Mitsubishi Electric ECOV-X37VA Manuel D'installation page 55

12-2. Check items for refrigerant circuit components
Check item
Causes or remedies
Check for any dirt or clogging in the strainer.
Check the strainer.
A heavily clogged strainer can cause the unit to generate ab-
normal sound.
Check that the refrigerant service valve (ball valve) <suc-
tion> is open.
If the valve is left closed, the unit will perform short-cycling
operation, which may result in a poor cooling problem or
compressor damage.
Check that the caps on the check joint and refrigerant ser-
vice valve are securely attached.
If the cap on the suction side of the refrigerant service valve
(ball valve) or a check joint installed before or after this re-
frigerant service valve is off or loose, air can infiltrate and
cause dangerously high pressure.
If the cap or other refrigerant service valve is off or loose, re-
frigerant gas can slowly leak out.
Check that the surface of the compressor, liquid trap, or ac-
cumulator is not rusted.
Check for corrosion at the time of installation and every 5
years thereafter, and record the check results.
• Write down the amount of the charged refrigerant on the rating nameplate with an indelible pen.
Check that the gas cooler fins are not clogged.
A clogged condenser fin can cause the high pressure and
discharge gas temperature to rise dangerously high.
When the refrigerant service valve (three-way valve) <liq-
uid> needs to be closed, check that liquid refrigerant is not
trapped in the pipe section between the two closed valves.
The section of the pipe between the solenoid valve <liquid>
(evaporator side), locally installed valve on the pipe, and re-
frigerant service valve <liquid> can trap liquid refrigerant and
cause the pipe to burst.
Perform a pump down with the refrigerant service valve
(three-way valve) <liquid> closed to remove the liquid refrig-
erant and prevent pipe damage.
Check that the refrigerant service valve (three-way valve)
<injection> is open.
If the valve is left closed, discharge gas temperature will rise
due to insufficient injection.
Check for any clogging in the strainer.
A clogged strainer or dryer will reduce injection speed and
cause the discharge gas temperature to rise.
55
WT09614X03_GB