Porkka cold rooms

[Andy AC]

Hello guys, I've got a couple of porkka cold rooms to recharge, one fridge on r12, one freezer on r502. For some bizarre reason both of the monoblocs were degassed when the cold rooms were dismantled.
The problem is that the cold rooms are still in their dismantled state for shipping so I won't be able to run them down to temp and do a full check on them when they are running
I'm going to put R408a in the freezer and R409a in the fridge, can I put the same amount of gas in as on the data plates or would I need slightly more or less?
The other problem I have just been told about is that the bloke I am doing it for has sold them both as fridges, he didn't know that one was a freezer. Apart from adjusting the eliwell control and compressor life being compromised is there anything else that I would need to do to it?

[Latte]

Andy,

Charge to data plate weight LESS 10% and you should be ok. You are obviously aware of the compressor problem, but you cant do anything about that.
Regards

Fatboy

[Andy AC]

Thanks Fatboy, charging them less 10%, is that on both of them or just the freezer?

Andy

[monkey spanners]

Both of them, the blends weigh less pint for pint compared with the old cfc refrigerants.

[davecool]

hi andy

yea i would agree with that. i would also rest the controller defrost settings on the freezer to just operate on fan defrost only for about 30 mins every 6 six hours with a couple mins drip time which may in turn may give the comp a bit extra life time as i beleive that some of these porkka rooms were hot gas defrost

[Mark]

I have never weighed the gas in when retrofitting refrigerants on small modular coldrooms.
If your porkka rooms are on HG defrost charge it up to around 10 psi and leave it for a while, then activate a manual defrost monitoring the compressor run amps and operating pressures, if its overcharged you will see and hear it if its undercharged the same.
With Kind regards
Mark

[hhbref2003]

When working with blend of the 400 series, it is important to charge in liquid form to ensure that the right blend mixture is used in the system otherwise your unit will not provide the required temperature expected.

About the weight it can be the same yes, but again, unless you have taken prior precaution during charging you may find out that you have overcharged the system