Joannes GAS 5 Manual De Uso Y Mantenimiento página 57

MAX. FLOW CONTROL
– Install a pressure gauge to measure the gas pressure
at the burner head.
– Open the gas valve to the maximum opening position.
– With burner running, adjust the stabilizer until the
required flow rate is attained (reading on the flowme-
ter) and then read the pressure value on the gauge.
– Adjust the valve closing until the pressure reading on
the gauge is likely to decrease.
Now, the maximum flow rate required is set and con-
trolled by both the stabilizer and the gas valve.
CHECKING THE QUANTITY OF GAS AT IGNITION
To check the quantity of gas at ignition, apply the following formula:
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
CHECKING THE QUANTITY OF GAS AT IGNITION
• 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.
AIR APERTURE CONTROL GEARMOTOR (JM 18/2L)
Actuation of the auxiliary contacts and limit switch contacts on the gearmotor is obtained via easily
accessible, adjustable cams. Setting of these is aided by a graduated scale.
Setting the contact trigger point.
General information.
CAM ST2 (red) – Cam for position of maximum damper aperture (maximum power with both stages
working).
CAM ST1 (blue) – Cam for position of minimum damper aperture (minimum power with only 1st stage
working).
CAM MV (black) – Auxiliary cam for 2nd stage valve aperture consensus.
Practical information on gearmotor adjustment.
The gearmotor is calibrated during final testing with the following positions:
CAM ST2: positioned at about 60°
CAM ST1: positioned so that the damper is at about 15 - 30°
CAM MV: positioned so that the solenoid valve of the 2nd stage opens when the damper is at 30 – 45°.
Ts x Qs ≥100
Q1 3600
x
Ts1 1000
Qs =
Qn
00006,682 liters
00006,947 liters
00000,265 liters
Ts1 = 1"95 x 10 = 19"5
8127
x
860
x 100
16
GB
PRESSURE
GAUGE