Carrier 58MVP100 - GAS VALVE AND BURNER ADJUSTMENT; Gas Valve Adjustment Procedure; Altitude Derate Calculation

UNITED STATES
At altitudes above 2000 ft, this furnace has been approved
for a 2 percent derate for each 1000 ft above sea level. See
Table 13 for derate multiplier factor and example.
EXAMPLE: 100,000 BTUH INPUT FURNACE INSTALLED AT
4300 FT.
Furnace Input Rate
at Sea Level
X
Derate
Multiplier
Factor
=
Furnace Input Rate
at Installation
Altitude
100,000 X 0.91 = 91,000
CANADA
At installation altitudes from 2000 to 4500 ft, this furnace
must be derated 5 percent by an authorized Gas Conversion
Station or Dealer. To determine correct input rate for
altitude, see example above and use 0.95 as derate multi-
plier factor.
b. Reinstall burner box cover.
NOTE: Clocking gas input rate MUST always be performed with
the burner box cover INSTALLED.
c. Check that gas valve adjustment caps are in place for
proper input to be clocked.
d. 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.
e. Check and verify orifice size in furnace. NEVER ASSUME
THE ORIFICE SIZE. ALWAYS CHECK AND VERIFY.
f. Turn off all other gas appliances and pilots.
g. Move setup switch SW-2 to ON position. (See Fig. 25.)
This keeps furnace locked in low-heat operation.
Fig. 50—Redundant Automatic Gas Valve
A97386
ON/OFF
SWITCH
INLET
PRESSURE
TAP
ON
O
F
F
BURNER
ENCLOSURE
REFERENCE
PRESSURE TAP
MANIFOLD
PRESSURE
TAP
LOW-FIRE
ADJUSTMENT
ALLEN SCREW
(UNDER CAP)
HIGH-FIRE
ADJUSTMENT
ALLEN SCREW
(UNDER CAP)
DO NOT redrill orifices. Improper drilling (burrs, out-of-
round holes, etc.) can cause excessive burner noise and
misdirection of burner flames. This can result in flame
impingement of burners and heat exchangers, causing
failures.
A93059
BURNER
ORIFICE
Fig. 51—Burner Flame
A89020
;;
;;
BURNER FLAME
BURNER
MANIFOLD
Table 13—Altitude Derate Multiplier for U.S.A.
ALTITUDE
(FT)
%OF
DERATE
DERATE MULTIPLIER
FACTOR FOR U.S.A.*
0—2000 0 1.00
2001—3000 4—6 0.95
3001—4000 6—8 0.93
4001—5000 8—10 0.91
5001—6000 10—12 0.89
6001—7000 12—14 0.87
7001—8000 14—16 0.85
8001—9000 16—18 0.83
9001—10,000 18—20 0.81
* Derate multiplier factor is based on midpoint altitude for altitude range.
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