30
FIG. 39
FIG. 40
13. Electrical Connections (continued)
13.2 Connecting Zone Valves (MINIMA HE System only)
The boiler can be connected to a central heating system that uses
two zone valves to allow connection to an indirect storage cylinder.
There are two wiring diagrams shown, one for the connection to an
U
nvented Cylinder (Diagram. A, page 30) and one for connection
to an open vented cylinder (Diagram B, page 31).
In both cases the boiler connection is shown as
R
OOM
, which
r
elates to the terminal on the PCB for external controls (see
1
2F
IG.
32, page 26
).
When connecting the boiler to an external cylinder do not run 240V
cables and the cables for the R
OOM
terminal (12 Fig. 32, page 26)
together, use separate cables to prevent induced voltage on the
l
ow voltage switching circuit.
NOTE:THEUSEOFA‘Y’ PLAN SYSTEM IS NOT POSSIBLE WITH THE
MINIMA HE SYSTEM BOILER DUE TO THE LOW VOLTAGE SWITCHING OF
THE APPLIANCE
.
* IM
PORTANT
!!
EN
SURE THAT A BALANCING VALVE IS FITTED ON THE
CYLINDER R
ETURN
AND BALANCED CORRECTLY AT
C
OMMISSIONING STAGE
.
*