Brazing in compressors?

[troymedhurst]

Does anyone else expierience lots of oil and vapour when brazing compressors etc...

When I de-cant a system I always pull into a slight vac and then add nitrogen to 0psi, but whenever I un-braze a joint I always get a flame of vapour and seem to attract alot of oil. Even while I am brazing in the new compressor I can see vapour burning off, until joint is complete. This is always puts me on edge a little bit.
All the lads I work with are not bothered by this and say I worry to much, but I dont particularly like flames coming out of pipework, not the least because it is not very good for the old chest!

What are your expieriences?

Are there any ideas you could give me to minimize this?

Am I just worrying over a normal occurance?

Many thanks for any replys

[chemi-cool]

Your health is the most important thing.

It is better to cut the pipes next to the compressor then to un-braze them.

Burned oil and refrigerants is dangerous, do your best to avoid it.

Try to braze against the wind, this way you always breath fresh air.

[Brian_UK]

As Chemi says, cut the pipes, most compressor suppliers will state that in their instructions.

[troymedhurst]

Thanks for the replys

I have tried this before, cutting closer to the compressor and removing,but even when I am un-brazing the female copper (off the system pipwork) I still get vapour burning off.
Do you guys get this?

[Quality]

Yes quite a common thing but you must purge with nitrogen whilst brazing any way so you should not get any vapour

[DEVIL]

well purging or not, the residual oil on the inside pipe at the place were you do the work will allays be there , you can't make it move, that's the behavior of oil.
so , use a mask or be as far as possible , make the flame be powerful so it doesn't take a lot of time and unbraze it so you don't make the heat travel true the pipe so you don't get the oil angry , just a little bit messed up :))

[rude]

This is possibly one of the worst parts of the job. It feels like it burns your nasal cavities when you breath it in.

Just try doing it with as much ventilation as you can.

[wingman]

Whenever I have to desolder a compressor, I open up -if possible - a shraeder valve or something like that and use nitrogen while brazing. But when it's not possible to purge nitrogren I cut and remove.

Brazing is something I always do under continious nitrogen flow.

[lees8110]

What sort of masks can you get for this?

I have seen the type you put batteries in and its like a pump on your belt, which ppumps fresh air into your face mask.

Does anybody have any experiance with these?

[Deniver45]

MAN, WHAT ARE PEOPLE BRAZING THESE HUGE SUCTION AT THE COMPRESSOR WITH?

By the way I used a new 3-M mask today with changeble filters ( $20 for the filters ) for doing a "quick-flush" I bought from LOWES ( hardware store ) which is in the paint department there. Where does it this mask get the fresh air = a line set? Cause; if you need a mask, chances are you are in a box cleaning a coil or doing a flush like I did.

I am PISSED though brazing this 3 ton Copeland in though! MAN, I ALWAYS use oxy - acetyline, and all the lines when great; I TOO cut most everything out that I can, because the harris 15 will make a ball, or flow and that stuff IS HARD as a rock to cut back = need a grinder! WELL I RAN OUT OF ACETYLINE @ 4:40 PM.
Anyway, I have too say that I need staybrite 8 or something for this suction AT the compressor joint! Isn't staybrite 8 = 95/5% silver? DAMN, the mess, man I always make FUN of guys who braze like that AND NOW I AM ONE OF THEM! $HIT, no matter what I did, it would NOT melt down! So then I went and bought one of those "Turbo torches" and have to asy after I let go of $300 ( $120 for the tank and gas ), THAT THING IS JUNK! = PIECE OF CRAP! I want my money back, I hope Barker will give me my $300 back!

HOW in God's name does anyone braze with that thing? You know it turned my Harris 15 ( finally ) into a "spreadable" type of pasty braze................IT would NOT flow! And it is around 93 out today.

I was doing a HUGE beer cooler in a convenience / party store that got hit by lightning. THIS guy had the condensing unit ON the floor, not grounded or on wood out back IN THE RAIN , with NO cover over the electronics! Do you know there was no potential relay there? it was gone, blown to hell. The Furnas contactor ( obsolte ) = fried, The 60amp breaker had 3 of 4 males tongs left; the start cap=gone, the RUSTED run cap OHMED good, but the terminals were swollen. So after I did the electronics, I fired her up and a FLAME shot out of the 3 loop cover! Man, I KNOW better, I am the guy who walks around all day thinking " this is a thinking man's game" and HEY to those white collar guys. I knew to ohm the 3 loops, but AFTER it shot out. I did disconnect all three, and got 118V, and and a small number from start to run, but "OL" and "OL" to the common to run and start.

MAN, WHAT ARE PEOPLE BRAZING THESE HUGE SUCTION AT THE COMPRESSOR WITH?

Talk, man, by all means you guys talk!@

[Brian_UK]

Up your silver content.

[monkey spanners]

Whut mah' homey Brian said, also if ah' am runnin' low on da oxy ace, i'll use mah' mapp to'ch on de smalla' connecshuns and save da damn oxy fo' de bigga' joints. In an emergency ah' have used two to'ches t'get some joint hot enough and den plum kep' de double barrel to'ch on it while ah' brazed. De dree loop doodad, be dat da damn compresso' terminals? makes ya realise how dangerous de stuff we wo'k wid be, stay safe man! Right on!
Danks fo' de haids down on de max' gots'ta look into digtin' one.

Monkey :cool:

[mikeref]

All brazing can be difficult when working on opperational systems, always that residual oil and fumes then the solder refuses to run around the back of the join that my flame can't get to so i position a mirror and proceed but now all hand movements are back to front!? Further comments on brazing with residual oil and refrigerant are for another time.. mike

[paul_h]

Whut mah' homey Brian said, also if ah' am runnin' low on da oxy ace, i'll use mah' mapp to'ch on de smalla' connecshuns and save da damn oxy fo' de bigga' joints. In an emergency ah' have used two to'ches t'get some joint hot enough and den plum kep' de double barrel to'ch on it while ah' brazed. De dree loop doodad, be dat da damn compresso' terminals? makes ya realise how dangerous de stuff we wo'k wid be, stay safe man! Right on!
Danks fo' de haids down on de max' gots'ta look into digtin' one.

Monkey :cool:
LOL

Deniver45 if the rod isn't flowing, more heat, sanding off the oxidation before brazing, higher silver content rod or flux on the joint, whatever is applicable to the situation depending on the metal of the material, size of pipe etc.

[Deniver45]

NOW THE BREAKER KEEPS POPPING! I ohmed everything out, ONLY 1 CD fan was not replaced , but OHMED @ 34 like the other NIB. . ..........I dropped 9 lbs into her and have the crankcase heater on and a heat gun hitting the base of the compressor; Copeland says to run the crankcase heater for 24 hours......REMEMBER, this one was hit by lightning! STILL I have had em up and running fast and don't KNOW why the breaker is popping here. Some terminals were loose, I fixed them all, on the relay, #2 to run cap was a thin wire and replaced it. On the suction joint; I have I found a disimilar metal elbo that is copper coated steel and after we sanded it, the Harris 15 ran right off of it.

SO, I a "captian's hook" ( number 2 good for 7/8 size ) from uniweld and had that brazed with harris 15 in 30 seconds....even less. It flowed like water ( just about ), the thing is with a NEW compressor, i don't like to hold the heat on it too long and of course I have the 3 rags wrapped around it stretched all over the top/side of the compressor. I always use "stay silv" flux and scuff my joints with sanding cloth; the roll I have here is from 1983, and I still have some left. Thanks for the input guys! NOW THE BREAKER IS POPPING I have 118 at common, start and run at the compressor, I ahve the condenser fans out of the cicuit...still popping the breaker. IF anyone has any advice, I will take it!

[monkey spanners]

Is it a new breaker, or the original thats been through the lightening strike?

If it all ohms out ok from lives/neutrals to ground then its likely to be an over current issue or a faulty breaker, is there another one you could use temporarily to see is she starts ok, or is this more a sparkys department in the States?

An amp meter with peak hold would be helpfull in diagnosing the fault, don't forget too that there could be a fault in the supply cable from the breaker to the unit, or even the disconnect.

[Deniver45]

Thanks Monkey! what is "is this more a sparkys department in the States?" hehehe. I dumped 10 lbs into a 6 X 12 Parker receiver and 1/2 went to the low side. Right now the crankcase heater is on and a heat gun is on the base of the compressor to boil off the R-22. Thye 2 condenser fans are out of the cicuit. The 3 loops are OFF the compressor and I get my 118 @ common, start and run. I have a Fieldpiece SC77. The 50 220v amp breaker inside was replaced new, the 50 AMP breaker outside was replaced too BUT IT WAS STICKING! it would not reset at first. Some are timed and I do refrigeration, not electricity in walls, but HERE IS THE THING! This cooler is wired from seperate 110V cicuits in the fuse box, I see this ALL OVER this town! I called a electrician to this job last week, because the line was dead and some of these GE breakers look to be set to "closed", but IT was open, and when he touched it, THEN you could see the "red color" on the breaker = I was IMBARRASED as $HIT! breaker was replaced I am going to do THAT! I will keep this new "Turbo T" and use it for the small 3/8 and smaller joint like you said and save my OXY-ACETY for the 'big boy" 7/8 lines! Tell me more about the braker, I have all the ohm readings here.

"NEVER ASSUME IT IS ONLY 1 PROBLEM!"

[Deniver45]

The one that went through the lightning strike was TOASTED, it had 3 of 4 "tongs" left and that's why I called the electrician last week and he replaced the inside 50 AMP breaker that goes to the 60 amp BREAKER in the disconnect outside at the condensing unit.............the damn thing "sticks", and when i go to reset it, it feels TIGHT like a rusty hinge! Think it is bad? Think THAT is why the 60 amp INSIDE the building is popping? The 60 amp outside was a "fished line" that goes to the box at a 50 amp breaker inside> How do you feel about a 60 amp going INTO a 50 amp inside??

"NEVER ASSUME IT IS ONLY 1 PROBLEM!"

[Deniver45]

BOTH breakers were replaced, BUT we have a 60 amp 110V @ disconnect outside, going into a 50 amp 220V into the breaker box. The 60 amp outside was ROASTED and the 4th 'tong" was gone................I THINK that new breaker they put in is, NOT right becasue when I go to reset it, it feels like a rusty hinge!

[Deniver45]

You know , you got me thinking here. ...something just hit me = when I have the compressor out of the circuit and the 3 terminals OFF the compressor ( 118v each ), the 2 fans run (connected to the contactor, and NOT the relay ) and my voltage is good at the start cap 118, run cap 118 and the relay 5 to ground = 118V. IT MUST be the common wire from the contactor ( T1) to the compressor!, The NEW compressor ohms out fine and I have 3 X 118V at those lines. It got hit at the "common from the compressor to the T1" and I took it half way out and it LOOKS OK, but will remove IT and ohm it too. In think the terminal at the end of "common" is bent too and not making FULL contact on that compressor.

[monkey spanners]

I am unfamiliar with the way your equipment is wired in the States, i belive you have single phase 110v and neutral supplies and two phase 220v with two lives which go to run the higher power stuff such as aircon etc.

Over here we have 240v and neutal supplies and thats it for domestic. Only commercial buildings get three phase 415v supplies.

If my understanding is correct you will have one phase to the common terminal and another phase to the run terminal and the start terminal via the capacitor. If the system has any ptc start kits i'd bin them especially if they were there when it got struck, the comp should have its factory supplied starting devices only, or a propper potential relay and seperate start cap/run cap (something like a 5 2 1).

Have a look at this guys and similar channels, there are quite a few good vids on youtube about fault finding air con systems.

http://www.youtube.com/watch?v=6IiIIMcAVGE&feature=related


http://www.youtube.com/watch?v=A_7kO2jVETY&feature=channel

Jon :)