18
Concord CXC -
Installation
19 COMMISSIONING AND TESTING
GENERAL
Check that all drain cocks are closed, that any stop valves
fitted to the flow and return pipes are open and that the
system has been filled and properly vented. Ensure that the
caps on both secondary heat exchanger automatic air vents
are open.
Check that the shunt pump is set to maximum and that both
isolation valves are open.
PURGING
Check that the electricity supply is switched OFF.
Remove the jacket lower front panel.
Extinguish all naked lights and open all doors and windows.
The Concord CXC incorporates an advanced
microprocessor based control system which
operates all electrical functions of the boiler
including automatic ignition, flame detection,
thermostatic control, and high/low burner
operation. In addition, the microprocessor also
has onboard commissioning and servicing
instructions and a fault diagnosis programme.
The next section describes the minimum
procedure to light and commission the boiler. Full
operating instructions for the microprocessor
control and details of the high/low operation
system are included in Frames 27-30.
1. Check that the gas and electricity supplies to the boiler are
turned off.
2. Connect a gas pressure gauge to the inlet pressure test
point. (Frame 23 or 24).
3. Turn on the gas and electricity supplies. The display will
initially show a start-up code followed by;
4. Press the [1/0] button The display will change to:
then change every few seconds to indicate the boiler
status. The boiler will commence its ignition sequence.
5. The fan will start and the boiler should light, initially at low
rate, for a maximum period of 3 minutes, if less than 55°C,
before proceeding to maximum rate. If the boiler fails to
light, allow the controls to cycle until ignition is established.
If the boiler fails to light after 5 attempts, the display will
show "Detection Fault". In this case, the ignition sequence
should be reset by pressing the [COPY] button. Check that
the gas inlet pressure is at least the minimum value stated
in Table 2 when the boiler is firing at maximum rate (High).
6. Whilst the boiler is warming up, observe the display to
become familiar with its operation. The display changes
automatically between the:
"
Boiler status and flow temperature
"
Hours run
"
Temp set
"
Programmer status
"
Enter for menu
"
Day
"
Date and time
Note.
As the boiler flow temperature approaches the
thermostat setting, the boiler is automatically reduced to low
rate.
This feature is designed to improve overall operating efficiency
and reduce short cycling under low load conditions. The
controls will automatically switch the boiler between high and
low upon demand.
21 LIGHTING INSTRUCTIONS
INSTALLATION
INST
ALLA
TION
20 INITIAL LIGHTING
DO NOT SMOKE. Check that the gas supply is turned ON at
the meter and open the main gas inlet cock. Loosen the union
and allow air to be purged from the gas line until gas is
smelled. Refer to BS 6891 or IGE-UP-1 for further details.
Retighten the union.
TESTING FOR GAS SOUNDNESS
Close the gas supply cock at the meter.
Remove the screw in the inlet pressure test point (Frames 23/
24) and connect a gas pressure gauge to the test point. Take
particular care to ensure a gastight connection. Open the gas
supply cock at the meter and the appliance gas cock; record
the static pressure. Next, close the gas supply cock at the
meter. Wait for 1 minute for temperature stabilisation then
observe the pressure gauge over a period of 2 minutes.
Any leaks must be cured.
Replace all pressure test point screws.
Summary of Contents for Concord CXC 116
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