Electrical connections
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10.6 Combined operation of two heat pumps (cascade connection)
Fig. 37 CANbus overview with two heat pumps
1. Pull the new cabling (according to specified cable) between screw
terminal 31-34 on the PEL board (heat pump 1) and screw terminal
31-34 on the PEL board (heat pump 2).
2. Remove the display cabling in heat pump 2 between BAS and LCD.
Remove the bottom strap to release the cable.
3. Pull out the earth wire from the removed display cabling and re-
connect this to the earth terminal and the earth plate in the front plate
of the heat pump 2.
4. Re-connect CANbus with existing CANbus cabling in heat pump 2 (
Æ
Figure 37).
5. Use cable ties to again fasten cabling in a suitable manner.
6. Re-address BAS (heat pump 2) from A=0 to A=1 (
Æ
Figure 38). Set
termination switch to Term mode on PEL (heat pump 2).
If one wishes to proceed to accessories, this is done from either heat
pump 1 or heat pump 2 - PEL CAN 2 and then set the termination switch
to non-Term mode.
Fig. 38 Addressing heat pumps 1 and 2.
6 720 802 416-19.1I
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2
CAUTION:
Do not mix up the 12V and CAN-BUS
connections!
The processors are destroyed if 12V is connected to the
CAN-BUS.
B
Check that the four cables are connected to the
contacts with the corresponding marking on the
circuit board.
In cascade connection both heat pumps must have the
same output.
PSU and LCD (
Æ
Figure 37) in heat pump 2 are factory
connected, these must be disconnected and are not
used in cascade connection.
The recommended cabling is ELAQBY 2x2x0.5. If other
cables are used besides the recommended ones, the
following must be complied with: screened, twisted pair,
max 30 m, min area 0.5.
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