Turn the control box downward to access terminal
boards M1 and M2 used for the electrical connections
by removing the two protective covers (see figure 22).
Terminal board M1
Terminal 1-2: Room temperature thermostat "RT"
Note: The M1 bus terminal is 120V. If you are using a
24V thermostat then a 24V relay card, sold as
an accessory, is required.
WARNING
If the room thermostat being used incorporates an anticipator it MUST be wired as shown in Fig. 21 C .
Terminal board M2
Terminals 2-3: are the connections for a zone control pump (see figure 25).
Terminals 4-5: are the connections for the optional SIEMENS QAA73 remote control. These connections do not have any
specific polarity.
Terminals 7-8: are the connections for the optional SIEMENS QAC34 outdoor temperature sensor. Read the instructions
provided with the outdoor temperature sensor to ensure correct installation.
Terminals 9-10: are the connections for thea DHW priority sensor, sold as an accessory (see section 11.2).
Terminal board M3
Terminals 11-12: are the domestic hot water pump connections (see figure 22)
Terminals 13-14: are the central heating pump connections (see figure 22)
The electrical specifications of the pump must be as follows:
120 V AC; 60 Hz; 10 µF; 0.82 A cos f 0.9.
If the specifications of the installed pump are different, a relay must be wired between the boiler control circuit
board and the pump.
Cable guid
To remove
with QAA73
Fig. 23
INSTALLATION AND SERVICING INSTRUCTIONS
11.1 TERMINAL DESCRIPTIONS
Screw
Fig. 22
30
LEGEND:
N.C. - Normally Closed contacts
C
- Common
N.O. - Normally Open contacts
WIRE COLOURS:
M
Brown
N
Black
C
Light blue
R
Red
7110242.02 - en