CHECKING THE QUANTITY OF GAS AT IGNITION
To check the quantity of gas at ignition, apply the following formula:
Ts x Qs
100
where
Ts = Safety time in seconds
Qs = Energy freed in safety time expressed in kW
The Qs value is obtained from:
where
Q1
= delivery expressed in liters freed in no. 10 startups in safety time.
Ts1
= total safety time of 10 startups
Qn
= Rated output
To obtain Q1, proceed as follows:
- Detach the lead from the control electrode (ionization electrode).
- Read the gas meter before the test.
- Perform 10 burner startups; these correspond to 10 safety lock-outs. Read the gas meter again; by subtracting the first
reading, the Q1 value is obtained.
Example:
First reading
Final reading
total Q1
- By performing these operations, we can find Ts1 by timing no. 1 startup (safety lock-outs) by the no. of startups.
Example:
Actual safety time = 1"95
- If, at the end of this checkup, the value is above 100, regulate the opening speed of the main valve.
CALIBRATION OF AIR PRESSURE SWITCH
The air pressure switch places the burner in safety mode or shuts it down should there be a drop in combustion air pres-
sure. It will be calibrated at a pressure below 1st stage rated-flow on-burner air pressure, checking that CO values do not
exceed 10,000 p.p.m..
CALIBRATION OF MINIMUM GAS PRESSURE SWITCH
The minimum gas pressure switch serves to prevent the burner from being started up or to shut it down if the gas pressure
falls below the minimum required level. This setting should be 40% lower than the gas pressure obtained with the burner
operating at maximum delivery.
PRESSURE SWITCH
Type: LGW 3 A2
LGW 3 A2P
GW 50 A5
GW 150 A2
GW 150 A5
Remove the cover and
adjust dial A
00006,682 liters
00006,947 liters
00000,265 liters
Ts1
= 1"95 x 10 = 19"5
P r e s s u r e
connector
- 42
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