Service manual

Control Specification SiBE05-722_C
40 Function and Control
3.3 Controls at Mode Changing / Start-up
3.3.1 Preheating Control
Outline The inverter operation in open phase starts with the conditions of the preheating command from
the indoor unit, the outdoor temperature, and the discharge pipe temperature.
Detail

RK(X)S25/35E2V1B, RK(X)S25/35G2V1B
ON Condition

When the discharge pipe temperature is below 10°C, the inverter operation in open phase
starts.
OFF Condition

When the discharge pipe temperature is higher than 12°C, the inverter operation in open
phase stops.

RK(X)S25/35G2V1B9, RXS25/35J2V1B, RXS25K3V1B, RXS35K2V1B
Outdoor temperature ≥ A°C → Control I
Outdoor temperature < A°C → Control II
Control I

ON condition
Discharge pipe temperature < B°C

OFF condition
Discharge pipe temperature > C°C
Radiation fin temperature ≥ 90°C
Control II

ON condition
Discharge pipe temperature < D°C

OFF condition
Discharge pipe temperature > E°C
Radiation fin temperature ≥ 90°C
3.3.2 Four Way Valve Switching
Outline In heating operation, current is conducted, and in cooling operation and defrost control, current
is not conducted. In order to eliminate the switching sound as the four way valve coil switches
from ON to OFF when the heating is stopped, the OFF delay switch of the four way valve is
carried out.
Detail OFF delay switch of four way valve:
The four way valve coil is energized for 160 seconds after the operation is stopped.
A (°C) B (°C) C (°C) D (°C) E (°C)
RK(X)S25/35G2V1B9
RXS25/35J2V1B
710122022
RXS25K3V1B
RXS35K2V1B
–2.5 0 2 10 12