UV Dye leak detection additive in large systems

[dogma]

Hi guys, I have a freezer room with a nuisance leak that I can not find. THe system has a bank of 3 large Bitzer semi's on it and holds a refrigerant charge of about 95kg of R404a.

Is it safe to use moon shine or another leak detection additive in such a large system?? I know it would have to be charged into the high side of the system to reduce the amount coming back through the oil sep and logging in the compressors.

1 Engineer has told me NOT to use such an additive.. What is the thoughts of the RE community?

Regards

Dogma

[Rob White]

.

I'm in two minds about the stuff.

Personally I hate any make and all makes of leak detection additive.
I have used them in the past and they have caused more problems than
they solved.

In my opinion you should never put anything into the system that the
manufacturer does not put in and they don't come supplied with the stuff.

That all said and done, they do work and they do find leaks.

My experience with them is in supermarket packs and these leak detect dyes
caused no end of problems with oil return, valve's choking, and acid.

The supermarket packs were a bit leaky and there was sometimes a moisture
problem which was bad enough, combine that stuff and it was like "light the blue
touch paper and stand back" took a long time to rectify lots of niggly faults that
showed up afterwards.

One good thing they are great for........

Mark the apprentices forehead with the stuff and watch him glow in the night club :D
Not that I would do that to any one (much) :D

Rob

.

[cadwaladr]

i guess overdosing the system would be the main issue

[chemi-cool]

I would recover all the refrigerant and pump it with OFN + helium,than with patience and soap find the leak.

[install monkey]

if you put spectroline dye in the system you will find all sorts of leaks,but on the negative side, you'll get covered in it, and everyone elses gauges will get covered in dye, if found tricky leaks on compressor terminal plates,bellows on pressure switches,end plates on evap coils, flare nuts when operating under normal conditions.

[Goober]

Less is more with this stuff! Patience and proper procedure when inserting. It is great for finding leaks. Maybe offer a oil change on compressor down the line to dilute the stuff once you have found your leaks...

[dogma]

The biggest problem I have is the twin evaps are 24 feet off the ground..... and at -30 deg. C is slippery and dangerous work on a ladder or in a forklift bucket....

[THE DUDE]

Im not a fan of any additives. I had 1 Rack with a Dye in it, cant say I found any more leaks from the Dye than with a Electronic Leak detector.

[joe-ice]

When this stuff came out first i seen it seize a big bitzer ,granted too much was put into the system. I have also seen it block alot of expansion valves.point being it sticks to everything even moving parts.I would not use it in any system,also doubt if warranty would be honoured if you sent a compressor back with that stuff stuck to it

[cadwaladr]

fork lift buckets are not allowed anymore

[joe-ice]

As bart simpson said it wasnt me,but in fairness to the guy he put in what supplier told him,as regards the blocked valves it was the correct amount,no fun pulling valves at 3 o clock in the morning

[Tycho]

We have been using it on a R-507 system with a 3000 kg charge of refrigerant, it's been running for 10 years now with no problems.

The biggest issue with the dye is that some people think it's universal and that is what causes problems. As long as you find a dye that is compatible with both the refrigerant and oil you are using (not just one of them :)), you shouldn't experience any problems.

The downside with it is that it gives the oil a very "distinctive" smell, and that any oil spill in the machinery room is harder to clean up unless the floor is painted :)

[chilliwilly]

If you have a long horizontal run like you have and its high up and the floor is slippery. The die would be the best option, if you don't spot the leak straight away, it will eventually start to come through the armorflex. Especially if the joints haven't been flagged and the installers have used up all their **** ends of pipe.

One of the guys that I laboured and was apprenticed to years ago, would have me rast and joint 2 foot long **** ends of pipe. Luckily because I was conscientious with brazing, they didn't leak. Which was just as well as they weren't flagged where they were.

[rumberger]

i have used my h10 to find many impossible leaks, if you can shut it down and recover 404, put 20# r22(soo sensitive to h10) in and pressurize, shut off suction bvs and let equalize at 300# with patience you will find leak