
18
-
Installation & Servicing
INSTALLATION
19 INTERNAL WIRING CONT'D
Detail of electrical connections on the 'CVI' control boards mounted directly onto the gas valves.
12
10
8
6
4
2
11
9
7
5
3
1
10K
5V
+
-
L
N
E. ACC.
E. RIV.
PR
LB
TL
PV
E. ACC.Ignition electrode
E. RIV Ionisation electrode
PR
Rest button (on fascia panel)
LB
Lockout warning light (within reset button)
TL
High limit thermostat (local)
PV
Fan air pressure switch
L - N
Supply terminals on CVI
1-2
Ionisation signal to MBD
WARNING!
To disconnect the
ignition lead from the
CVI hold directly on
the terminal (fast-on)
and not on the lead.
ima 5789
20 CONTROL BOARD LOCATIONS
The MBD is the main control board, which determines how
many modules should fire, the rate required and the flow
temperature required. It can communicate directly with the
CVI controls of 2 modules.
The AM-5 board is a supplementary board used with boilers
containing more than 2 modules. It provides the interface
between the MBD and an additional 2 modules per AM-5
board. See Frame 22 for guidance on how the AM-5 dip
switches should be configured.
MBD
AM-5
AM-4
7 modules
5 and 6 modules
3 and 4 modules
2 modules
ima 5787
The AM-4 board provides several interface functions. It
provides the functionality required for controlling the boiler with
the BMS 0-10V system. This board controls operation of a
DHW pump or valve. The output in DHW mode can also be
limited by this board, see Frame 21.
The CVI boards are attached directly to the gas valves of the
modules they control. When instructed by the MBD they provide
the safe ignition and flame supervision of their modules.
INST
ALLA
TION