, service vacuum pumps did not exist.
I could go on, and on, and on.
It has been a real trip.

 

[lynn comstock]

Only on large systems.

You actually are breaking the EPA regulations.

See http://www.epa.gov/ozone/title6/608/608fact.html

"Major Recordkeeping Requirements
Technicians
servicing appliances that contain 50 or more pounds of refrigerant must provide the owner with an invoice that indicates the amount of refrigerant added to the appliance.
Technicians
must also keep a copy of their proof of certification at their place of business.
Owners or Operators
of appliances that contain 50 or more pounds of refrigerant must keep servicing records documenting the date and type of service, as well as the quantity of refrigerant added.Wholesalerswho sell CFC and HCFC refrigerants must retain invoices that indicate the name of the purchaser, the date of sale, and the quantity of refrigerant purchased."

 

[lynn comstock]

Keep a can of beer in an ice bucket close at hand.
When the suction line is that cold, you have the correct charge.
Now, drink the beer.
:D:

 

[lynn comstock]

what did you do in lieu of vacuum pumps?

• The HVAC compressors were all semihermetic with suction and discharge service valves. (No cans.)
• With the system at atomspheric pressure, and the dicharge service access port on the compressor side of the valve open to the atmosphere
  and the discharge valve nearly closed
• then we would bump the compressor a couple of times and finish closing the dicharge SOV.
• Finally, we would run the compressor for a minute or so to get 28" of vacuum on a compound low pressure gauge. (Microns were unknown at the time.)
• Later when we got canned compressors we used a funcitoning 1/2 hp Copelemetic medium temp compressor for years and years. Change the oil? Never.

System cleanup after a burnout.

• Unknown. We would dump the gas if it smelled nasty, install a new compressor and go.
• We used to blow nasty systems using R-12 as a flush gas. ($0.39 per pound)
• Then we used R-11 for years to flush out systems.
• Suction line driers for system cleanup came along in 1970's. Novel idea.
• Not much change since then except that the arrival of internal compressor motor protection greatly reduced burnouts and nearly eliminated nasty burnouts.

 

[lynn comstock]

It takes 5min to do, why not protect yourself and the system? I myself am a one man show and replace filters every time I open a system up no matter what.

I presume that installing gauges and monitoring system performance is NOT an open system.
If so, I agree. Open system with all the necessary tools and drier at hand...5 minutes....OK.

 

[lynn comstock]

I believe that even with mineral oils, changing the drier was recommended procedure when the system is open. Before the Montreal Protocol, I would often keep open time to a minimum and simply purge with system gas to flush air and moisture that may have entered.

With the new hygroscopic oils, changing the drier is a very good idea.

Sears is Sears and they are protecting their warranty pool. I don't have that concern.

 

[lynn comstock]

I think your 1 in 10 for a cap tube problem is still high. I think I run closer to 1 in 100.

jim

I often have followed techs who added gas every year to a system that had a small leak somewhere that they could not find. Almost always the small leak was not. The cap tubes were gradually getting varnished on the inside and adding refrigerant fixed the "problem."

Condenser ambient, maintenance history and age of the systems that you care for makes a big difference on how often you may see this problem.

 

[lynn comstock]

I don't think anyone will argue about how beneficial changing the filters is. I think replacing all electric controls after a compressor failure would be even more beneficial, would you do that also?
There has to be a balance between perfection and efficiency. Sometimes telling the customer that a unit is not worth fixing is more business savvy than attacking the unit full force. Agreed I am sorry I don't also agree that replacing a filter is a 5 minute job. If all tools and the drier are at hand, this is close to a bench job. Maybe on a bench. I am probably saving my knees and back a couple of hundred hours a year extra abuse by not replacing filters on every system opened to air.
Hey I am not criticizing anyone's business conduct. This is the way I do it. I am continually changing my ways of doing this work, striving for efficiency and customer satisfaction since I am only a one man operation and my only method of making customers is word of mouth. The rules are different when you have employees with less skill and knowledge than you have.
PS. Can you expand on 'Sears protecting their warranty pool' ? I think changing filters at every compressor replacement job would serve that purpose better, no?

Agreed, but if Sears is paying, they get to choose what they pay for and accept the risks.

 

[lynn comstock]

Where is Trance?

 

[lynn comstock]

If a system holds less than 50 pounds of refrigerant, there is no record keeping requirement.