Section 2 - Burner Fan Rotation - Potterton Isis HE Installation, Operation & Maintenance Manual

SECTION 5
PAGE 22
15. The flue draught available at the appliance flue
outlet should be checked under all operating
conditions (hot and cold) and should be within
the boiler operating parameters, see Table 3
16. The fuel supply to the appliance should be
isolated and the burner operated to ensure safety
shut down and lockout of the burner on flame
failure.
17. Shut down of the boiler plant by external controls
does not cause a hazardous condition and pump
overrun is provided to remove residual heat from
the boiler.
18. Following commissioning the boiler overheat and
control thermostats should be set tot he required
operating setting. See Section 3 for maximum
operating temperature.
19. Following completion of commissioning the
soundness of all automatic fuel valves should be
checked for leakage.
Additional Checks
Where possible the system should be checked to
ensure that following purging of air there is no raw
water make-up. In particular, when the system is
operated in the hot condition, there should be no
discharge of water from the safety valve, open vent
or cold feed tank overflow that would otherwise lead
to unregulated raw water make-up when the system
cools down.
COMBUSTION ANALYSIS (Natural Gas)
When commissioning the burner the combustion
figures must be within the following limits:-
CO 9 – 9.5%
2
CO 0 – 100ppm
Flue Temp 160 220
BURNER FAN ROTATION
Prior to firing the burner check the rotation of the
burner fan is correct by starting the burner when
switching off and watching the fan slow down (refer
to burner manufacturers instructions for correct
rotation direction).
FAULT FINDING
General fault finding for burner failure should be in
accordance with the burner manufactures handbook.
Set out below are general guidance notes on system
fault finding.
POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION & MAINTENANCE MANUAL
o
C (nett)
Overheat Operation
a) The boiler/system pump is adequate for the duty.
b) Operation of flow reducing devices, ie, TRV's
compensated mixing valves, etc., do not reduce
the water flow rate through the boiler below the
minimum flow rates.
c) Pump overrun is incorporated to dissipate
residual heat from the boiler on system shut
down.
d) The operation of boiler back end valves
incorporate a time delay to allow for removal of
residual heat from the boiler.
e) The boiler is operating at the correct rate and is
not overfired.
The use of a primary loop system is highly
recommended to provide a constant boiler flow rate
under all operating conditions. For further information
refer to Potterton Publication Technical Bulletin No.1
Issue 3.
Burner Lockout
The package burners supplied with the boiler unit
have an integral safety system to allow the safe and
reliable operation of the burner. Failure of the burner
to operate correctly will cause the burner control box
to "lockout" and the lockout button on the burner will
illuminate to indicate this.
The lockout condition can be manually reset by
pushing the reset button and the control box should
restart it's control sequence in an attempt to light the
burner. If the control box lockout will not reset or
goes to lockout after being reset then the services of
a boiler repair/maintenance company should be
sought. This service is available from Potterton
Commercial Division service offices at the addresses
on the back page of this manual.
WARNING: The lockout reset button should not
be repeatedly operated otherwise a hazardous
situation may occur.
Should the boiler go to lockout, check the following
before attempting to relight the burner.
1. Fuel is available
2. The electrical supply to the appliance is of
the correct voltage and polarity.
The boiler control boxes in some instances have
indicator dials as an aid to fault finding on boiler
lockout. In these instances refer to the control box
manufacturers data sheet for fault finding details.
ISIS HE
at the burner.