BURNER
ORIFICE
A93059
DO NOT redrill orifices. Improper drilling (burrs,
e.Move setup switch
f.Jumper R and W2 thermostat connections on control center. (See Fig. 14.) This keeps furnace locked in
g.Turn
NOTE: DO NOT set
h.When correct input is obtained, replace caps that conceal gas valve regulator adjustment screws. Main burner flame should be clear blue, almost transparent. (See Fig. 20.)
i.Remove jumper R to W2.
4.Verify natural gas input rate by clocking gas meter.
a.Calculate
UNITED STATES
At altitudes above 2000 ft, this furnace has been approved for a 4 percent derate for each 1000 ft above sea level. See Table 9 for derate multiplier factor and example.
Table 9—Altitude Derate Multiplier for U.S.A.
ALTITUDE | % OF | DERATE MULTIPLIER |
(FT) | DERATE | FACTOR FOR U.S.A.* |
0 | 1.00 | |
0.90 | ||
0.86 | ||
0.82 | ||
0.78 | ||
0.74 | ||
0.70 | ||
0.66 | ||
0.62 |
* Derate multiplier factor is based on midpoint altitude for altitude range.
EXAMPLE:
85,000 Btuh input furnace installed at 4300 ft.
Furnace Input |
| Derate |
| Furnace Input Rate |
Rate at | X | Multiplier | = | at Installation |
Sea Level |
| Factor |
| Altitude |
85,000 | X | 0.82 | = | 69,700 |
CANADA
At installation altitudes from 2000 to 4500 ft, this furnace must be derated 10 percent by an authorized Gas Conver- sion Station or Dealer. To determine correct input rate for altitude, see example above and use 0.82 as derate multi- plier factor.
b. Check that gas valve adjustment caps are in place for proper input to be clocked.
c. Obtain yearly heat value average for local gas supply.
NOTE: Be sure heating value of gas used for calculations is correct for your altitude. Consult local gas utility for altitude adjustment of gas heating value.
d. Check and verify orifice size in furnace. NEVER AS-
SUME THE ORIFICE SIZE. ALWAYS CHECK AND VERIFY.
e.Turn off all other gas appliances and pilots.
f.Move setup switch
g.Jumper R to W/W1.
h.Let furnace run for 3 minutes in
i.Measure time (in sec) for gas meter to complete 1 revolu- tion. Note reading.
j.Refer to Table 10 for cubic ft of gas per hr.
k.Multiply gas rate cu ft/hr by heating value (Btu/cu ft).
l.Move setup switch
EXAMPLE:
Btu heating input = Btu/cu ft X cu ft/hr Heating value of gas = 1050 Btu/cu ft Time for 1 revolution of
Btu heating input = 80 X 1050 = 84,000 Btuh In this example, the orifice size and manifold pressure adjustment is within ±2 percent of the furnace input rate.
NOTE: Measured gas inputs (high heat and low heat) must be within ±2 percent of that stated on furnace rating plate when installed at sea level or derated per that stated above when installed at higher altitudes.
m. Remove jumper across R, W/W1, and W2 thermostat connections to terminate call for heat.
5.Set temperature rise.
Place
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