Grant Combi 90, Инструкция пользователя, Страница: 13 / 20

13 Combi 90 Outdoor Module
4 - BOILER INSTALLATION
The expansion vessel fitted is supplied with a
charge pressure of 1.0 bar (equivalent to a max.
static head of 10.2 metres). The charge pressure
must not be less than the actual static head at the
point of connection. Do not pressurise the vessel
above 1.5 bar.
The air pressure in the vessel must be checked anually.
The central heating system volume, using the expansion
vessel as supplied, must not exceed 90 litres. If the
system volume is greater, an extra expansion vessel
(complying with BS 4841) must be fitted as close as
possible to the central heating return connection on the
boiler. The charge pressure of the extra vessel must be
the same as the vessel fitted in the boiler.
Refer to BS 7074:1 for further guidance.
The air charge pressure may be checked using a tyre
pressure guage on the expansion vessel Schraeder
valve. The vessel may be re-pressurised using a
suitable pump. When checking the air pressure the
water in the heating system must be cold and the
system pressure reduced to zero.
A simple test to check if the expansion vessel size is
adequate, is to fully heat the system and if the pressure
rises no more than 2.0 bar the vessel is adequate. A
higher figure indicates that an extra vessel is required.
1 Undo the two screws from the left hand cover on
the control panel to gain access to the boiler wiring
terminal block.
2 Pass the mains power supply cable through the
cable grommet into the control panel, through the
cable clamp and connect to the 12-way terminal
block as follows:-
Permanent Live (brown) to terminal 3 - marked L3
Neutral (blue) to terminal 4 - marked N4
Earth (green/yellow) to terminal 5 - marked E5
3 To control the central heating On/Off periods, it is
recommended that the boiler be wired to a single
channel timer or (programmable) room thermostat
sited at a convenient location within the property.
The switched live from the central heating control
system must be connected to terminal 1 on the 12-
way terminal block - marked S/L.
Note: When connected in this way, a link must be
added between terminals 2 and 3 - marked S/L2
and L3 to enable the burner to fire.
4 Alternatively, a two channel programmer may be
fitted to the boiler as follows:-
Switched Live Heating to terminal 1 - marked S/L1
Switched Live Hot Water to terminal 2 - marked S/L2
Permanent Live Frost stat to terminal 3 - marked L3
Mains Neutral to terminal 4 - marked N4
Mains Earth to terminal 5 - marked E5
The programmer should be of an internally
linked type.
Note: If connected in this way, the User must be
made aware that if the hot water channel is left in
the off position, hot water may not be available
upon demand and that the primary store may need
to recover before any hot water is available.
1 Select the desired fixing position for the heating
controller.
2 When fixing the wallplate remember the
connections are at the top and the vertical centre
line of the unit is at the position shown (C/L) - in
line with the terminal E. See Fig. 8.
3 Fix the wallplate to the wall or flush mounted box
as required.
4 Surface cables can only enter from below the unit. If
mounted on a flush mounted box, cables can enter
from the rear through the aperture in the wallplate.
5 Important: Links must be fitted between terminal
L and 5 and between 2 and 4. See wiring diagram
in Section 5.3.
6 Whilst the unit does not require an Earth
connection, a terminal is provided on the wallplate
for Earth continuity purposes.
7 Ensure that all dust and debris are cleared from the area.
8 Locate the module on the latches at the bottom of
the wallplate and hinge upwards to fully engage the
unit connectors into the wallplate. Tighten the two
fixing screws to secure the unit to the wallplate.
9 Before setting the programme, the unit and circuit
should be checked. Switch ON the mains electricity
supply and set the left hand rocker switch to
'CONSTANT' and the right hand rocker switch to
'ON'. Adjust any remote thermostats to check that
the services operate correctly.
Expansion vessel pressure 4.5
Connect the power supply
4.6
Connection of Grant Mini-Programmer 4.7