Carlin 702GAS Inst Manual - Manual (Page 19)

Model 702GAS Advanced gas burners — Instruction manual
Carlin part number MN702G Rev. 03/14/11 – 19 –
Where appliance instructions differ from this manual, follow the appliance instructions.
7. Adjust the burner using test instruments
(continued)
11. Insert the combustion equipment test probe into a vent sample opening
to sample flue products.
12. With the burner running in high fire, adjust the main gas pressure regula-
tor to achieve the values give in Table 6. Measure the CO content. It should
be no greater than 100 PPM.
High CO readings may indicate the combustion is on the
wrong side of the CO
2
curve. You will know this if a decrease
in gas pressure causes an increase in CO
2
.
Table 6 Allowable values of CO
2
and O
2
Fuel
CO
2
O
2
Minimum Maximum Maximum Minimum
Natural Gas 8.5 % 10.0 % 6.2 % 3.6 %
Propane 9.5 % 11.2 % 6.0 % 3.5 %
13. Inspect the flame
• Look at the flame through the appliance combustion chamber observation
port, if available.
• The flame should be well-defined and should not impinge on any appli-
ance surface.
• If you make air changes later, inspect the flame again.
Do not attempt to confirm combustion simply by inspecting
the flame visually. You must use combustion test instru-
ments. Failure to properly verify/adjust combustion could allow
unsafe operation of the burner, resulting in severe personal
injury, death or substantial property damage.
Step 3
Set main gas pressure regulator
1. With the gas pilot operating correctly, and the UV sensor flame signal above
minimum required, the primary control will cycle the burner to main gas.
2. Check the flame signal after the pilot has shut down to ensure the signal
is still strong with main flame on.
3. Move the burner fuel selector switch to OFF. The burner will shut down.
4. Temporarily install two U-tube manometer connections to check gas pres-
sures. Install connections at the inlet pressure tap of the main manual gas
valve and at the downstream pressure tap of the manual gas valve next to
the butterfly valve. (See items 41, page 5.)
5. The gas pressure at the inlet to the gas train must never exceed 14 inch-
es w.c., either when the burner is off or firing on gas.
6. Move the burner fuel selector switch to GAS. The burner should start.
7. Check the gas pressure at the downstream manual gas valve tapping.
Adjust the main gas pressure regulator if necessary until the gas pressure
reads:
a.
Natural gas: 3.5 inches w.c. as a starting pressure.
b. Propane gas: 2.0 inches w.c. as a starting pressure.
8. Move the low-fire switch to high fire.
Be prepared to turn the burner off immediately if it begins to
pulsate as it attempts to move to high fire.
If the flame pulsates, it is probably too rich. Switch the low-fire
switch to low fire and reduce the gas pressure by adjusting the
main gas pressure regulator. Then restart the burner with the
low fire switch in low fire as above.
If the fire is too lean, it will appear small and can even blow out
during the swing to high fire. If it blows out, shut off the burner
immediately. Switch the low-fire switch to low fire and start the
burner again. Adjust the main gas pressure regulator to increase
the gas pressure. Then restart the burner with the low fire switch
in low fire as above.
With the burner running in high fire, inspect the butterfly valve
shaft slot (Figure 18). The slot must be horizontal. IF NOT, turn
the burner off. Loosen the two hex-head screws securing the
valve linkage arm. With the damper motor linkage arm pulled
up, use a screwdriver to rotate the butterfly valve slot until it is
horizontal. Tighten the two hex head screws while still holding
the damper motor linkage arm up. Return to step 9, above.
DO NOT proceed with combustion adjustment unless the butterfly
valve position has been verified, and corrected if necessary.
9. Allow the burner to operate approximately 15 minutes to ensure the ap-
pliance is heated and combustion is steady.
10. Set the overfire draft to -.02 inches w.c., or as specified in the appliance
manual.
Figure 18 Butterfly gas valve linkage