APPLICATION GUIDELINES
FRCC.PC.007.B5.02
19
Suggested wiring diagrams logic
Compressor model SH 090 - 105 - 120 - 140 - 161 - 184
ELECTRICAL DATA, CONNECTIONS AND WIRING
By means of the built-in auxiliary contact (23-24)
the by pass function is easily achieved, see wiring
diagram beside.
No heat is generated from the MCI. As the con-
tactor always switches in no-load condition it can
be selected on the basis of the thermal current
(AC-1).
13-14 contact not applicable with MCI 25C.
When the control voltage is applied to A1 - A2,
the MCI soft starter will start the motor, accord-
ing to the settings of the ramp-up time and ini-
tial torque adjustments. When the control volt-
age is switched OFF, the motor will switch off
instantaneously.
MCI with by pass contactor
Input controlled soft start
M
DGT
HP
LPS
180 s
TH
LP
CONTROL CIRCUIT
F1F1
KM
KM
KM
KA KA
A1
A2
A3
KA
KA
KS
KS
KS
L1 L3 L2
Q1
T1
T3
T2
LLSV KS
Wiring diagram with pump-down cycle
KM
L1 L3 L2
Q1
CONTROL CIRCUIT
F1F1
KM KA
KA KS
KS
KS
HP
DGT
TH
180 s
85 52 019 - A
T1
T2
M
T3
KA KA
A1
A2
A3
Wiring diagram without pump-down cycle
LPS
General wiring
information
The wiring diagrams below are examples for a
safe and reliable compressor wiring. In case an al-
ternative wiring logic is chosen, it is imperative to
respect the following rules:
When a safety switch trips, the compressor must
stop immediately and must not re-start until the
tripping condition is back to normal and the safe-
ty switch is closed again. This applies to the LP
safety switch, the HP safety switch, the discharge
gas thermostat and the motor safety thermostat.
In specifi c situations, such as winter start opera-
tion, an eventual LP control for pump-down cy-
cles may be temporarily bypassed to allow the
system to build pressure. But it remains manda-
tory for compressor protection to apply an LP
safety switch. The LP safety switch must never be
bypassed.
Pressure settings for the LP and HP safety switch
and pump-down listed in table from section "Low
pressure".
When ever possible (ie. PLC control), it is recom-
mended to limit the possibilities of compressor
auto restart to less than 3 to 5 times during a peri-
od of 12 hours when caused by motor protection
or LP safety switch tripping. This control must be
managed as a manual reset device.
To Next Page
Loading...
Need help?
General
