Service Manual

SiUS281811E Outline of Control (Indoor Unit)
Part 4 Functions and Control 109
Note(s)
6.10.2 Heat Pump Lockout Control
For heating operation, users can select to use electric heater. For this, signals are sent using ABC
terminal of outdoor unit PCB.
When the hot-water heating signal is received from the outdoor unit PCB, heating operation is
performed only with the electric heater as manual backup operation. The ON/OFF conditions for
the electric heater are shown below.
Thermostat OFF/Operation OFF
ENTRY/
5 minutes timer starts.
• Condition A
• Time up (∗2)
&
H/P Heating: Not in operation
Heater 1: ON
Heater 2: OFF
Fan: ON
Entry/
5 minutes timer starts.
&
OR
• Thermostat step 2: OFF
H/P Heating: Not in operation
Heater 1: ON
Heater 2: ON
(OFF for single heater)
Fan: ON
• Electric heater capacity setting:
Setting not available
• Thermostat step 2: ON
• Time up
• Electric heater capacity
setting: Setting available
Not
Condition A
Not
Condition A
&
Condition A
OR
Condition B: Heater backup prohibiting conditions (∗1)
• Heating or automatic heating mode
• Thermostat step 1: ON
• No fan motor system error
•
Hot-water heater: 1 (ON)
• Heater backup prohibiting conditions (∗1) not met
(Not Condition B)
• Indoor unit error (Abnormal stop)
• Indoor unit error (Remote controller thermistor error)
• Indoor unit error (Remote sensor error)
•
Electric heater capacity setting: 01 (No heater kit)
1: The heater backup prohibiting conditions are prioritized. Even when the heater ON
conditions are met, the heater is turned OFF when the prohibiting conditions are met.
2: When the remote controller is ON, Time-up will be set to the initial value.