Glow-worm BBU 54/4 - Manual (Page 18)

18 2000225024C
Diagram 6.2
9608
ADJUSTER “G”
GAS
CONTROL
VALVE
GAS SERVICE COCK “C”
(SHOWN IN THE OFF
POSITION)
GAS FIRE
SUPPLY COCK "D"
CAP
RESTRICTOR
SCREW
WASHER
Technical Sequence of Operation
When an external control calls for heat there is approximately
a 5 second delay. The control board (PCB) energises the 1st
gas valve solenoid, the valve will open and the spark unit will
operate. With the valve open, gas is allowed to pass to the flue
blockage safety device that will be ignited by the sparks. This
ignition attempt will continue until the micro-ampage generated
at the sense electrode is sufficient to satisfy the board. At this
point the spark unit is de-energised and the green light on the
boiler user control will light up, see diagram 6.1. The main gas
control valve is energised through the control board and main
burner lights. When the water temperature has reached the set
point the control thermistor instructs the control board to close
the gas valve.
NOTE. If the electrical supply is switched rapidly off and on
without gas present the control will purge for 100 sec. Neither
of the indicators will be lit. The appliance will then operate
correctly.
When the water temperature has reduced to a set point the
control thermistor will instruct the control board to restart
ignition.
The boiler will continue to cycle in this manner until the external
control stops its demand for heat. At this point external power
is removed and the board switches off.
Check the pilot flame is stable and has a length as shown in
diagram 6.3.
Note: Should the red light on the back boiler control panel come
on, it indicates that the pilot light is not operating correctly, or the
flue blockage safety device has been activated, see diagram
6.1.
When the fault has been corrected, turn the control thermistor
knob "A" fully anti-clockwise so that the pointer is against the
"Reset" position on the back boiler user interface, see diagram
6.1.
Turn the control thermistor knob "A" fully clockwise to maximum
on the back boiler user control. After a delay the unit will restart
the ignition sequence.This is indicated by the green light on the
boiler user interface coming on, see diagram 6.1.
The main burner will light.
Test for gas soundness using a suitable leak detection fluid.
The back boiler is supplied preset to a maximum heat output
setting of 14.21 kW (48500 Btu/h) but may be adjusted to suit
design requirements.
This value is permitted and must not be increased when using
the boiler in combination with a Chatsworth 4 and a Dovedale
4 firefront.
For Firelite 4, Contour 4, Miami 4, Heartbeat 4 or Black Beauty
4 fire front the output may be increased to 15.82 kW
(54000 Btu/h).
If adjustment is required, TEN MINUTES after lighting, turn
adjustment screw “G” anti-clockwise to suit system design heat
input, see diagram 6.1 and 6.2.
Should any doubt exist, the gas rate should be checked at the
gas meter.
The rate of the back boiler should be within the range:
For Firelite 4, Contour 4, Miami 4, Heartbeat 4, Black Beauty 4
1.88m 3 /h (65.5ft 3 /h) to 1.45m 3 /h (51.15ft 3 /h)
For Chatsworth 4, Dovedale 4:
1.68m 3 /h (59.3ft 3 /h) to 1.27m 3 /h (44.9ft 3 /h)
Note, if the gas rate is checked, make sure that all other gas
appliances and pilot lights are turned off.
Turn control thermostat knob "A" anti-clockwise to the "Reset"
position. Remove pressure gauge and replace test point screw
ensure a gas tight seal is made.
Relight the back boiler by turning control thermostat knob "A"
clockwise to maximum.
Use the self-adhesive arrow from the fittings pack and stick it
against the relevant heat input figure on the Data Label.
LIGHTING: SEQUENCE OF OPERATION
1. Switch on the electrical supply to the boiler
and heating sytsems.
2. Set external controls if fitted, to demand heat.
3. Turn the boiler control thermistor knob
fully clockwise to the maximum setting.
The lighting sequence is automatic as follows:-
4. Approximate 30 second delay.
5. Ignition initiated sparking at electrode
EV1 energised, (Pilot solenoid)
pilot lights.
6. EV2 energised, (Main burner solenoid)
main burner lights.
9555
6 Commissioning