23
Concord Super Series 4 -
Installation & Servicing
IMPORTANT:
The gas setting pressures MUST NOT be reset to the values
given in the following section unless the differential air
pressure is greater than 1.1 mbar (in.w.g.).
FIRING CHECKS (Frames 14, 16 & 17)
i.
The minimum gas pressure in the gas header
should be 15 mbar (6 in.w.g.) with all modules
firing. The maximum pressure should not exceed
25 mbar (10 in.w.g.).
ii.
The draught stabiliser should be set to control
between neutral and 0.2 mbar (0.08 in.w.g.) draught
in the casing, with one or all modules firing.
A test point is provided in the boiler casing adjacent to the flue
outlet socket.
Carry out the following firing checks on each individual
module, commencing with the top left module and finishing
with the bottom right. Ensure that the boiler is full of water and
that the main and any boiler primary pumps are running.
1.
Swing out together as one unit the inner and outer
front panels by releasing the single M5 screw (see Frame
19) observed through the panel right-hand cutaway. This
screw fastens the inner front panel to the fan plate.
2.
Connect a manometer to the pressure test point at the
outlet end of the gas valve (Frame 20).
3.
Connect a manometer to the pressure test point at the
inlet end of the gas valve.
4.
Turn on the module service gas tap and mains inlet gas
tap.
5.
Switch ON the boiler mains isolator and put the module
on/off switch to ON. The following sequence of events
should occur:
a. The mains ON light will illuminate.
b. For multi-module boilers.
The fan will start and run for approximately 30 seconds
(part 3 of the volume air change safety feature) then stop
for 1 - 50 seconds, depending upon the modules position
in the switching sequence. It will then re-start and run for
approximately 15 seconds.
For single module boilers
The fan will start and run for approximately 15 seconds. If
the lockout warning light illuminates at this stage press the
lockout reset button.
c.
The ignition period will commence, the gas valves will
open and a spark will be generated between the ignition
electrode and the burner (visible through the
sight
glass).
d.
The burner will light and the burner ON light will be
illuminated.
If the burner fails to light, the lockout light will be illuminated at
the end of the 4 second ignition period and the fan will run on.
Another attempt at ignition can be made by waiting 10
seconds and then pressing the lockout button.
After 10 - 20 seconds of pre-purge fan run sequence (c) and
(d) will be repeated. Should any module still not fire and the
gas line has been properly purged, refer to the fault finding
instructions.
6.
When the burner is firing allow the module to run for at
least 3 minutes. The gas valve outlet pressure should then
be 6.8 mbar (2.7 in.w.g.) and the gas valve inlet pressure not
less than 13.5 mbar (5.4 in.w.g.). A valve inlet pressure of less
than 13.5 mbar indicates either a manifold pressure below the
minimum 15.0 mbar (6.0 in.w.g.) or a part blockage between
manifold and valve inlet.
COMMISSIONING AND TESTING
Summary of Contents for Concord Super Series 4 50 V
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Page 39: ...37 Concord Super Series 4 Installation Servicing ...
