Hitachi PC-ARF Technical Catalogue page 165

4 Individual remote controls
PC-ART
Step
No.
12 Indoor unit microcomputer input/output.
13 Outdoor unit microcomputer input/output.
PCB relay
YH2
Y52H
Y211
Y212
Y52C1
Y52C2
Y20A
Y20B
Symbols with the letter Y are relays on the indoor/outdoor unit PCB plate.
149
TCGB0106 rev.0 - 12/2014
Microcomputer input/output indication
Heat Thermostat on
Cold Thermostat on
Dark
Y52C2
Y212
Dark
Part name
Relay for drain pump (MD) and/or dew heater (EHW).
Relay for electric heater (CEH).
4-way valve relay.
Compressor relay.
Solenoid valve relay.
Alarm
Operation
YH2
Y52H
Y211
Y52C1
Y20B
Y20A
Fan operating
C1 Z
C2 -
4