20
Concord CXSD/H -
Installation & Servicing
INSTALLATION
26 ADDITIONAL FEATURES OF THE CONTROL SYSTEM
27 DESCRIPTION AND OPERATION OF BOILER CONTROLS
ON / STANDBY [1/0] Button Turns the boiler on and to STANDBY.
WARNING
.
STANDBY does
NOT
electrically isolate the boiler.
When this switch is in the STANDBY position the display will show :-
On initial start up the boiler will indicate the hardware and software code, the boiler
type and indicate if the boiler is ON or at STANDBY. If the boiler is at STANDBY the
rotating information screens will not be in evidence.
To switch the boiler on press the On/Standby [1/0] button. The
display will show :-
This display will be retained for 5 seconds before the information
screens are displayed.
INFORMATION SCREENS
If the optional outside temperature kit, enabling weather
compensation, has been fitted the display will indicate the
compensated set point temperature.
An example of the display is as follows :-
MONDAY
14 : 10 19 / 09 / 95
ON HIGH 50
°
°
°
°
°
C
HOURS RUN 250
TEMP SET 82
°
°
°
°
°
C
PROGRAMMER ON
"ENTER" FOR MENU
In addition to the operational characteristics described above, the control
system incorporates the following features accessible to the user or
service engineer:
ADJUSTABLE BOILER TEMPERATURE CONTROL
This is factory preset at 82
0
C but may be adjusted by the user between
60
0
C and 85
0
C. Refer to Frame 30.
PROGRAMMER TIMER
A maximum of 3 time periods per day can be programmed in to the boiler.
Note
.
This a boiler timer only and does not replace a conventional
system programmer serving more than one heating zone.
OUTSIDE SENSOR (Optional extra)
If the optional outside sensor is fitted, the control system will recognise
this and automatically regulate the boiler flow temperature with respect
to changes in the external temperature. If the sensor is fitted, an
extra status information screen will appear stating whether the device
has been activated or not (i.e. compensator on/off).
COMMISSIONING INSTRUCTIONS
These are provided to assist the installer to commission the boiler.
SERVICING INSTRUCTIONS
These are provided to assist the service engineer.
FAULT DIAGNOSIS
In the unlikely event of a fault condition, the microprocessors will identify
the fault area and display a suitable message on the display.
Further to these accessible features there are other features present in
the system which the installer/service engineer should be aware of.
HOURS RUN LOG
This feature enables the installer to determine the workload of the boiler.
PUMP OVERRUN
If the flow temperature is above 75
o
C at the time of boiler shutdown, the
controls will maintain pump operation until the residual heat within the
appliance has been dispersed and the flow temp is below 75
o
C.
ANTI-CYCLE DEVICE
On any heating system, if the heating load is very low, there is a tendency
for the boiler to cycle on and off rapidly. This is inefficient and can lead
to shortened boiler life. The high/low operating system of the
CXSD/H
minimises the risk of this but, in addition, the controls prevent the boiler
from short cycling by preventing subsequent ignition within a period of
2 minutes. When active, the display will show:
On / standby button
Up / down buttons
Display
25 OPERATING INSTRUCTIONS
CXSD/H
features direct burner ignition, high/low burner operation, and
a microprocessor control system.
Upon a demand for heat, the controls open the low rate gas valve and
provides a rapid spark at the ignition electrode for up to 10 seconds.
The burner will light and remain at low rate for approximately 1 minute
before proceeding to high rate (when the microprocessor opens the
remaining gas valve).
If the boiler fails to light, the gas valve is closed and there will be a delay
of 1 minute before the cycle is repeated. If, after 5 attempts the burner
has failed to light, the boiler will go to lockout and 'detection fault' will be
displayed on the screen:-
When the boiler flow temperature reaches the thermostat set point, the
controls will turn the burner to low rate. If the flow temperature continues
to rise the burner will be turned off at 3
o
C above the set point.
If however the temperature falls below the set point whilst on low fire,
the controls will automatically turn the burner back up to maximum rate.
This system has the advantages of ensuring that the boiler accurately
maintains the set temperature (without the large temperature swings
that can be associated with on/off boilers), prevents rapid or short cycling,
and provides more efficient system operation.
INST
ALLA
TION
Содержание Concord CXSD 40/H
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