Combustion Adjustment Procedure; Damper Terminals Explained - Beckett CG15 Manual

Combustion Adjustment Procedure

Always use calibrated test instruments to set combustion
levels. Verify that test instruments are calibrated and in
good working condition. If not already provided, drill test
access holes in the flue pipe near the breech (or upstream
of the boiler breech damper, if applicable) and in the front
mounting plate area for firebox pressure. Be careful not to
damage any water-backed surface.
Verify that all appliance sections, canopy, and access
plates or doors are fully equipped with gaskets and
sealed against any leakage, which could affect the
combustion test results. Before making these tests,
operate the burner to allow the heating system
temperature to stabilize or nearly reach steady-
state levels. Record all results in the start-up log for
future reference.
Combustion Adjustment Procedure
• Oxygen – It is recommended that you measure the
oxygen (O2) early in the test sequence because
high levels of carbon monoxide can be created at
very low or even very high O2 levels. The typical
operating range is between 3% – 5%.
• Carbon monoxide (CO) – An operating range of 0
to 50 PPM is recommended for the gas burner. The
maximum carbon monoxide (CO) level permitted
in the flue gas by the UL 795 Standard is 400 PPM
(.04%).
• Stack Temperature – The stack temperature must
be within the range specified by the appliance
manufacturer. Generally a 325°F stack temperature
is high enough to avoid corrosive condensation in
the vent system, however a large cross sectional
flow area chimney or a very tall chimney may require
a higher temperature.
1. Initiate a call for heat.
2. Adjust the burner
Set the damper motor Blue, Red, and Orange dials
to correct settings (see OEM Spec Guide). Start
burner. Watch to see damper motor move to Low
Fire setting. If it doesn't move, turn burner off.
Open air damper blade and then restart the burner.
Once burner is operating, allow it to warm up the
boiler before switching it to High Fire. Please meet
the following results (see Figure 21 and Figure 19 .
3. Adjust the draft or breech pressure to the appliance
manufacturer's recommended level after flame
has stabilized.
4. Measure the carbon monoxide level and adjust air
settings, if necessary, to temporarily raise CO to
26 — Section: Start Up And Operation
about 50 PPM for a test point.
5. Measure the O2 or CO2 at the 50PPM CO level.
6. Open the air adjustment until the O2 level is
increased by at least 1% or to 3% O2 (whichever
is higher). This should reduce the CO level and
provide a margin of reserve air to accommodate
variable conditions.
For gas valve adjustment instructions, refer to the
manufacturer's literature.
7 . Sample the CO level again. It should be in the 0 to
20 PPM range (must be below 50 ppm)
8. Check the draft to ensure it still meets specifications.
If a major change in draft is required, repeat the
above steps.
9. Check draft regulator for spillage. Confirm the
condition of the chimney if spillage is present.
10. Verify stack temperature meets appliance
manufacturer's recommendations.
11. Perform any final adjustments and lock the
air settings securely. Run the burner through
several cycles to verify prompt ignition and stable
burner operation.

Damper Terminals Explained

Figure 19 — Damper Actuator Terminals
Terminal Explanation
N Neutral
4 Not Used for Beckett's low/high burners
3 Not Used for Beckett's low/high burners
2 120v When the burner is in Low Fire
1 120v When the burner is in High Fire
120v When the Valve circuit from the control gets
5
energized (After Pre Purge)
7 Not Used for Beckett's low/high burners
120v When the burner is in High Fire. This powers
the high rate valve. Orange cam must be in
between the Blue and Red cams.
6
If there is no Voltage here in High Fire, make sure
the Orange cam is between the Blue and Red
Cams.
CG15, CG25, CG50 Burner Manual, Form No. 6104BCG50