Auxiliary Electric Heaters - United Technologies Carrier 30RQM 160 Installation, Operation And Maintenance Instructions

7 - WATER CONNECTIONS
Example 3: operation in series - control on water
outlet for a combination of units
1
Legend
B
Master unit
C
Slave unit
Electrical boxes for Master and Slave units
Water inlet
Water outlet
Water pumps for each unit (included in units with hydraulic module)
T Additional sensors for the control of the leaving water temperature to be
connected on channel 1 of the slave boards of each Master and Slave unit
CCN communication bus
Connection of two additional sensors
Non-return valve

7.7 - Auxiliary electric heaters

To compensate for the reduction in the heat pump's output at low ambient temperatures, which changes significantly as shown in the
graph below, it is possible to install auxiliary electric heaters on the unit's water outlet.
These heaters (not supplied) can be controlled via option 156.
Four outputs are available to control the switches (not supplied) on the auxiliary electric heaters, allowing gradual compensation of
the heat pump output reduction.
These outputs are configurable to allow for two, three or four stages as required. The last stage is only activated in case of shut-down
due to a fault on the heat pump (emergency).
In the graph below, the power of the four heaters equals the capacity of the heat pump at an outdoor air temperature of 7°C.
120
100
80
2
60
40
20
0
-15
Operating range for which the heat pump output is less than the building thermal
load
Operating range for which the heat pump output is greater than the building
thermal load
1 Stage 1
2 Stage 2
3 Stage 3
4 Stage 4 (safety)
A Variation of the heat pump output with air temperature
B Building thermal load
C Point of equilibrium between the heat pump output and the building thermal load
Example of additional electric heaters
1
1
2
1
2
3
C
4
-10 -5 0
A
B
5 10 15
33