Daikin VRV IV+ Service Manual page 404

6 | Technical data
Service manual
404
Component functionalities
Symbol Component
M1C Compressor
M2C Compressor
M1F Fan motor
M2F Fan motor
Y1E Electronic
expansion valve
(upper heat
exchanger)
Y2E Electronic
expansion valve
(sub-cool)
Y3E Electronic
expansion valve
(lower heat
exchanger)
Y4E Electronic
expansion valve
(receiver gas
purge)
Y5E Electronic
expansion valve
(liquid cooling)
Y1S 4‑way valve
Y2S Solenoid valve
(liquid pipe)
Y3S 4‑way valve (high
pressure/low
pressure gas pipe)
Y4S 4‑way valve (lower
heat exchanger)
Y5S 4‑way valve (upper
heat exchanger)
Y11S Solenoid Valve (oil
separator 1 oil
return)
Major function
Inverter driven compressor operates in multi-
steps according to T for cooling and T
e
heating.
Inverter driven compressor operates in multi-
steps according to T for cooling and T
e
heating.
When outdoor coil is used as condenser, the
fan operation is controlled by T
mode the fan operates in full steps.
When outdoor coil is used as condenser, the
fan operation is controlled by T
mode the fan operates in full steps.
While in heating operation, PI (proportional
integral) control is applied to keep the outlet
superheat degree of upper heat exchanger
constant.
PI (proportional integral) control to keep outlet
superheat on sub‑cool heat exchanger.
While in heating operation, PI (proportional
integral) control is applied to keep the outlet
superheat degree of lower heat exchanger
constant.
Used to collect refrigerant to the receiver.
Controls the amount of refrigerant flowing
through the cooling plate that cools PCB.
Switches operation mode between cooling and
heating.
Liquid shut-off valve.
This is used to switch dual pressure gas pipe to
high pressure or low pressure.
Used to switch heat exchanger as evaporator
or condenser.
Used to switch heat exchanger as evaporator
or condenser.
Controls amount of oil return from oil
separator to compressor.
for
c
for
c
, in heating
c
, in heating
c
REYQ8~20+REMQ5U7Y1B
VRV IV+ Heat Recovery
ESIE18-15B – 2020.05