REMEHA Avanta Plus 24s, Installation And Service Manual

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R
A
4. Checking/setting the gas/air ratio at full load
The Avanta Plus boilers are suitable for both natural gas and
propane firing. For the Avanta Plus 39c an optional propane-
set is needed.
The boilers are supplied as standard set for natural gas
(H), therefore the following procedure must be carried out
BEFORE the boilers are fired and commissioned for the first
time on propane:
-
adjust the fan speed ( for procedure; see Par. 2.9.8, for
values; see table 06 and table 08) and;
- adjust the gas/air ratio ( for values; see table 06 and table 08 ).
LT.AL.W7H.000.042
Setting values O
2
/CO
2
for natural gas H / L
Boiler type
Fan speed (rpm) O
2
CO
2
Full load h3 *)
% %
24s approx. 4300
5.2
± 0.1
8.8
± 0.1
28c approx. 5500
5.2
± 0.1
8.8
± 0.1
35c approx. 6300
5.2
± 0.1
8.8
± 0.1
39c approx. 6700
5.2
± 0.1
8.8
± 0.1
table 05 Setting values full load CO
2
and O
2
(front panel not
fi tted)
Setting values O
2
/CO
2
for LPG (propane)
Boiler type
Fan speed (rpm) O
2
CO
2
Full load h3 *) % %
24s approx. 4100
5.1
± 0.3
10.5
± 0.3
28c approx. 5200
5.1
± 0.1
10.5
± 0.3
35c approx. 5800
5.1
± 0.3
10.5
± 0.3
39c approx. 6500
5.1
± 0.3
10.5
± 0.3
table 06 Setting values full load CO
2
and O
2
(front panel not
fi tted)
*) On forced full load, the 2
nd
digit indicates the operating code
•
Unscrew the flue gas sampling cap and connect the flue gas
analyser.
•
Set boiler to full load.
•
Press the [enter]- key, keep it pressed and also press the
[+]- key until h3 appears in the display; full load has been
set.
•
Once the unit has reached the full-load fan speed, measure
the O
2
/CO
2
-percentage and compare this to the values in
table 05.
• If the values are not in accordance with the table then correct
the gas /air ratio controls using the adjusting screw A on the
gas block.
• If the value is too low turn the screw A anti clockwise; this
increases the gas rate – if the value is too high turn the screw
clockwise which decreases the gas rate.
•
Check the flame through the sight glass which should be sta-
ble with a regular blue distribution.