37
20148049
GB
Maintenance
7.1
Notes on safety for the maintenance
The periodic maintenance is essential for the good operation,
safety, yield and duration of the burner.
It allows you to reduce consumption and polluting emissions and
to keep the product in a reliable state over time.
Before carrying out any maintenance, cleaning or checking
operations:
7.2
Maintenance programme
7.2.1
Maintenance frequency
7.2.2
Safety test - with no gas supply
To perform commissioning in safety conditions, it is very
important to check correct wiring between gas valves and burner.
For this purpose, after checking that connections comply with the
burner wiring diagrams, it is necessary to carry out a start-up
cycle with gas cock closed (dry test).
1
The manual gas valve must be closed using the locking/
unlocking device (“Lock-out / tag out” procedure).
2
Ensure that burner limit electrical contacts are closed
3
Ensure that minimum gas pressure switch contact is closed
4
Try to start the burner
The start-up cycle must occur according to the following steps:
–
Fan motor start-up for pre-purging
–
Gas valve leak detection control, if applicable
–
Pre-purging completion
–
Achievement of the ignition point
–
Power supply of the ignition transformer
–
Supply of gas valves
As gas is closed, the burner cannot ignite and its control box will
switch to stop or safety lockout condition.
The actual supply of gas valves can be checked by inserting a
tester; some valves are equipped with lights (or closing/opening
position indicators) that activate as soon as they are powered.
7.2.3
Checking and cleaning
Combustion
Carry out an analysis of the combustion flue gases.
Significant differences with respect to the previous
measurements indicate the points where most care should be
exercised during maintenance.
Combustion head
Open the burner and make sure that all components of the
combustion head are in good condition, not deformed by the high
temperatures, free of impurities from the surroundings and
correctly positioned.
Burner
Check for excess wear or loose screws in the mechanisms
controlling the air damper and the gas butterfly valve.
Also make sure that the screws securing the electrical leads in
the burner terminal block are fully tightened.
Clean the outside of the burner, taking special care with the
articulated couplings and the cam 4)(Fig. 38 on page 32).
7
Maintenance
DANGER
The maintenance interventions and the calibration
of the burner must only be carried out by qualified,
authorised personnel, in accordance with the
contents of this manual and in compliance with the
standards and regulations of current laws.
DANGER
Disconnect the electrical supply from the burner
by means of the system main switch.
DANGER
Close the fuel shut-off valve.
Wait for the components in contact with heat
sources to cool down completely.
The gas combustion system should be checked at
least once a year by a representative of the
manufacturer or another specialised technician.
ATTENTION
IF POWER SUPPLY OF GAS VALVES
OCCURS IN UNEXPECTED MOMENTS, DO
NOT OPEN THE MANUAL VALVE,
DISCONNECT POWER SUPPLY, CHECK
WIRINGS, CORRECT THE ERRORS AND
CARRY OUT THE WHOLE TEST AGAIN.
The operator must use the required equipment
during maintenance.
