Fridoblock FK24 no cooling from main evap?

Fridoblock FK24 on a 27ft freezer body, with extra evap inside

it's running off the truck on the floor hooked up to mains 3 phase

was delivered a week ago, has been on and running 2 days, was filled with frozen meat... which is starting to defrost

was only running the main evap - I don't normally use the 2nd evap, they don't defrost well when running as a freezer, I don't *think* the drain lines are heated?

air probes on main evap air supply/return show temp difference of around 1'C - could just be error in reading?

running the 2nd evap it has approx. 6'C temp difference

suction/liquid lines at 2nd evap showed 28psi/260psi

can't see an easy to access suction port at the compressor or main evap?

with only the main evap running the sight flash was flashing a lot

it got dark/cold/wet so I gave up, looking again tomorrow

it turned itself onto defrost, by time I walked around from inside (20sec? 30sec?) there was a steady steam of water from main evap defrost.... hadn't been time for ice to melt, so assuming it was trapped condensation?

can anyone give me an idea of what to look for?

I would guess a stuck/ or broken solenoid/coil - but if that was the case I'm surprised it ran at all and didn't trip off on the pressure controls?

awwww I got excited for a reply there and it's just spam :-(

The solenoids are very delicate, if you have to force one off they bend very easy and then they can get stuck intermitently.

Check the main evap fan is running the right way, and that the plastic fan barrel to motor shaft coupling hasnt snapped or damaged the motor shaft keyway. The plastic can somehow stay intact and the motor shaft keyway gives up.

Should be able to get the sightglass to clear. Easiest thing is to recover the charge and compare it to the data plate, their normally pritty close to the labelled charge. Main charge + Remote Evap charge.
If you pump the unit down into the receiver, if I remember you should fill the receiver sightglass.

The Remote evap might have daft wee heater tapes inside the drain tubes, cant remember.

If the phase rotation on your supply is wrong, they can still run, just the evap fan runs backwards and the condenser fan gets spun the wrong way.

hi

thanks for the help

I called someone out who's used to working on these - needed it going asap

he diagnosed low charge, added 4kg (8lb 13oz) (didn't recover it to check charge)

it was weird to me that the rear unit would cool but the front unit wouldn't... he said he's seen that a lot

said it needed more but was scared to add more - truck boxy had been standing a long time before it was delivered to me - he said it's normal for the compressor shaft seals to dry out and for them to leak, but didn't want to add more in case there was another leak somewhere

unit was up and running after that

that was yesterday..... today the compressor is dead!

100lb on both suction and discharge line at compressor, and compressor is easy to spin by hand, no resistance there

:-(

Quote:

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Originally Posted by knighty

hi

thanks for the help

I called someone out who's used to working on these - needed it going asap

he diagnosed low charge, added 4kg (8lb 13oz) (didn't recover it to check charge)

it was weird to me that the rear unit would cool but the front unit wouldn't... he said he's seen that a lot
Cant remember, but they probably have their own solenoids for cooling and defrost. Could be a few reasons for it only cooling the rear, including phase rotation. If the main evap fan runs backwards it does very little air movement.

said it needed more but was scared to add more - truck boxy had been standing a long time before it was delivered to me - he said it's normal for the compressor shaft seals to dry out and for them to leak, but didn't want to add more in case there was another leak somewhere
Yer, you need to give them a wee run every so often if the units not in use for a period.

unit was up and running after that

that was yesterday..... today the compressor is dead!

100lb on both suction and discharge line at compressor, and compressor is easy to spin by hand, no resistance there
Depending on what the problem ends up being. The compressors arnt too complicated and once you lift them out the unit it should be easy enough to work on if you need to do anything more than a valve plate change. If needed parts should be not to hard to source from a transport fridge company.

:-(

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.............

I took the head off, no movement on pistons when I spin the front pully

pistons were tiff but I pushed one down a little, the other didn't move

must have destroyed the crank shaft?

either way it's dead :-(

trying to source another :-o