Relay Operation; Compressor Contactor; Solid State Relay - Mitsubishi Electric MSH09TW Service Manual

RELAY OPERATION

MSH09TW MSH09TW -
MSH12TN MSH12TN -
MSH15TN MSH15TN -
MSH17TN MSH17TN -

1. COMPRESSOR CONTACTOR

• EACH MODE
MODE
COOL &
COOL mode
of I FEEL
CONTROL
DRY &
DRY mode
of I FEEL
CONTROL
HEAT &
HEAT mode
of I FEEL
CONTROL
NOTE : Once the compressor is OFF, "3-minute time delay circuit" works at next start-up.
• COIL FROST PREVENTION
MODE
COOL &
COOL mode
of I FEEL
CONTROL
DRY &
DRY mode
of I FEEL
CONTROL
2. SOLID STATE RELAY (INDOOR FAN MOTOR RELAY)
MSH12TN MSH15TN MSH17TN MSH12TN -
Indoor fan speed
High
Med.
Low
Very Low
OFF
U1
U1
U1
U1
52C CONTACTOR
THERMOSTAT
ON
OFF
OFF for 2 min. after
unit starts operation.
ON
Repeat of 8 min. ON/3min.
OFF operation or 2 min.
ON/3 min. OFF operation
Repeat of 4 min. OFF/
OFF
1 min. ON operation
ON
OFF
52C CONTACTOR
THERMOSTAT
OFF for 5 min. After
that, OFF is pro-
longed until indoor
ON
coil thermistor reads
termination temper-
ature.
MSH15TN -
U1
Relay turning ON
SR144
SR143
SR142
SR141
All fan relays are OFF.
ON
AUTO or set speed
OFF
AUTO or set speed
AUTO or set speed links with 52C
contactor.
AUTO or set speed
ON
OFF OFF or Very Low speed
AUTO or set speed
AUTO or set speed
<MSH12/15/17>
Low speed when coil frost prevention
starts while COMPRESSOR OFF
MSH17TN -
U1 U1
100
INDOOR FAN SPEED
INDOOR FAN SPEED