Just repaired a leak on 1 circuit on an airedale closed control unit charged with 15kg of r407c to 10k of subcooling and is now running with 7k of superheat, air on 20 degrees c and air off 5 degrees c, unit has a tev and has 2 separate circuits with 2 x 15kw coils. The compressors are copeland scrolls with 2 remote condensers as the compressors are in the indoor unit.
Here is the problem.
Upon start up the head pressure before the tev struggles before the compressor has sucked the gas out of the evaporator causing the lp alarm to trigger but only when the temp drops below 0 outside when it is above 0 it goes down to about 1.5 bar before stabilising after about 30 seconds then the system runs perfectly.
What solution could be done,
Pipe run is 40 metres so 80 metres of discharge line in total.
Can the compressor be changed to 2 stage compressor ?
Electronic tev ?
Move the condenser nearer to indoor ?
Any thoughts
Thanks in advance.
MATT.