• Scroll Condensing Unit • JEHSCU
23
• Scroll Condensing Unit • JEHSCU
11
Checkpoints
•
Ensure the high lo
w
pressure controls are con
f
igured properly.
•
Ensure cran
k
case heater is energized minimum 12 hours prior to start up and permanently energized.
•
Chec
k
the re
f
rigerant is correct
f
or intended use.
•
Chec
k
all electrical connections.
•
Chec
k
all electrical termination and circuits are correct.
•
Chec
k
compressor oil level via compressor sight glass, the oil level should not be lo
w
er than quarter o
f
sight glass.
•
Ensure
f
an motor and
f
an blades are installed properly.
•
Chec
k
the TXV capacity sizing based on indoor unit capacity. Chec
k
TXV applicable re
f
rigerant. Chec
k
position and condition o
f
the sensing bulb
f
ixing
•
Observed the system pressures during the charging and initial operation process.
•
Ensure that suction pressure
w
ill decrease, discharge pressure
w
ill increase. No abnormal noise
f
rom the compressor.
•
Continue to charge the system until sight glass is clear. Ma
k
e sure that high pressure is > 14 barg
f
or R404
A
and > 8 barg
f
or R134a
w
hen doing
this charge adjustment operation. Continuous
f
lo
w
o
f
clear re
f
rigerant through the sight glass,
w
ith perhaps an occasional bubble at very high
temperature indicates the re
f
rigerant is at optimum.
•
Chec
k
the compressor's discharge and suction pressure, ensure it's
w
ithin operating range. Discharge temperature should be
w
ithin 50 to 90 °C
and pressure should be around 15 to 2
6
barg (
f
or system charged
w
ith R404
A
) and 8 to 1
6
barg (
f
or system charged
w
ith R134a).
•
Chec
k
the current o
f
condensing unit and ensure it belo
w
the isolator setting value.
•
Chec
k
condenser
f
an, ensure
w
arm air blo
w
ing o
ff
the condenser coil.
•
Chec
k
evaporator blo
w
er, ensure it's discharging cool air.
•
Chec
k
suction superheat and adjust expansion valve to prevent liquid
f
lood bac
k
to the compressor. Recommended 5 to 20 K o
f
suction superheat.
•
Do not leave the system unattended until the system has reached its normal operating condition and the oil charge has properly adjusted itsel
f
to
maintain the proper level in the sight glass.
•
Chec
k
periodically the compressor per
f
ormance and all the moving components during the
f
irst day o
f
operation.
•
Chec
k
the liquid line sight glass and expansion valve operation. I
f
there is an indication that the system is lo
w
on re
f
rigerant, thoroughly chec
k
the
system
f
or lea
k
s be
f
ore adding re
f
rigerant.
EE
D
E
N
1
3
-
780A
_
Scro
ll
Condensing
U
nits
- JEH
SC
U.p
d
f 25
30
/
0
4/2
0
1
3
16:11:11