Carrier 48KLA - Page 12

2. Open air shutter very slowly until yellow tip just
disappears, then secure air shutter in place with
locking screw.
3. Repeat steps 1 and 2 for each burner.
After air shutter adjustments have been com¬
pleted, observe that flames on each burner are light
blue and soft in appearance, and that flames are
same height along entire length of each burner. See
Fig. 9.
BLOWER HEAT-RELAY OPERATION —Heat¬
ing relay (see Fig. 6 and unit wiring diagram) is
located in the control box and adjusts to permit
either longer or shorter OFF cycles. The ON cycle
automatically adjusts as OFF cycle changes. Adjust¬
ing lever on relay is factory-set at center position to
provide optimum performance for most installa¬
tions. On unusual installations, or where line voltage
is considerably above or below rated voltage, an
increase or decrease may be required for length of
time blower remains on. To increase blower opera¬
tion time, move adjusting lever toward right-hand
position. To decrease blower operation time, move
lever toward left-hand position.
AIRFLOW AND TEMPERATURE RISE — The
heating section of each size of unit is designed and
approved for heating operation within temperature
rise range stamped on unit rating plate.
Table 5 shows approved temperature rise range
for each unit and air delivery (cfm) at various tem¬
perature rises. Heating operation airflow must pro¬
duce a temperature rise that falls within the
approved range. Refer to Cooling Section Start-Up
and Adjustments — Indoor Airflow and Airflow
Adjustments to adjust heating airflow when
required.
HEATING SEQUENCE OF OPERATION —
See Fig. 10.
Models 48KHA,KLA have an intermittent
electric-spark ignition system without a standing
flame. When manual shutoff is opened, gas flows to
gas valve. On a call for heating by the thermostat,
unit terminal R makes to unit terminal W. Pilot
valve solenoid of gas valve and spark generator are
energized. Gas flows to pilot and the pilot is ignited
within 4 seconds. The flame sensor proves the
presence of pilot flame within 0.8 seconds after pilot
ignition. The internal switching of gas valve de¬
energizes spark generator, energizes main valve
solenoid and energizes heating delay relay. Gas
flows to main burners and is ignited by pilot flame.
Contacts of heating relay close between 60 and 90
seconds after burners are ignited, and blower motor
starts. Heating cycle is now in normal operation.
Unit will continue operating in heating cycle until
->
Table 5 — Air Delivery (cfm) at Indicated Temperature
Rise and Rated Heating Input
MODEL 48-
HEATING
INPUT
(Btuh)
TEMPERATURE RISE (F)
37
1 39
FI
43 45
47
49
51 53 j
55 57 59
m
iy<H
m
ca
69 :
_ I
71 ^
73 |
nr-
KLA118
40,000 751
nn
B23
B9|
617 591 567
B2U
524
505
487
KSI
mm
n
-
^ i
KLA124 40,000
794
751 712 678
646 617 591 567 m
- - -
EM
MM
Si'
- - '/' : • ::
75,000
- - - —
1212 1158
1109 | 1022
983 947 914
|§|
■ =wl
778
- -
■ -1
“ J
KLA130
40,000
mu
617 591
MU
524
505 487
BBI
K
Bi
-
- -
s
KHA030
75,000
B m
IJ^Ql
Big
1158
1109 1063
1022 983
947 914 grni -
Bi
Bi
-
— i
B
-
KLA036/136
60,000
DEI
BE3
EH
EE1
S3
mm
mi
mrM
-
Bi
BR
-
. _
-
KHA036/1 36
100,000
1EEE1
BUI
m
mm
B33 S
1263 1102
IB
MU
Hgj|
■ jgj
ma
mig
KHA036BF/CF 125,000
kb SB
| 1638 | 1579
MU
1378 1336
1296
1258 1223
KLA042/142 : 60,000
wm
%%%£&
926 887
■ an
WBEU
758 661 641 622 604
587
■ sa
mil
125,000
mu iisii
sggjjl
iiiii
1930 1846 um
iltti
KS3
| 1482 j
fgg|
1378 1326
IB
Ujjgj
§3B2
KLA048/148 j
80,000
mm
IMcKD
■ inti
naiii
■ jrn
im
_ —
Bi
Mj'
Mmum Wmmmm
■ Hi
■ HI
i.
125,000
gjjgggg
1930
llis
mu
1702 ; 1638 i
. _ I
1579
Bi
im
Qg]
mu
ibh
l&sQI
B
100,000
lUlI
nH itii
1543
1478 |
S 1417 1362
131 Oj
1263 mil
KBB
urn
EM
HU
-
EM
1 50,000
■
MM
nn
2325
ggjj
2051
1974 !
_ 1
|yvy|
1835 ]
m
HUS
m
IB
IB
UB
IB
IDS
I 1395
NOTE: Shaded areas of the table fall below the approved temperature rise range of the unit Dashed areas
of the table fa II beyond the air delivery capability of the unit within the operating voltage range for all voltage
options for each size unit
12