[jappell]

I have never worked on one and got a call only to find the compressor has open windings.
Tommorrow the new one goes in and I'd like
to know what I'm not seeing inside the 6 ton tank.ie the eval coil.
Just a static coil? what pressures am I looking for?
low temp R404 copeland
It's been working since 07 so this is going to be a new learning experience.
Hoping it's painless:grin2:

 

[mspanky]

It's been many years since I've worked on one, but they always had 2 t-stats. One for the small condensing unit and one for heaters to bring the tank pressure back up if needed. The evap is just a static coil, like you said. Make sure the superheat on the condensing unit is good (10-15*F). The plant managers always set the t-stat settings themselves so I don't remember the numbers off hand, but I would think are less than 50*F due to pressure limitations on the CO2 vessel.

 

[jappell]

Thanks, right now that tank is sitting in the florida sun just oozing co2 thru the pressure relieves. So they need to be <50F to stop dumping.........good to know!

 

[mspanky]

The pressure relief valves, of course, will dictate what pressure you need to maintain. Find yourself a p/t chart for CO2 and go from there, but room temperature will be above 800psi.

 

[crazzycajun]

:.02:Some of the ones i worked on dont use temp to cycle the the cond unit. They use tank pressure ie pressure switch to keep the co2 in my cases around 350#

 

[jappell]

Waiting still, 460 volt will be in tomorrow.
it does seem to run off tank pressure, 2 cap tubes running to control box from tank. Their hooked up to a stat that de-energizes the LLSV. Will let You know how it works out,
Goodnight.

 

[WT70]

This one brings back memories. I worked on a refrigeration system for a 1000 lb CO2 storage tank many years ago. Valve plates bad in the compressor. Like crazycajun, this one ran off a tank pressure control. The control stuck closed, tank was low on product, evap ended up flooding compressor. They didn't realize they had a problem until they had tank refilled.

Anyway, one of the hottest days of the summer and I'm sitting in the doghouse changing the valve plate. There were 2 pressure reliefs on the tank. A slow bleed to help keep tank cool if refrigeration went out, and an emergency pop off just in case. I did not realize the pop off was right above my head. As I was sitting there cleaning gaskets off the compressor body, the emergency pop off decided to let go. Needless to say, I thought I was going to have to go home and change my underwear.

Gave me an early lesson on "pay attention" to your surroundings lol.

Sent from my SCH-I605 using Tapatalk

 

[jappell]

So united finally got Us the pump yesterday, nice install. Started up fine, at this point only an eight of a tank left.
Tank got filled today and it was cycled off at 300 psi. It is controlled by tank pressure, ci 305, co 295 Perfect:cheers:

 

[itimalupet]

This one brings back memories. I worked on a refrigeration system for a 1000 lb CO2 storage tank many years ago. Valve plates bad in the compressor. Like crazycajun, this one ran off a tank pressure control. The control stuck closed, tank was low on product, evap ended up flooding compressor. They didn't realize they had a problem until they had tank refilled.

Anyway, one of the hottest days of the summer and I'm sitting in the doghouse changing the valve plate. There were 2 pressure reliefs on the tank. A slow bleed to help keep tank cool if refrigeration went out, and an emergency pop off just in case. I did not realize the pop off was right above my head. As I was sitting there cleaning gaskets off the compressor body, the emergency pop off decided to let go. Needless to say, I thought I was going to have to go home and change my underwear.

Gave me an early lesson on "pay attention" to your surroundings lol.

Sent from my SCH-I605 using Tapatalk

I have the same issue, the evaporator keeps flooding the compressor and the C02 pressure does not drop down. Where is this valve plate located? what does it actual purpose?

 

[GenesisRefrig]

I work on these all the time. Mine have been controlled by tank pressure. Cut in at 310psi, cut out at 295psi. The refrigeration system is pump down with a solenoid valve. There is a high and low pressure control on the refrig side. Pretty basic.

 

[itimalupet]

I have an issue with regards to this one. The evaporator keeps flooding the compressor seems there is no heat exchange inside the evaporator and the CO2 tank pressure does not go down. What should be done?

 

[GenesisRefrig]

I have an issue with regards to this one. The evaporator keeps flooding the compressor seems there is no heat exchange inside the evaporator and the CO2 tank pressure does not go down. What should be done?

Adjust the expansion valve to get higher superheat.

 

[itimalupet]

Thank you for your time.
But no, there is no issue with the TXV and the air cooled condensing unit. It seems the liquid refrigerant does not evaporate in the evaporator coil inside the tank. I tried adjusting TXV opening every 30mins until max opening still no help.

 

[itimalupet]

I want to know if there is some part of CO2 tank that I must check? since the co2 tank is old

 

[GenesisRefrig]

Thank you for your time.
But no, there is no issue with the TXV and the air cooled condensing unit. It seems the liquid refrigerant does not evaporate in the evaporator coil inside the tank. I tried adjusting TXV opening every 30mins until max opening still no help.

You’re going the wrong direction. If you’re flooding back, you want to close the valve, not open it.

 

[itimalupet]

Hi,

Yes thanks, I do it either way but still no help.

 

[pecmsg]

How much are you urning and how long are you waiting? Whats the SH at the compressor?

Find the mid-point on the adjustment and close it 1/2 turn, wait 15 minutes before measuring super heat.

 

[itimalupet]

I was wondering what is the state of the CO2 in the tank before and after cooling?

Is it always in gas state? or it condenses as it cooled down by the evaporator inside the CO2 tank

 

[pecmsg]

Liquid!

Have you reset the valve to mid point and checked SH?

 

[pecmsg]

Do you have any technical information?