water cooled condensing unit

[sean1]

hello
got a water cooled condenser in a beer cellar running on r407c but the evaporator keeps icing up towards the bottom.

condenser is a carrier unit
evaporator is a cellarmaster cx 70

the system was sized and matched by the supplier

suction pressure is 4 bar
high side 180psig
water in is 15 celcius
water out 23 celcius
water flow is 1 litre every 10 seconds - supplier states this should be 0.091l/s
the expansion device is a fixed orifice in the condensing unit
there is a noticeable temp differnce in the pipework eighter side if it
where the pipework enters the evap it starts to ice up straight away on the "spiders leg" if you like

i am thinking eighter the orifice partially blocked (but why am i getting 4 bar suction?) or pressure drop in the expansion line?

any comments appreciated:D

[Brian_UK]

Does the unit have the correct refrigerant charge in it?

I think you need to get your gauges matched, it makes life easier ;) Having bar on the LP and psi on the HP, confusing.

[sean1]

refrigerant was weighed in according to manual and double checked with supplier when this fault reported
:D sos the hp is what the supplier said it should be "near"
normally. i work in bar but could not remember what this is in bar:D

[mad fridgie]

Head pressure is to low, your supplier can not give you a flow rate without giving you a start temp. I think you will find that the water in temp is to cold. Reduce flow rate slightly One presumes that there is not a water reg valve on the outdoor unit, if there is just adjust to head pressure rises

[sean1]

supplier based head pressure on +15 celcius - temp of water in (checked and is ) if you add 15 for condensing your in the right ballpark - is my thinking right?:D
there is a regulating valve for the water i did adjust it to 45celcius head pressure but the icing still occured (240psi)

[mad fridgie]

supplier based head pressure on +15 celcius - temp of water in (checked and is ) if you add 15 for condensing your in the right ballpark - is my thinking right?:D
Just reduce flow rate slightly, this will lift the head slightly. You have just over 10% to much flow. This will lift the evap pressure slightly and ice will not form