Checking/setting values for O
2
/CO
2
at low load
1. Measure the percentage of O
2
/CO
2
in the flue gases.
2. Compare the measured value with the checking values in the table.
Tab.35 Checking/setting values for O
2
/CO
2
at low load for G20 (H
gas)
Values at low load for G20 (H gas)
O
2
%
CO
2
%
Gas 220 Ace 160
5.2
- 5.6
8.6 - 8.8
Gas 220 Ace 200
5.2
- 5.6
8.6 - 8.8
Gas 220 Ace 250
5.2
- 5.6
8.6 - 8.8
Gas 220 Ace 300
5.2
- 5.6
8.6 - 8.8
(1) nominal value
Tab.36 Checking/setting values for O
2
/CO
2
at low load for G30/G31
(butane/propane)
Values at low load for G30/31 (butane/
propane)
O
2
%
CO
2
%
Gas 220 Ace 160
5.4
Gas 220 Ace 200
5.5
- 5.8
9.9 - 10.1
Gas 220 Ace 250
5.5
- 5.8
9.9 - 10.1
Gas 220 Ace 300
5.5
- 5.8
9.9 - 10.1
(1) nominal value
Caution
The O
2
values at low load must be higher than the O
2
values at
full load.
The CO
2
values at low load must be lower than the CO
2
values
at full load.
3. If the measured value is outside of the values given in the table,
correct the gas/air ratio.
Important
The boilers are supplied with a variety of gas valve units.
Compare the gas valve unit in the boiler with those in the drawings
and see the drawing for the position of adjusting screw B for low
load.
4. Using the adjusting screw B, set the percentage of O
2
/CO
2
for the gas
type being used to the nominal value. This should always be within
the maximum and the minimum setting limits.
Fig.60
Position of adjusting screw B
AD-0001326-02
2
1
B
2
B
1
7 Commissioning
7665063 - v.05 - 18102018
49
