whats inside (freon)?

[primmers]

i got a customer who had a compressor installed by another guy when i couldnt get there..its a 5hp copeland (MRA2-050A-TFC), anyway the saftey on the reciever let freon out, i replaced the thing, and restarted it, i looked at the TXV and its a R-12...but i have high head psi and low low side, but its running on the t-stat....i dont know what the guy put in it cause he was big on that hotshot stuff....anyway, im wanting to change the filter and put in 401A.

my question is how do u know whats inside and coldnt the expansion valve screw up any guage reading?

[VTP99]

Is not all the refrigerant out of it ?

[primmers]

nope...it lost alot though....when i opened the service valves it started back up, im gona guess the room was about 50 degrees and the low side read 12/15 psi, and the high side around 200+..

i just phoned my customer and told him what id like to do...he'll go for it, but my original question is what bothers me..not knowing what my competitor put in it 6 years ago...my customer will try to find the invoice...

the high side dual psi safety is set to 400 psi........weird.

[VTP99]

Is it for low or med temp app ?

[primmers]

it coOls dead animals..medium..

[Phase Loss]

You can only make an educated guess as to whats in there.

You're doing the right thing by pulling it out and putting in a known refrigerant.

[DLZ Dan]

You can only make an educated guess as to whats in there.

You're doing the right thing by pulling it out and putting in a known refrigerant.

I second that! I use Hot Shot if i see an R-12 TXV. It's a shame now that a tank of it is a small mortgage.

[primmers]

I second that! I use Hot Shot if i see an R-12 TXV. It's a shame now that a tank of it is a small mortgage.

i paid $300 for my last bottle of r-12....my supplier said r22 is $422 a bottle if i buy 10 bottles..

thanks guys..

[VTP99]

I think your going to find that R401a (mp39) is much more then R414b (Hot Shot) Although I do like mp39 for w/i apps.

[primmers]

ive used 401a everywhere, dont wanta change now..

[controldude]

This is a rant rather than a solution but I think r-11, 12, 22, 500, 502 are stll the best refrigerants out there.

[primmers]

yep i agree controldude....

[craig1]

ive used 401a everywhere, dont wanta change now..

then don't change

The worst thing you can do is have different refrigerants at each site. Then you have to carry a whole bunch of bottles around.

I use Hot Shot simply because thats the first r-12 substitute I ever used and never had any problems to justify trying anything else.

[deux]

I miss R12 and R502.

Life was so simple. 3 jugs in the truck. Now I have 50 rainbow coloured tanks in the shop and a hand held digital pres/temp toy. And I never take the right colour tank to the job!

And I cannot recall what a lb of anything sells for. i have chart for that too now!

[VTP99]

I miss R12 and R502.

Life was so simple. 3 jugs in the truck. Now I have 50 rainbow coloured tanks in the shop and a hand held digital pres/temp toy. And I never take the right colour tank to the job!

And I cannot recall what a lb of anything sells for. i have chart for that too now!

Those were the days my friend

[jpsmith1cm]

ive used 401a everywhere, dont wanta change now..

I like 401a.

Good stuff for Med Temp.

I wonder, though, how long before the price becomes prohibitive.

[VTP99]

I like 401a.

Good stuff for Med Temp.

I wonder, though, how long before the price becomes prohibitive.

Last time I checked it was over $$$ must be the 53% R22 in it
Hot Shot was still cheaper @ 50% R22 go figure. There is a cylinder weight difference thou.
I all most always use mp39 for w/i coolers and Hot Shot for small reach-ins.

[Fridge Repairer]

Why is the high side safety set at 400# and why is your head pressure 200 plus...when ever I converted a unit from r-12 to something else. I would complete a triple evacuation similar to what I was taught in school...I would add a small vapor charge and run the unit for a minute then re-evacute...I do this 2 times and the head pressure stays low.

[primmers]

Why is the high side safety set at 400# and why is your head pressure 200 plus...when ever I converted a unit from r-12 to something else. I would complete a triple evacuation similar to what I was taught in school...I would add a small vapor charge and run the unit for a minute then re-evacute...I do this 2 times and the head pressure stays low.

dont know, ive never worked on this system, as i said my competitor did the last compressor change, and he was a fan of using what ever freon he had...

[skpkey9]

To answer your question...

Pump system down and allow condenser fan to run until exhausted air is the same as ambient, then break out your PT chart and check your high side pressure with unit still off and follow it across on your chart and it will let you know what refrigerant is in the system.

PS- will not work if more then one refrigerant is in the system...

Also MP-39 is the better choice....Hot shot is Garbage

Hope this helps...