[Poodle Head Mikey]

Can you tell me the procedure they use ?

What is the procedure for changing by compressor amps?

How do you do that?

What are you looking for in regards to a fully-charged system?

PHM
--------

. . . I've heard other techs who charge by amps also

 

[54regcab]

You can't charge by compressor amps alone, but by using a manufacturer chart you verify if amp draw is close to what it should be. Every compressor will draw a different amount of amps based on SST and SCT, and you don't know the SCT/SST without hooking up the gauges. Attached is an example, I used the compressor on my own system which is "Rated @ 13.5A". As you see under normal conditions it pulls about 1/2 that.

 

[waterdawg]

What is the procedure for changing by compressor amps?

How do you do that?

What are you looking for in regards to a fully-charged system?

PHM
--------

There is no way to charge by amp draw. But it can be used as one of many diagnostic tools. As far as 410 IMO treat it the same as 22 but pressure is higher is all, remember high pressure switches are now set around the 600-650 range :0. SH and SC ranges have not changed. And oh ya dont use the sight glass if there is one, you'll overcharge the unit . More care with evac procedures and purging is required to limit scaling in my experience. Have had a higher failure rate with reversing and tx valves but that could be crap product as well.

 

[dsprice]

FLA is max amps plus 10%. Not the same as RLA. If you are hitting FLA, You are about to loose your compressor. If its a piston pump, kiss it goodbye...especially with 410. The oil is breaking down and hermatics are not as forgiving as scrolls. Make sure to check for voltage loss at contactor, capacitor and relays before condemning the compressor. That was a hard lesson for me to learn.

No, you can not charge a system based on amps. This is, as stated, a diagnostic tool. When charging by subcool, you are measuring your liquid column. That's all...no magic involved. Pressures don't mean a thing. Type of refrigerant doesn't matter. A liquid column is a liquid column.

When charging by super heat, you are measuring the change in temperature at coil as liquid changes to gas. Again, type of refrigerant and pressures don't mean a thing. Super heat is still just super heat.

No matter which method is used to charge a system, you need to check and monitor both to ensure its working like it should. Personally, I use a dual port type k with 2 clamps so I can read both as I go.

I've said this here before. We are not in the pressure control industry, we are in the temperature control industry. Learn to stop putting so much emphasis on pressures. Pressure is for reference to convert to temperature.

Sent from my SCH-I535 using Tapatalk 2

 

[GT1980]

54 and DS:

COOOOOOOL!

and but I can charge by amps (capable); and I may so do with say a prep table refrigerator replacement start up max 11 oz 1/3 hp compressor r134... to just clip max amps rla (not FLA)
in an 80-deg cabinet in a hot kitchen start up...

NEVER with any ht p ever by amps.

~ Wikipedia has FLA and not RLA and FLA is AFL ! go search. Write an edit with your references for the world.

 

[Poodle Head Mikey]

So just a straight hose and an amp clamp and I'm good to go? Nice. I am getting tired of hauling all these tools around. It should be more like golf were you have your caddy do all the heavy lifting.

PHM
------

54 and DS:

COOOOOOOL!

and but I can charge by amps (capable); and I may so do with say a prep table refrigerator replacement start up max 11 oz 1/3 hp compressor r134... to just clip max amps rla (not FLA)
in an 80-deg cabinet in a hot kitchen start up...

NEVER with any ht p ever by amps.

~ Wikipedia has FLA and not RLA and FLA is AFL ! go search. Write an edit with your references for the world.

 

[glennac]

Give up? OK; I'll just tell you: Full Load Amps. <g>

So when does that occur? Answer: when the compressor is doing all it's motor will allow / tolerate / handle without overheating.

How much is that? Somewhere around it highest suction pressure and highest discharge numbers. Which for typical A/C compressor might be about 140º condensing and 50º evaporating temps.

5o any lesser conditions require less power, take fewer amps, and are why you seldom see a normally operating compressor near the limit expressed by Full Load Amps.

BTW: I might be wrong but I have always taken FLA and RLA as pretty much the same thing for my purposes. Please correct me if I am wrong about that.

But anyway; that's why you see fewer amps than the FLA ratings.

PHM
--------

You are correct sir. Thank you very much

"RLA: Acronym for "rated load amps". The maximum current a compressor should draw under any operating conditions. Often mistakenly called running load amps which leads people to believe, incorrectly, that the compressor should always pull these amps. You should never use the listed RLA to determine if the compressor is running properly or to condemn a compressor. The running amps of a compressor are determined by the evaporator temperature, condensing temperature and the line voltage.

FLA - Full Load Amps: Changed in 1976 to "RLA - Rated Load Amps"."

 

[GT1980]

NEVER with any ht p ever by amps.

ya got it , right?

like yo' candor!
T's again.

 

[Chuck]

NEVER with any ht p ever by amps.

ya got it , right?

like yo' candor!
T's again.

Ok

???

 

[GT1980]

Ever use hot gas super-heat?

If ya can before he's gone, talk to Larry Pippin I met on the ph in 1981, the Bristol Compressor Co super knowledgeable of many sorts. He shared in general heat pump conditions, GT, that range of hot gas super-heat, and bottom of a recip "tepid"ness to feel for... works great charging by amps on sm compressors, and by bag full of tools your really just tryin' to unload.

 

[GT1980]

Ever use hot gas super-heat?

If ya can before he's gone, talk to Larry Pippin I met on the ph in 1981, the Bristol Compressor Co super knowledgeable of many sorts. He shared in general heat pump conditions, GT, that range of hot gas super-heat, and bottom of a recip "tepid"ness to feel for... works great charging by amps on sm compressors, and by bag full of tools your really just tryin' to unload.

 

[ReferYankee]

Not to get off topic, where are you from GT?