Carrier 48LC Series Service And Maintenance Instructions page 31

Table 12 – Altitude Compensation
ELEVATION
ft (m)
0 --- 2000 (610)
2000 (610)
3000 (914)
4000 (1219)
5000 (1524)
6000 (1829)
7000 (2134)
8000 (2438)
9000 (2743)
10000 (3048)
11000 (3353)
12000 (3658)
13000 (3962)
14000 (4267)
LEGEND
NG = Natural Gas
} As the height above sea level increases, there is less oxy-
gen per cubic ft. of air. Therefore, heat input rate should
be reduced at higher altitudes.
{ Not included in kit. May be purchased separately through
dealer.
Minimum heating entering air temperature
When operating on first stage heating, the minimum
temperature of air entering the dimpled heat exchanger is
50_F continuous and 45_F intermittent for standard heat
exchangers and 40_F continuous and 35_F intermittent for
stainless steel heat exchangers. To operate at lower
mixed- - air temperatures, a field- - supplied outdoor- - air
thermostat must be used to initiate both stages of heat
when the temperature is below the minimum required
temperature to ensure full fire operation. Wire the
outdoor- - air thermostat OALT (part no. HH22AG106) in
series with the second stage gas valve. See Fig. 41. Set the
outdoor- - air thermostat at 35_F for stainless steel heat
exchangers or 45_F for standard heat exchangers. This
temperature setting will bring on the second stage of heat
whenever the ambient temperature is below the thermostat
setpoint. Indoor comfort may be compromised when
heating is initiated using low entering air temperatures
with insufficient heating temperature rise.
}
(48LCL/M/N*04- - 06) - - Low NO
60,000, 90,000
BTUH Nominal
NG Orifice Size
2
38
2
39
†40
†41
†41
†42
†42
†43
†43
2
44
2
44
2
45
3
47
3
48
1 = CRLPELEV001A00
2 = CRLPELEV002A00
3 = CRLPELEV003A00
Thermostat
TH1
W1
TH2
W2
Fig. 41 - - OATL Connections
Troubleshooting Heating System
Refer to Table 13 and Table 14 for additional
troubleshooting topics.
31
Units
x
120,000
BTUH Nominal
NG Orifice Size
1
32
1
33
1
33
1
35
1
35
1
36
1
36
2
37
2
38
†40
†41
†42
†43
†43
CTB
W1
OALT
W2
C14041