2. Features and benefits
TCGB0075 rev.0 - 11/2012
46
Complementary heating
Electric heater (as accessory)
For the most low ambient temperature conditions the electric heater will be enabled in order to provide the necessary su-
pplementary heating, but only when the unit is operating in space heating mode.
•
3 steps heater control: The desired heating supplied by heater is determined by the Load factor, which is calculated
by a P+I function ranging from 0 to 100%. Actual heater output will be translated from percentage to a 3 step output
using hysteresis system.
Bi-valent point
A i r t o w a t e r
heat pump
A i r t o w a t e r
heat pump
Heat demand
Air to water heat pump capacity
Heater-SP3Heater-SP2
Heater-SP1
Outdoor ambient
temperature (ºC)
Capacity (kW)
Step
Total input power (kW)
RWH-(4.0-6.0)FS(V)NFE
1
2.0 (*)
2
4.0 (*)
3
6.0 (*)
N O T E
(*): The input power values shown previously are explained as example for water electric heater supplied
for HITACHI as accessory (WEH-6E), with a total input power of 6.0 kW. For water electric heaters of
other total input power, the input power for each step will be different.
•
Electric heater for emergency mode (Optional function): In case of outdoor unit malfunction, the required heating can
be provided by the electric heater.
•
One step heater for 3 phases unbalance (Optional function): For 3 phases units, in order to prevent 3 phases unba-
lance of the installation by electric heater steps, this option will be used to switch the 3 steps at the same time.
Boiler combination
When the unit is not able to provide the necessary heating capacity in low ambient temperature conditions, it will be sto-
pped and the boiler starts to operate providing the necessary heating capacity. The unit should be sized in order to operate
mainly with the air to water heat pump, and boiler will be only activated in low ambient temperature conditions.
Capacity (kW)
Bi-valent point
Boiler
Air to water heat
pump
Heat demand
Air to water heat pump capacity
Heat demand
Outdoor ambient
temperature (ºC)
•
Boiler for emergency mode (Optional function): In case of outdoor unit malfunction, the heating required can be provi-
ded by the boiler.