Foster walk in freezer

[ActiveEngineer]

Help required,

Working on a foster walk in freezer offshore and am ready to charge the sytem but i have no scales.

the system requires 0.980kg of R404a to be added which i will have to do by hand.

Am not sure what the LP running pressure should be.
looking for a rough running pressure i can work to

note...No access fitting to HP


Foster

Model:SP301LW

Can anyone help

[multisync]

the kitchens must have a weighing machine?

otherwise yurn the bottle upsidedown and count one mississippi for 50gms. Then charge to the frost line. Get it down to temp let it cut out on the stat twice to make sure it's settled and see it ice back -assuming it is a cap system a tev one will have a s/g

[ActiveEngineer]

Good point,

But ive checked and they dont sadly.

[bernard]

Hi charge to 1 bar

Regards Bernard

[ActiveEngineer]

Thanks bernard i do have a comparator but i am unsure how to use it.

I take its the vapour were looking at, So slide it along to 1 bar looking at the pabs/Pe or at the top we have psia? psig which one would it be ? and that would give you your running temp.

[bernard]

Hi

Use PSIG,with cap tube I always take the temp I want to acheive which in your case is -21 then add -12 = -33 which is approx 1 bar. Charge very slowly ensuring you don,t have liquid back on compressor.This all depends on condition of coil.I find this better than using scales as a lot of the time the weight is in correct from manufacturer.

Regards Bernard

[Andy AC]

Make sure the condenser coil is clean - give it a good wash, it will make your life easier.

Andy

[Rotax100uk]

also try to charge with the front cover on as much as possible with these foster units too if not pressure readings will not be accurate