paul_h
04-12-2007, 01:09 PM
I've been in this game for a while now. Never really studied much theory, down here you do some practical work, learn safety, then you're off on the tools. I've read the books and think I've got some infofrom the, but I never have to apply the theory a lot.
I never really worked with interesting stuff, never seen techical data or manuals written by the suppliers etc.
Most of my work is electrical/electronic. I get manuals with fault codes, I know what pressures and temps to get, and thats it.
I know how to set superheat on TX valve, and to chuck them out if they play up.
So I'm generally a fixer, ie. leak repairer, wiring fault finder.
What to do if you need more than that? (one of the reasons why I joined this forum).
I got sent to a small yacht recently, it has a small condensing unit (model unknown but similar size to a two door glass display cabinet if you're wondering).
It ran two cabinets, the first was a ~100L bar fridge, the second was a tub built into the boats fibreglass on the rear deck, around 40L
Both had universal thermostats hooked up the liquid line solenoids, with the condensing unit cycling on LP control.
Both had small static coils, 3/8 tubing covered by a steel plate. The rear deck tub coil was about 40cm by 50 cm (the tub was about 50cm W x 50 cm H x 30cm D).
And that coil was only on one side, the thermostat was secured to an ajacent fibreglass wall.
The boat owner only recently bought it, and was told the rear deck tub was a freezer.
His problem was it never cycled off, ie. the rear deck tub never got to it's -15C set point.
The condensing unit was OK, the charge seemed OK, the TX valve was hunting (-9 to -16C at the bulb, 60kpa suction pressure)
The TX was a danfoss TF2, R12 model, #01 oriface.
I guess my question is I don't even know if the box with that coil could even get to -15C
Is it just a case of a faulty valve, or bad equipment design. How to find out?
In my personal opinion I couldn't see -15C setpoint happening, this is just a fibreglass tub, the bottom of with the tub in the generator/engine room.
The cold plate was only on one side, the fibreglass wass only 5mm think with no other insulation. The condesing unit was a fair bit newer than anything else, so had been relatively replaced recently. The refrigerant/oil smelt rank, like this unit was about to burn out too.
I've got no idea on whether someone just turned the thermostat down on that tub and pronouced it a freezer or not, hence causing these problems. And I, nor the new owner know if that's the case.
I never really worked with interesting stuff, never seen techical data or manuals written by the suppliers etc.
Most of my work is electrical/electronic. I get manuals with fault codes, I know what pressures and temps to get, and thats it.
I know how to set superheat on TX valve, and to chuck them out if they play up.
So I'm generally a fixer, ie. leak repairer, wiring fault finder.
What to do if you need more than that? (one of the reasons why I joined this forum).
I got sent to a small yacht recently, it has a small condensing unit (model unknown but similar size to a two door glass display cabinet if you're wondering).
It ran two cabinets, the first was a ~100L bar fridge, the second was a tub built into the boats fibreglass on the rear deck, around 40L
Both had universal thermostats hooked up the liquid line solenoids, with the condensing unit cycling on LP control.
Both had small static coils, 3/8 tubing covered by a steel plate. The rear deck tub coil was about 40cm by 50 cm (the tub was about 50cm W x 50 cm H x 30cm D).
And that coil was only on one side, the thermostat was secured to an ajacent fibreglass wall.
The boat owner only recently bought it, and was told the rear deck tub was a freezer.
His problem was it never cycled off, ie. the rear deck tub never got to it's -15C set point.
The condensing unit was OK, the charge seemed OK, the TX valve was hunting (-9 to -16C at the bulb, 60kpa suction pressure)
The TX was a danfoss TF2, R12 model, #01 oriface.
I guess my question is I don't even know if the box with that coil could even get to -15C
Is it just a case of a faulty valve, or bad equipment design. How to find out?
In my personal opinion I couldn't see -15C setpoint happening, this is just a fibreglass tub, the bottom of with the tub in the generator/engine room.
The cold plate was only on one side, the fibreglass wass only 5mm think with no other insulation. The condesing unit was a fair bit newer than anything else, so had been relatively replaced recently. The refrigerant/oil smelt rank, like this unit was about to burn out too.
I've got no idea on whether someone just turned the thermostat down on that tub and pronouced it a freezer or not, hence causing these problems. And I, nor the new owner know if that's the case.