Model G3B Gas burner — Instruction manual
MNG3B Gas 041015
15
Make final burner adjustments
(continued)
Check combustion using instruments
You must use combustion test instruments. Failure to properly
verify/adjust combustion could allow unsafe operation of the
burner, resulting in severe personal injury, death or substantial
property damage.
Figure 9
Flame signal measurement connections
❏
Insert test probe into vent above appliance to sample flue products.
The results should show CO
2
or O
2
as follows:
❏
If the combustion results are outside the range above, and the firing
rate of the burner is within 5% of rated input, open or close the air
throttle until the CO
2
(or O
2
) are acceptable.
After CO
2
(O
2
) tests are completed satisfactorily, measure
flue products for carbon monoxide (CO) concentration. The
CO must not exceed 50 ppm adjust to “air free”, or other if
specified by local codes.
❏
Adjust the draft in the appliance so the draft overfire is about –0.01
inch w.c. and take a flue gas sample from the combustion chamber.
If CO
2
is noticeably lower overfire than in the vent, the appliance has
leaks that must be repaired.
5. Perform Checkout Procedures • Fill Out Certificate
(continued)
Check flame signal
Electrical shock hazard — Turn off power to burner before
proceeding with setup for flame signal measurement.
❏
(See Figure 9.) The HSI is powered with 120 VAC during pre-purge
so a microammeter with a shunt switch must be used to test flame
signal or the meter will be destroyed. USE ONLY needle movement-
type meters, not digital meters.
❏
Remove the ignitor lead wire from HSI terminal of the S89C primary
control. Connect a shunt switch and
dc
microammeter between
HSI terminal and the ignitor lead wire. Make sure shunt switch is
closed
. Then turn on power to the burner. After the burner flame
starts, wait at least 15 seconds, then open shunt switch and read DC
amps (must be at least 0.8 microamps DC).
DO NOT start the burner or adjust the air throttle with the
shunt switch open. The 120 V supply to the HSI will destroy
the microammeter.
Make final burner adjustments
(continued)
Fuel
CO
2
O
2
Minimum Maximum Maximum Minimum
Natural Gas
9.6%
10.8%
4.0%
2.0%
Propane Gas
11.0%
12.5%
4.0%
2.0%