Daikin Altherma HT Service Manual

ESIE09-08B External Backup Heater Kit
Appendix 251
7.5 External Backup Heater Control
Normal operation
(*): approximate value (depends on operation conditions (e.g. dT, HP indoor unit))
Step 0 -> Step 1
&
 20 minutes compressor operation
 Compressor runs on high frequency
 Pump speed > ~2500 rpm (with E-03 set to default 1)
 LWT > ~ LWT setpoint - 8 (*)
 LWT < ~ LWT setpoint - 4 (*)
 If controller room thermostat function: RT<RT setpoint - 2 (normal heat load)
Step 1 / 2 -> Step 0
or
 Q2L = OFF
 DHW operation
 LWT > LWT setpoint + 2
 If room thermostat function: RT > RT setpoint
Step 1 -> Step 0
 LWT > LWT setpoint
Step 1 -> Step 2
&
 TM2 up
 LWT < ~ LWT setpoint - 6 (*)
 RWT < ~ LWT setpoint - 10 (*)
Step 2 -> Step 1
or
 LWT > ~ LWT setpoint - 2,5 (*)
 RWT > ~ LWT setpoint - 6 (*)
Step 0 -> Step 2
&
 20 minutes compressor operation
 Compressor runs on high frequency
 Pump speed > ~2500 rpm (with E-03 set to default 1)
 LWT < ~ LWT setpoint - 8 (*)
NORMAL OPERATION
(BUH assistance)
Step 0
(no BUH operation)
Step 1
Step 2
TM
1
TM
1
TM
2
TM
2
Note
 Timer during normal operation
The TM* indicate timers, these start counting down if they
are crossed when going from one step over to another
step.
TM1: 5 minutes
TM2: 10 minutes
 BUH operation after defrost if already active before
Timer: 10 minutes
Compressor operation: 5 minutes & high frequency

Daikin Altherma HT Specifications

General

Type	Air-to-water heat pump
Refrigerant	R-410A
Water Outlet Temperature	Up to 80°C
Operating Temperature Range	-20°C to 35°C
Power Supply	3-phase, 400V
Energy Efficiency Class (Heating)	A++