compressor/evap sizing number check... and problems too !

[knighty]

we have a 26foot freezer at work (the back from a lorry)

original lorry freezer unit as removed (above the cab thing) and a 2nd hand (6months old normal freezer room system) system was fitted to the side of the box...

it's been running great for about 4 years.... but we decided to move (slide) the box forward a few feet to make more room... and when we did the solenoid on the liquid line entering the box caught on a roof joist and bent the pipe a bit.... the freezer still ran ok, but wasn't bringing temp down as quick as normal... the pipe wasn't kinked, just a bit bent/restricted...

so i phoned the refridg. guy we normally used and asked him to come take a look when he was in the area (as there was no hurry)... he came a couple of days later and had a quick look...

I thought i could have probably bent the pipe back straight... but i didn't want to risk cracking it / making it leak and he agreed.... as it was bent right where it went into the solenoid he just disconnected the pipe, shortened it an 2inchs and re-conected... (he added some gas too, saying losing some was inevitable)

(remember it was running pretty much ok at this point, could hold -18'C without any real problems)....

he was pretty late fixing it so I didn't really have any time to check it was running ok....

the next morning when i came in it was only down to -13'C ! and didn't manage to get any lower than that all day... then the next morning... it was still only -13'C...

(mornings are the best time for temp checking for us... as we open the door a lot during the day... i always check the freezers in the morning and make sure they they're down to temp)


so i phoned him back up...but he couldn't make it out for a couple of days as he was already fully booked up... he didn't want to recommend anyone (which is understandable tbh).. so i picked the closest place to me in the phone book i could find....

the guy came out and had a look..... he thought maybe the first guy had let some moisture into the system or added the wrong kind of gas...

(which seamed reasonable to me)

I talked to him for while... but he made a couple of mistakes while i was there... he didn't recognise that the compressor had a delta star starter (for the 3 phase) and thought that the extra contacts/timer were for the defrost and that the defrost was permanently on... (it wasn't)

he also thought the compressor wasn't shutting off when he turned the defrost clock round to defrost... when really it was just pumping down (it was pretty obv. from the sound of the compressor that this is what was happening)

this new guy said that the compressor is a good one and pretty new (i checked the label after he went and it said year 2000) but that the evap. is old undersized junk and needs replacing....

can someone check and see if these are sized right ?
he was pretty keen to fit a new evep for me... but because it's worked perfectly for 4 years I'm not sure what to think....

from the compressor I have....

Copeland
Glacier
Model: ZF15K4E - TDF - 551
Serial Number: 00B291982 C

and from the evap...

Friga - Bohn
LUC 650 STH NF
SER 0009F
SER 0127D


are these units sized correctly ?

any ideas on what could be causing the problems ?

the 2nd guy added a little more gas and the room is down to -16'C on a morning... but no lower...

someone has written R22 on the evap... but this 2nd guy said maybe the gas had been changed after that was written (before I had it)

he said a new evap and changing to 404A would make a massive differance....

sorry to ramble on and talk so much.... I'm dyslexic.. sometimes the details don't come out in the right order / so if I don't ramble i miss things out !

thanks in advance !

Alan :-)