Laars MASCOT LX, Руководство по обслуживанию

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72
Mascot LX Service Manual
Combustion Adjustment Procedure
DANGER
Improper adjustment may lead to poor combustion
quality, increasing the amount of carbon monoxide
produced. Excessive carbon monoxide levels may
lead to personal injury or death.
Equipment required:
• Combustion analyzer
• 2.5 mm Allen wrench
• 4 mm Allen wrench
Replacement procedure:
1. Create an active “Call For Heat” signal so the unit
is always firing. On the low voltage terminal strip,
insert a jumper between terminals 3 and 4. See Fig.
C2-1.
2. Take the controller to Service mode. Press and hold
the OK/ Select button and the Up buttons for five
seconds.
3. The next job is to measure the CO
2
and O
2
in the
flue products at High Fire. To do this, the Mascot LX
must be forced go to High Fire. Use the Up arrow
to increase the firing rate to 100%. (All of the seg -
ments in the flame image will be lighted.) Figure
C2-2 shows the type of display you should see.
4. The CO
2
readings should be between the values
shown in Table C2-1. If the CO
2
is not within the
range shown, you must make some adjustments.
Remove the upper front panel so you can reach the
gas valve shown in Fig. C2-3.
To adjust the high fire CO
2
, locate the high fire
adjuster screw shown in Fig. C2-3. Use the 2.5 mm
Allen wrench. Slowly make adjustments in 1/16 of
a revolution increments until the CO
2
is within the
range shown in the table.
Gas Type High Fire CO
2
Low Fire CO
2
Natural 8.9% to 9.9% 0.5% lower than high fire CO
2
Propane 9.9% to 10.9% 0.5% lower than high fire CO
2
Table C2-1 - CO
2
Range
C2
Fig. C2-1 - Jumper location for “call for heat”
Insert a jumper between
terminals 3 and 4
Fig. C2-2 - Control display during “high fire”
5. Next you need to measure the CO
2
and O
2
in the
flue products at Low Fire. Use the Down arrow to
reduce the firing rate to 20%. You can also use the
OK/Select button to toggle between high fire and
low fire. (At low fire, only the smallest segment in the
flame image will be lighted.)
The CO
2
readings should be between the values
shown in Table C2-1. If the CO
2
is not within the
range shown, you must make some adjustments. To
adjust the Low Fire CO
2
, use the 4 mm Allen wrench
to turn the Low Fire adjuster screw shown in Fig. C2-
3. Slowly make adjustments in 1/16 of a revolution
increments until the CO
2
is within the range shown in
the table.
Service mode symbol