27
9.0 Installation
© Baxi Heating UK Ltd 2012
b
br
b
bk
g/y
1
N
L
2
N
N
L
Room ‘Stat
Fused Spur
230V
Fig. 36
Fig. 34
b
br
b
bk
g/y
1
N
L
Frost Thermostat
External Clock
2
Pipe Thermostat
N
N
L
Room ‘Stat
Fused Spur
230V
230V
NOTE:
The 230V switched signal for external controls
(Frost Stat - Room Stat - Timer) must always be taken
from terminal 2 at the boiler. Live, Neutral and Earth to
power these controls must be taken from the Fused Spur.
Fig. 35
9.7
Making The Electrical Connections
1. See Section 7.5 for details of the electrical supply. Undo
the securing screws and lift the case front panel off.
2. Disengage the securing tab and hinge the control box
downwards. Undo the terminal block cover securing screw
and remove the cover (Fig. 34).
3. Slacken the gland nut in the left of the boiler lower panel
and pass the mains cable through it. Remove the grommet
adjacent to the gland nut, pierce the diaphragm and insert
the cable from the external control system.
4. Leave sufficient slack in the cables to allow the Control
Box to be hinged fully open. Tighten the gland nut and refit
the grommet.
5. Connect the Earth, Permanent Live and Neutral wires to
the terminal strip.
NOTE:
Both the Permanent Live and Neutral
connections are fused.
6. Refer to the instructions supplied with the external
control(s).
IMPORTANT:
Any thermostat
MUST
be suitable for
230V switching.
7. Remove the link between terminals 1 & 2. The 230V
supply at terminal 2 must be connected to the thermostat.
The switched output from the thermostat must be
connected to terminal 1. (Figs. 35 & 36). If the room
thermostat being used incorporates an anticipator it MUST
be wired as shown in Figs. 35 & 36.
NOTE:
When only Low Voltage controls are being used
(connected to Terminal M2) it is necessary to remove
the link wire !
8. Replace the terminal block cover.
9. See Section 18.0 for details of fitting the Optional Sensor
Accessories.
9.8
Preliminary Electrical Checks
1. Prior to commissioning the boiler preliminary electrical
system checks should be carried out.
2. These should be performed using a suitable meter, and
include checks for Earth Continuity, Resistance to Earth,
Short Circuit and Polarity.
Control Box
