Unit Cooler Ice Up

Hi, Everyone. I faced some problems of my project.
I installed a set of Compressor and Condenser c/w 2 units of different model of unit coolers for 2 units of coldroom. Below show the model of items that installed:

Compressor: Bitzer 4EC-6.2Y-BJ Semi Hermetic Compressor
Eden EFGP 0343.51 RB G4 Condenser 34.3Kw
Eden FEME 0450 G4 Unit Cooler 4.50Kw @ 6KTD c/w 3x300mm fan set (Temperature Require -2'c)
Eden FEM 0492 G4 Unit Cooler 4.92 Kw @ 8KTD c/w 1x300mm fan set (Temperature Require 3'c)

The problems that i faced are when the Coldroom A reached -2'c, Coldroom B's unit cooler will ice up.
May I know what's wrong of the unit cooler happened? Can any one could help and assist to solve this situation.

Thanks and Best Regards.

To reach your target set points of -2C and +3C, both units will need to evaporate below freezing, therefore, it is normal for the indoor units to ice up. You should install a defrost system to both units.

How are you controlling the temperature in the +3C space? do you have an EPR or LLSV fitted?

Hi, Thanks for your reply.
The both systems installed defrost system, it work normal 12 months previous and this problem occur this month.
In the pass 12 months, defrost every 6 hours but now have to defrost every 2 hours.

is it 2 separate systems?
do you have ice on suction side of comp.( check expansion valve).
what is the definitional temp. on both units.?
check evaporates air flows.
are your doors sealed ?

Hi hong
I would be checking the door seals. Sounds like there is a lot of outside air getting in and this would be fairly humid I would expect given where you are.
A bit more information about the system components would also be helpful (see Franks post).
Have you checked the charge, are the LL driers blocked, is the condenser blocked.
Paul

hi , can I take it you have liquid solenoids on both systems ? if you have, then you could have liquid line no1 going to cond, unit no 2 so you would end up with one unit trying to pump down both systems into one unit?= sedgy