Sinclair SCMI-01.4 User Manual page 11

Slave unit mode - Operated
Outdoor unit compressor performance is controlled by the SCMI-01.4 module according to
direct voltage 0-10V from an external device. The voltage value corresponds to the desired
compressor performance 0-100%. The On/Off switch must be in the On position and, at the
same time, the control voltage must be higher than 0.5V. Otherwise, if the control voltage
drops below 0.5V, the module switches to the Off state. The slave unit can operate in the
heating mode (Heat) or cooling mode (Cool). In the cooling mode, the outdoor unit heat
exchanger operates as a condenser and transfers the heat to the surrounding environment.
The thermometer T1 measures the temperature of the indoor unit heat exchanger (which
operates as an evaporator), and based on the measured temperature T1, the evaporator
defrosting is controlled. In the heating mode, the outdoor unit heat exchanger operates as
an evaporator and its defrosting is controlled by the outdoor unit circuits. The indoor unit heat
exchanger operates as a condenser and its temperature T1 is used to control the outdoor
unit and to protect against exceeding the condensation temperature of the refrigerant used.
The thermometer T2 measures the temperature in the room. Placing of temperature sensor
T2 depends on The heating (cooling) mode can be set via the input H/C
installation's demands.
and the control module can be activated via the input On/Off. If the input H/C is not
connected, the module operates in the cooling mode; if this input is connected to the
common terminal, the module operates in the heating mode. If the input On/Off is not
connected, the module is switched off; if this input is connected to the common
terminal, the module is switched on. The outdoor unit is controlled via a serial line, which
also supplies its communication circuits. For 1-phase outdoor units, the terminals SC-1 and
SC-2 of the module must be connected to the terminals 1 and 2 of the outdoor unit,
respectively. For 3-phase outdoor units, the terminals are interchanged, so to work properly,
the terminals SC-1 and SC-2 of the module must be connected to the terminals 2 and 1 of
the outdoor unit, respectively.
Fig. 2. SCMI-01.4 control module in the slave mode
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