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• Scroll Condensing Unit • JEHSCU
21
• Scroll Condensing Unit • JEHSCU
9
Installation & Commissioning
Important Note
There must be no more than 10 compressor starts per hour.
A
higher number reduces the service li
f
e o
f
the compressor. I
f
necessary,
use an anti-short-cycle timer in the control circuit. Minimum a 3 minute runtime a
f
ter each start o
f
compressor and a 3 minute idle time a
f
ter
each stop are recommended. Only during the pump do
w
n cycle may the compressor run
f
or much shorter intervals.
Fan speed controller setting
The
f
an speed controller controls the speed o
f
the condenser's
f
an.
It
k
eeps the condensing pressure at a steady level by changing the speed o
f
the
f
an according to the required condensing pressure.
Factory setting is 19 barg and the operation during lo
w
pressure is "cut o
ff
" mode.
Recommend setting
f
or range setting pointer/ range adjusting scre
w
as table belo
w
:
Commissioning of the Condensing Unit
Please ma
k
e sure that all manual service valves are
f
ully open
w
hen starting the system
f
or the
f
irst time. This includes external shut o
ff
valves as
w
ell
as liquid receiver valve in the unit.
Compressor electrical wiring
Important Note
Compressor
w
iring
f
or 3 phases modals must be controlled. Supply phase sequence
L1, L2 and L3
w
ill a
ff
ect the compressor rotating direction and damage the compressor.
Service technician should be present at initial start- up to veri
f
y that the supply po
w
er
is properly phased and that compressor is rotating in the correct direction.
Veri
f
ication o
f
proper rotation direction is made by observing that suction pressure drops and discharge pressure rises
w
hen the compressor is
energized. Reverse rotation o
f
a scroll compressor also results in substantially reduced current dra
w
. Suction temperature
w
ill be high, discharge
temperature
w
ill be lo
w
and the compressor may be abnormal noisy.
Refri
g
er
a
nt R404A R134
a
S
ettin
g
(b
a
r
g
)
19 10
Clockwise: Incre
a
se
pressure set point
Anticlockwise:
Decre
a
se
pressure set point
360
0
= 1 turn
Approx. 1.5 b
a
r
g
EE
D
E
N
1
3
-
780A
_
Scro
ll
Condensing
U
nits
- JEH
SC
U.p
d
f 2
3
30
/
0
4/2
0
1
3
16:11:11