10
General
In Rego 800 the different circuit boards are connected by a communica-
tions cable, CANbus. CAN is an abbreviation of Controller Area Network
and is a two wire system for communication between the microprocessor
based modules/circuit boards. These are connected in series.
The heat pump has one circuit board (IOB circuit board), other circuit
boards are in the electric boiler. A power guard, which also connects to the
CANbus, is available as an accessory.
Cable ELAQBY 2x2x0.6A is suitable cable for external laying (con-
nection between the circuit boards). The cable must be twisted pair and
screened. The screen must only be earthed at one end and to the chassis
(not to the circuit board). Maximum cable length is 20 m.
CANbus cables must not be laid alongside power cables. They may be laid
alongside sensor cables.
In the connection area of the heat pump and the electric boiler the external
CANbus cable must be laid so that it does not come into contact high
current connections (230/400V).
The connection between the circuit boards is by four wires since the
12V-supply between the circuit boards must also be connected. The circuit
boards have markings for both the 12V and CANbus connections.
Warning
Do not mix up the 12V and CAN-
bus connections! If 12V (or other
incorrect voltage) is supplied to the
CANbus contacts the processors in the
CANbus are destroyed. Check, there-
fore, that the four cables are connected
to the contacts with the corresponding
marking on the circuit boards in the
electric boiler and the heat pump.
Switch S1
The switch is used to mark the start and end of a CANbus loop. This
means that the display circuit board in the electric boiler (marked CPU on
the wiring diagram) and the IOB circuit board in the heat pump must be
terminated using S1, which must be in position Term. If a power guard is
used this circuit board must be terminated instead of the CPU circuit board
in the electric boiler. Ensure that the correct circuit boards are terminated
and that all other switches are in the opposite position.
CANbus
Warning
The CANbus cable must be screened
and laid separately from the power
cable to prevent interference in the
CANbus communication.
Warning
Handle the circuit boards with great
care. They are sensitive to ESD (Elec-
trostatic discharge), which can cause
faults in electronic components.
Screen