Alpha CD25C Installation And Servicing Instructions page 18

4.8 CONNECT THE MAINS SUPPLY - Fig. 20
1. Gain access to the boiler terminal block by releasing the two fixing
screws (one each side) securing the control panel and lowering the
panel. Refer to Technical Data, Section 2.9 for connection details.
2. Note: This boiler has been fitted with a mains supply cable. However,
if it is necessary to fit an alternative supply cable, ensure the cable
clamp that has been fitted is removed and connect as follows:-
Remove the two screws securing the terminal block cover from the
back of the control box (see Fig. 20). Pass the mains supply cable
through the cable clamp and connect as follows:- Brown to L, Blue to
N and Green/Yellow to
Note: Ensure that the length of the earth wire is such that if the
supply cable is pulled out of its clamp the live and neutral wires
become taut before the earth wire.
The main terminal block can be removed by pulling it off the pins to
give easy access to the terminals.
Do not switch on the electrical supply at this stage.
3. If an external control, i.e. room thermostat or external clock is to be
fitted, remove the terminal block cover and remove the link between
terminals 1 and 2. Pass the cable through the cable clamp and
connect it to terminals 1 and 2. Replace the terminal block cover.
(Refer to Section 2.9).
4. Replace the terminal block, ensuring it is located correctly on the plastic pins and replace the cover.
5. Ensure that there is sufficient free cable to allow the control panel to be raised and lowered then tighten the cable clamp screws.
6. Leave the control panel open until commissioning procedures have been completed.
7. Carry out electrical system checks - Short circuit, Polarity, Earth continuity and Resistance to earth with a suitable multimeter.
4.9 FIT THE CLOCK KIT - Fig. 21
Ensure the electrical supply to the boiler is isolated.
Important: Only use an Alpha single channel clock. Do not fit a two channel clock.
1. Remove the two screws securing the clock cover at the rear of the control panel.
2. Remove and discard the clock blanking panel.
3. Insert the clock into the opening and secure in place with the screws supplied.
4. Disconnect the clock wiring from the terminal block and connect it to the clock as follows:-
Blue wire to terminal 1, Brown wire to terminal 2 and Red wires to terminals 3 and 4, (or as per the instructions supplied with
the clock). Ensure wiring is correct.
5. Replace the clock cover. Do not overtighten the fixing screws.
6. Leave the control panel open until commissioning procedures have been completed.
Alpha CD25C/28C/35C - Installation
18
. Ensure correct polarity.
Clock fixing pillars
Grommets
Cover
Fuse
Cable
clamps
Grommets
Clock cover
Rear of control panel
Fig. 21
Remove link
to connect
external
controls
Rear of
control
panel
Fig. 20