Installer’s Guide
HIGH ALTITUDE DERATE
Input ratings (BTUH) of these furnaces are based on sea level operation and should not be changed at eleva- tions up to 2,000 ft.
If the installation is 2,000 ft. or above, the furnace input rate (BTUH) shall be reduced 4% for each 1,000 ft. above sea level. The furnace input rate shall be checked by clocking the gas flow rate (CFH) and multiplying by the heating value obtained from the local utility sup- plier for the gas being delivered at the installed altitude. Input rate changes can be made by adjusting the mani- fold pressure (min 3.0 - max 3.7 in. W.C. - Natural Gas) or changing orifices (orifice change may not always be required). If the desired input rate can not be achieved with a change in manifold pressure, then the orifices must be changed. LP installations will require an orifice change.
Installation of this furnace at altitudes above 2,000 ft. (610m) shall be in accordance with the 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 149.1. Installation of this furnace at altitudes above 2,000 ft. (610m) shall be made in accordance with the listed high Altitude Conversion Kit available with this furnace.
IMPORTANT:
U | ROTATE THE FRONT |
| COVER AS SHOWN |
| INSERT THE TOP |
| FLANGE OF THE FRONT |
| COVER UNDER THE LIP |
| INSIDE THE BOX |
| ALL SIDE FLANGES |
| MUST BE OUTSIDE OF |
| THE BOX |
| ROTATE THE FRONT |
| COVER INWARD |
| MAKING SURE THAT |
| ALL SIDE FLANGES |
| ARE OUTSIDE OF THE |
| BOX. |
TABLE 16
GAS FLOW IN CUBIC FEET PER HOUR
2 CUBIC FOOT DIAL
SEC. | FLOW | SEC. | FLOW | SEC. | FLOW | SEC. | FLOW |
8 | 900 | 29 | 248 | 50 | 144 | 82 | 88 |
9 | 800 | 30 | 240 | 51 | 141 | 84 | 86 |
10 | 720 | 31 | 232 | 52 | 138 | 86 | 84 |
11 | 655 | 32 | 225 | 53 | 136 | 88 | 82 |
12 | 600 | 33 | 218 | 54 | 133 | 90 | 80 |
13 | 555 | 34 | 212 | 55 | 131 | 92 | 78 |
14 | 514 | 35 | 206 | 56 | 129 | 94 | 76 |
15 | 480 | 36 | 200 | 57 | 126 | 96 | 75 |
16 | 450 | 37 | 195 | 58 | 124 | 98 | 73 |
17 | 424 | 38 | 189 | 59 | 122 | 100 | 72 |
18 | 400 | 39 | 185 | 60 | 120 | 104 | 69 |
19 | 379 | 40 | 180 | 62 | 116 | 108 | 67 |
20 | 360 | 41 | 176 | 64 | 112 | 112 | 64 |
21 | 343 | 42 | 172 | 66 | 109 | 116 | 62 |
22 | 327 | 43 | 167 | 68 | 106 | 120 | 60 |
23 | 313 | 44 | 164 | 70 | 103 | 124 | 58 |
24 | 300 | 45 | 160 | 72 | 100 | 128 | 56 |
25 | 288 | 46 | 157 | 74 | 97 | 132 | 54 |
26 | 277 | 47 | 153 | 76 | 95 | 136 | 53 |
27 | 267 | 48 | 150 | 78 | 92 | 140 | 51 |
28 | 257 | 49 | 147 | 80 | 90 | 144 | 50 |
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