BoilerNet Interface Controller II
9
V1.00.6
3.3 BoilerNet Connections
The BoilerNet Interface utilizes a 2-wire CAN-bus communications interface between the boilers and the
BIC II. BoilerNet wiring needs to be performed in accordance to published standards, such as ISO 11898
or SAE J2284.
A suitable cable, compliant with standards such as ISO 11898 or SAE J2284 must be used. The wiring
must also be installed in compliance with these standards.
Cerco Cable manufactures cable suitable for CAN-bus use. Cerco AT-HOM 29 #8320, or cable with
equivalent specifications from another cable manufacturer, must be used. The general specifications for
this cable are:
24 AWG shielded twisted pair
9 twists per foot
Capacitance 12.5pF/Ft (cond./cond.)
Resistance 25.5 ohms/1000'
Full specifications and information can be found on the Cerco web site:
http://www.cercocable.com
.
P
lease contact IBC if any additional information is required.
Figure 5
On the boiler's controller board, the "Boiler Net +" is the "CANH" connection, the other terminal is "Boiler
Net –", which is the "CANL" connection. On the BIC II terminal block, the red wire is the "Boiler Net +"
(CANH) connection; the white is the "Boiler Net –" (CANL) connection.
Please note that the BIC II has a 120 ohm CAN-bus terminator built into the controller board, which cannot
be disabled. Therefore, the BIC II must be wired in as either the first or last device in the BoilerNet
communications chain. The termination jumper (JA02) needs to be removed from all the boiler controller
boards with the exception of the first or last boiler of the BoilerNet chain. Please refer to
Figure 6
below
for an example diagram.