Sinclair SDV 6 Service Manual page 53

6.8 Controlling the Condensate Water Pump and Water Level Switch
1) When the IDU is powered on the first time, the water pump is forced to operate for 5 minutes.
2) When the IDU and ODU are in cooling, dehumidification and self-cleaning mode, the water pump starts immediately
and operates continuously. After this mode is stopped (stop or mode switch), the water pump turns off five minutes
later.
3) If the water level rises, causing the water level switch to be disconnected, the condensate water pump immediately
starts and operates. Five minutes later, if the water level drops to lower than the alarm level, the system restores
operation based on the originally set mode. Otherwise, the IDU and water pump stop operating, and a water level
alarm is reported. When the water level switch is connected again, the protection is released, and the system restores
operation based on the mode that was originally set.
Note:
This function is reserved for the unit models without drainage pumps and water level switches and it is disabled by default.
6.9 Anti-freeze Control
The IDU will close Electronic expansion valve, and the wind shift into speed 1.
Condition:
A) Entry conditions: Coil temperature ≤A continuous T1 or coil temperature ≤B continuous T2, and in any mode of
forced cooling, cooling, dehumidification, self-cleaning(Except for the second stage);
B) Exit condition: coil temperature ≥C continuous T3, and not in any mode of forced cooling, cooling,
dehumidification, or at the second stage of self-cleaning mode;
6.10 Alarm control
Both IDU'S main control board and 1# Expansion board (Optional) have ALARM port, and can be used simultaneously.

Setting positive or negative logic
①Port on IDU'S main control board
The positive and negative logic of the IDU main control board is set by the wired controller or central controller. (N40)
②Port on 1# Expansion board (Optional)
The positive and negative logic of the 1# expansion board is set by the S2-1/S2-2/S2-3 DIP switch on the 1# expansion
board.

Remote on/off port setting status and its corresponding function
Outdoor unit Set
Positive logic
negative logic
50
Port status
Set to
The port is
connected
(Default)
Set to The port is
disconnected
Functional interpretation
outputs alarm signals
outputs alarm signals