r 404 A

[bratosin]

hI Guys. Can you tell me if a sisten filed With 404 has a leak i have to replace all the refrigerant quantity or i just refil the missing quantity. Best Regards.

[cadwaladr]

where on the system did it leak from how much does the system hold in total,if it leaked from liquid side top it up,if leaked in vapour side you may have to recharge

[taz24]

.

404 has a very low glide. Less than a degree I think and all commercial large systems in the UK supermarket trade have refrigerant added to them once the leak is repaired.

It is a commercial descision. If you are dealing in 10's of Kg's per system then no ill effect would be noticed for the most part across most tempreature ranges between -35 and 0 deg C.

With 404 you would only notice the difference if you were using it at extreem temps.

If you ask me for the text book answer then it is a Zeotropic and it should be pulled and replaced with new if there is any doubt about its composition, but you don't want the text book answer you want an oppinion ;)



taz.

.

[lowcool]

all the above,but i would be inclined to top up with r507,r404 is r507 with 3 parts of 134a added.only to enable the maker to get around the patent etc.507 is more beneficial in high ambient condensing

[ice_p]

How much time have you got???? Top up!

[Coolie]

How much time have you got???? Top up!
And this is why F-gas regs are coming into force soon.
To get rid of the cowboys who are too lazy to perform a proper repair.

It is already illegal to top up without repairing the leak!

If in doubt, take the refrigerant out!

[chuckblouse]

I am looking for the proper procedure to replace an R12 system with a R404A system.

[freezetech]

do it the correct way by the book less haslle no comebacks f-gas regs state system must run at max efficiency so you decide

[chemi-cool]

I am looking for the proper procedure to replace an R12 system with a R404A system.

You will need a new condensing unit.
Compressor and condenser will need to be changed,

The system have to be cleaned from mineral oil, a new TXV, drier and receiver.

The suction line on R12 is usually too big for R404.

Consider replacing the whole old unit to a new one.

[Peter_1]

And this is why F-gas regs are coming into force soon.
To get rid of the cowboys who are too lazy to perform a proper repair.

It is already illegal to top up without repairing the leak!

If in doubt, take the refrigerant out!

He didn't say he hasn't repair the leak

[bratosin]

Thanks guys I use 404 in a chiler
mounted on an ice rink and has condenser leak. Leak will be repaired. Thank you very much for your advice

[Tayters]

I've repaired many a leak on supermarket systems that use R404A.

Every time found and repaired the leak then top up as required. As others have said the glide is small so you can get away with it.

Remember if the leak is in a liquid part then equal parts of the different gases will be lost.
If the leak is where you have a liquid/gas mixture (i.e. evaporator or condensor) then you could well lose only a certian part of the mixture.

So what happens if the leak is in a soley a gas part of the system?

I've been told equal parts as per a liquid leak get lost, but to my mind the mixture isn't chemically bonded so more of one part could be lost.

How do you chaps see it?

Cheers,

Andy

[monkey spanners]

I think if its leaking when its gliding thats when it can leak in unequal parts so in the evap or condenser.

If its a capillary system i'd put a fresh charge in but anything bigger i'd add to what was left in the system.

[raz5]

up to 3kg then its a balance of probabilities to top up or replace, over 3kg then we all know what we have to do in the UK !!!!!

Now if we were in differing parts of the world this thread would be over in seconds :D :D

[Lodiev]

The best way to see if your gas is still in speck is to boil off some liquid in a small container and measure the temperature at 0 psi, then take your temperature pressure ruler and see if the temperature are within 10% as per manufacturers specks. If not recover the refrigerant and replace with new charge. ( depending of total charge in system)