Combustion And Input Check; High Altitude Derate - American Standard UHMB080ACV3VB Series Installer's Manual

Installer's Guide
nace.
2. Clock the Gas Meter with the furnace operating on
high heat for one revolution. Table 18 shows the flow
rate in cubic feet per hour for a measured time of
one revolution for a meter on which one revolution
indicates 2 cubic feet per hour of gas flow. For other
meters, use the following conversions:
a. For 1 Cu. Ft. Dial Gas Flow CFH = Chart Flow
Reading ÷ 2
b. For 1/2 Cu Ft. Dial Gas Flow CFH = Chart Flow
Reading ÷ 4
c. For 5 Cu. Ft. Dial Gas Flow CFH = 10X Chart Flow
Reading ÷ 4
3. Multiply the final figure by the heating value of the
gas obtained from the utility company and compare to the
nameplate rating. This must not exceed the nameplate
rating.
4. Repeat steps 2 and 3 with the furnace operating on
low heat.
5. Changes can be made by adjusting the manifold
pressure (See Table 15), or changing orifices (orifice
change may not always be required).
TABLE 15
furnace Input rate (KBTU/hr)
60
80
100
Downflow 120
Upflow 120
For upflow 120KBTU/hr model, 1st stage is 45%
Manifold pressures apply for Natural Gas applications ONLY
furnace Input rate (KBTU/hr)
60
80
100
Downflow 120
Upflow 120
For upflow 120KBTU/hr model, 1st stage is 45%
Manifold pressures apply for Propane applications ONLY
36
HIGH ALTITUDE DERATE
CAUTION
Maintain manifold pressure as specified in Table 15 in high
altitude installations. Failure to do so may result in poor ignition
characteristics.
Input ratings (BTUH) of these furnaces are based on sea
level operation and should not be changed at elevations
up to 2,000 ft. (610m).
If the installation is 2,000 ft. (610m) or above, the furnace
input rate (BTUH) shall be reduced 4% for each 1,000 ft.
above sea level.
Installation of this furnace at altitudes above 2,000 ft.
(610m) shall be in accordance with local codes, or in the
absence of local codes, the National Fuel Gas Code,
ANSI Z223.1/NFPA 54 or National Standard of Canada,
Natural Gas and Propane Installation Code, CSA B149.1.
The furnace input rate shall be checked by using the
methods of Combustion and Input Check. High altitude
kits are listed in Table 15A.
FINAL NG MANIFOLD PRESSURE SETTINGS (inches w.c.)
40%
0.7 + 0.2 / - 0.0
0.7 + 0.2 / - 0.0
0.7 + 0.2 / - 0.0
0.7 + 0.2 / - 0.0
0.9 + 0.2 / - 0.0
FINAL LP MANIFOLD PRESSURE SETTINGS (inches w.c.)
40%
2.1 ± 0.5
2.1 ± 0.5
2.1 ± 0.5
2.1 ± 0.5
2.9 ± 0.5
18-CD30D1-20-EN
s s ! CAUTION
Table 15A
High Altitude Kit
BAYSWT07AHALTA
BAYSWT09AHALTA
BAYSWT08AHALTA
* May be "A" or "T"
65%
Not Adjustable
Not Adjustable
Not Adjustable
Not Adjustable
Not Adjustable
65%
Not Adjustable
Not Adjustable
Not Adjustable
Not Adjustable
Not Adjustable
Used with Model:
*UHMB060ACV3V
*DHMB060BCV3V
*UHMB080ACV3V
*DHMB080ACV3V
*UHMC100ACV4V
*DHMC100ACV4V
*UHMD120ACV5V
*DHMD120BCV5V
100%
3.5 ± 0.2
3.5 ± 0.2
3.5 ± 0.2
3.5 ± 0.2
3.5 ± 0.2
100%
10.0 ± 0.5
10.0 ± 0.5
10.0 ± 0.5
10.0 ± 0.5
10.0 ± 0.5