Hamworthy Sherborne Series, Installation, Commissioning And Service Manual

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HAMWORTHY HEATING LTD
SHERBORNE 500001103/E
11.5.2 Procedure For Initial Lighting
Ensure gas service valve is in the "OFF" position and
the electricity supply to the boiler is isolated. Remove
the fascia on the control panel and secure on the two
hooks on the panel body. Rotate SW1 until the arrow
points towards ‘A’ -- refer to fig 9.1. Link terminals R1
to R2 and R3 to R4 -- refer to fig 9.1. (Note this linking
scheme will operate the boiler at full rate, to achieve
running at reduced rate remove link between R3 and
R4). Energise electrical supply and press lockout
button on fascia to re-set the controls, (wait at least 15
seconds before pressing again if the lockout neon is
not extinguished). Press the control thermostat knob to
switch on the boiler and turn fully clockwise. The
combustion fan will start and run for a purge period
(approximately 20 seconds). During this time the 'fan
on' neon should illuminate. After a delay, the HSI
system will operate causing the igniter to glow (visible
through the viewing port) for a period (approximately
10 seconds). As the gas service valve is closed, the
controls should go to lockout after a further 5 seconds
(red neon on fascia illuminated). If the above occurs
correctly, OPEN the service valve and press re-set
button on fascia.
After the purge period the ignition should be initiated
and main gas valve will energise lighting the main
burner.
Note! the multi-meter should be reading at
least 2µA. The boiler will operate at its start rate for 15
seconds before commencing modulation.
11.5.3 After the boiler has operated for approximately
10 minutes, press the control thermostat knob to
switch off the boiler, and connect a manometer to the
pressure test point
on the gas valve inlet . Re-light the
module checking the inlet pressure, see Figure 2.2. No
adjustment of the gas valve is permissible.
For Natural Gas the gas pressure governor control
system is configured for a nominal gas inlet pressure
of 20mbar measured at the inlet to the gas valve, with
a maximum inlet pressure of 25mbar.
For propane firing models, the nominal gas inlet
pressure is 37mbar with a maximum inlet pressure of
45mbar.
Switch “OFF” the module, disconnect the manometer
and close the pressure test point. Record all readings
for future reference on the relevant commissioning
sheet.
Isolate the electrical supply and rotate SW1 to set the
required mode of operation for the boiler. Make/Break
links R1 to R4 as dictated by site requirements. Re-
energise electrical supply and switch on the boiler and
allow system to warm up sufficiently to check operation
of control thermostat.
If an optional Sequencing Interface Module is fitted to
the boiler control panel turn rotary switch ‘SW1’ on the
boiler main control PCB to position ‘1’ for fully
modulating sequenced operation. Also ensure that the
rotary switch ‘SW1’ on the Sequencing Interface
Module PCB is set to position ‘0’.
11.5.4. A combustion check must be taken when
first commissioning the boiler . To achieve the
specified combustion results, a plugged sample hole is
provided in the sump casting panel adjacent to the flue
outlet.
NOTE! Care should be exercised if the boiler is firing
as the flue can achieve temperatures which can cause
injury if touched.
Combustion figures for Natural Gas should be as
follows :-
CO
2
= 8.5-9.0% (Dry flue gas)
O
2
= 5 - 6%
CO = 0-65ppm: However figure should not exceed
200ppm under normal operating conditions.
Note an approximation of boiler heat input implied from
the displayed fan speed can be determined using
figure 11.5.4. For exact determination a gas meter
should be used.
For LPG Propane firing - See Appendix ‘A’.
Figure 11.5.4 Fan Speed VS Boiler Input
LPG Operation
Nat Gas Operation
0 1000 2000 3000 4000 5000
0
10
20
30
60
50
40
70
80
Fan speed rpm
In
pu
t (k
W
net
t)
11.5.5 To check for correct operation of the controller,
break the multi-meter µA circuit. The boiler should
lockout after approximately one second. Check that
the flame has been extinguished. With the fascia panel
removed, dis-connect the multi-meter and replace wire
link and front cover. Wait at least 15 seconds before
pressing re-set button on fascia to re-set controller.
After a waiting period the boiler will light and run
normally.
11.6 External Controls
The external controls used in typical boiler
installations, for both vented and unvented systems,
are shown in Figure 1.1. If different systems or controls
are to be used and there are any doubts as to the
suitability, contact Hamworthy Heating Technical
Department for advice.
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