Motorized Valve Pi Control - Daikin VRV R-407C PLUS Series Service Manual

Outline of Control (Outdoor Unit)
3.2

Motorized Valve PI Control

Controls the motorized valves (EV1, EV2, EV3) to maintain the outlet superheated degree (SH) of the
outdoor heat exchanger (evaporator) at constant during heating operation.
SH = Th6 – Te
Te: Low pressure equivalent saturation temperature (˚C)
Th6: Accumulator outlet temperature (˚C)
Superheated degree target value (SHS)
DSHi: Inverter discharge pipe superheat
44
Initial value at the start of motorized valve control: SHS = 5 ˚C
When Th6 – Te < 5: SHS (new) = SHS (current) + 1
However, when Th6 – Te < 5 and DSHi < 30: SHS = 7 ˚C (fixed)
When Th6 – Te > 10: SHS (new) = SHS (current) – 1
SiE 00-07
Function R-407C PLUS Series