User Guide
Table Of Contents
- Compressor model designation
- Danfoss scroll compression principle
- Features
- Technical specifications
- Dimensions
- Electrical data, connections and wiring
- Approval and certifications
- Operating conditions
- System design recommendations
- Specific application recommendations
- Sound and vibration management
- Installation
- Compressor handling and storage
- Compressor mounting
- Compressor holding charge
- System cleanliness
- Tubing
- Brazing and soldering
- System pressure test
- Leak detection
- Vacuum evacuation and moisture removal
- Filter driers
- Refrigerant charging
- Insulation resistance and dielectric strength
- Commissioning
- Oil level checking and top-up
- Ordering information & packaging
- Accessories
Application guidelines
20 AB237986441643en-US0701
MCI with bypass contactor
General wiring information
Input controlled soft start
By means of the built-in auxiliary contact (23-24)
the bypass function is easily achieved, see wiring
diagram below.
No heat is generated from the MCI. As the
contactor 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
The wiring diagrams below are examples for a
safe and reliable compressor wiring. In case an
alternative wiring logic is chosen, it's 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 safety 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 specic situations, such as winter start
operation, an eventual LP control for pump-
down cycles may be temporarily bypassed to
allow the system to build pressure. But it remains
mandatory 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 are indicated section “Operating
conditions”.
When ever possible (ie. PLC control), it is
recommended to limit the possibilities of
compressor auto restart to less than 3 to 5 times
during a period of 12 hours when caused by
motor protection or LP safety switch tripping.
This control must be managed as a manual reset
device.
When the control voltage is applied to A1 - A2,
the MCI soft starter will start the motor, according
to the settings of the ramp-up time and initial
torque adjustments. When the control voltage
is switched OFF, the motor will switch o
instantaneously.
Compressor models SM / SZ 084 - 090 - 100 - 110 - 112 - 120 - 124 - 147 - 148 - 161
Suggested wiring diagrams logic
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
Electrical data, connections and wiring