Carrier 58MXA 170 Series - Page 47

FIRE HAZARD
Failure to follow this caution may result in reduced furnace
life, property damage, personal injury, and death.
DO NOT bottom-out gas valve regulator adjusting screw.
This can result in unregulated manifold pressure and result in
excess overfire and heat exchanger failures.
NOTE: If orifice hole appears damaged or it is suspected to have
been redrilled, check orifice hole with a numbered drill bit of
correct size. Never redrill an orifice. A burr-free and squarely
aligned orifice hole is essential for proper flame characteristics.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in component
damage due to flame impingement of burners and heat
exchangers.
DO NOT redrill orifices. Improper drilling (burrs, out-of-
round holes, etc.) can cause excessive burner noise and
misdirection of burner flames. (See Fig. 58.)
e. Replace gas valve regulator adjustment screw seal cap.
f. Replace burner enclosure front and verify adjusted gas
input rate using method outlined in item 3.
Table 10—Model 58MXA Orifice Size and Manifold Pressure for Correct Input (Continued)
for Use With 140 Size Furnaces Only
(Tabulated Data Based on 23,000 Btuh per Burner, Derated 2% for Each 1000 Ft Above Sea Level) *
ALTITUDE
RANGE
(FT)
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
SPECIFIC GRAVITY OF NATURAL GAS
0.58 0.60 0.62 0.64 0.66
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
U.S.A. Only
725 41 3.6 41 3.7 41 3.8 40 3.6 40 3.8
750 42 3.7 42 3.8 41 3.6 41 3.7 41 3.8
4001 775 42 3.5 42 3.6 42 3.7 42 3.8 41 3.6
800 42 3.3 42 3.4 42 3.5 42 3.6 42 3.7
to 825 43 3.7 42 3.2 42 3.3 42 3.4 42 3.5
850 43 3.5 43 3.6 43 3.8 42 3.2 42 3.3
5000 875 43 3.3 43 3.4 43 3.6 43 3.7 43 3.8
900 43 3.1 43 3.3 43 3.4 43 3.5 43 3.6
9% 925 43 3.0 43 3.1 43 3.2 43 3.3 43 3.4
derate 950 43 2.8 43 2.9 43 3.0 43 3.1 43 3.2
ALTITUDE
RANGE
(ft)
AVG GAS
HEAT VALUE
AT ALTITUDE
(Btu/cu ft)
SPECIFIC GRAVITY OF NATURAL GAS
0.58 0.60 0.62 0.64 0.66
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
U.S.A. Only
700 41 3.5 41 3.7 41 3.8 40 3.6 40 3.7
725 42 3.7 42 3.8 41 3.5 41 3.6 41 3.8
750 42 3.4 42 3.5 42 3.7 42 3.8 41 3.5
775 42 3.2 42 3.3 42 3.4 42 3.5 42 3.7
5001 800 43 3.7 43 3.8 42 3.2 42 3.3 42 3.4
825 43 3.5 43 3.6 43 3.7 43 3.8 42 3.2
to 850 43 3.3 43 3.4 43 3.5 43 3.6 43 3.7
875 43 3.1 43 3.2 43 3.3 43 3.4 43 3.5
6000 900 43 2.9 43 3.0 43 3.1 43 3.2 43 3.3
925 43 2.7 43 2.8 43 2.9 43 3.0 43 3.1
950 43 2.6 43 2.7 43 2.8 43 2.9 43 3.0
11% 975 43 2.5 43 2.6 43 2.6 43 2.7 43 2.8
derate 1000 43 2.3 43 2.4 43 2.5 43 2.6 43 2.7
ALTITUDE
RANGE
(ft)
AVG GAS
HEAT VALUE
AT ALTITUDE
(Btu/cu ft)
SPECIFIC GRAVITY OF NATURAL GAS
0.58 0.60 0.62 0.64 0.66
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
Orifice
No.
Manifold
Pressure
U.S.A. Only
650 41 3.8 40 3.6 40 3.7 40 3.8 39 3.7
675 41 3.5 41 3.6 41 3.7 40 3.6 40 3.7
6001 700 42 3.6 42 3.7 41 3.5 41 3.6 41 3.7
725 42 3.4 42 3.5 42 3.6 42 3.7 42 3.8
to 750 43 3.8 42 3.3 42 3.4 42 3.5 42 3.6
775 43 3.6 43 3.7 43 3.8 42 3.3 42 3.4
7000 800 43 3.4 43 3.5 43 3.6 43 3.7 43 3.8
825 43 3.2 43 3.3 43 3.4 43 3.5 43 3.6
13% 850 43 3.0 43 3.1 43 3.2 43 3.3 43 3.4
derate 875 43 2.8 43 2.9 43 3.0 43 3.1 43 3.2
* Orifice numbers 43 shown in BOLD are factory installed.
Percents of derate are based on midpoints of U.S. altitude ranges.
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