Carrier 48KH - Manual (Page 11)

5. Multiply result of step 4 by the number of cu ft
shown for one revolution of test dial to obtain
cu ft of gas flow per hour.
6. Multiply result of step 5 by Btu heating value of
gas to obtain total measured input in Btuh. Com­
pare this value with heating input shown in
Table 4. Consult local gas supplier if the heating
value of gas is not known.
Example: Assume that the size of test dial is 1 cu ft,
one revolution takes 30 seconds and the heating
value of the gas is 1050 Btu perçu ft, then proceed as
follows:
a. 30 seconds to complete one revolution.
b. 30 divided into 3600 equals 120.
c.
120 times one equals 120cuft of gas flow per
hour.
d. 120 times 1050 equals 126,000 Btuh input.
If the desired gas input is 125,000 Btuh, only a
minor change in the manifold pressure is required.
Observe manifold pressure and proceed as follows
to adjust gas input:
1. Remove vented seal cap over REG ADJ screw
on gas valve.
2. Turn regulator adjustment screw clockwise to
increase gas input, or turn regulator adjustment
screw counterclockwise to decrease input. Mani­
fold pressure must be between 3.2 and 3.8 in. wg.
UNSAFE OPERATION OF THE UNIT MAY
RESULT IF MANIFOLD PRESSURE IS
OUTSIDE THIS RANGE.
3. Replace vented seal cap on gas valve.
4. Turn off gas supply to unit. Remove manometer
from pressure tap. Replace pipe plug on gas
valve. Turn on gas to unit. Check for leaks.
Measuring Manifold Pressure — LP (Propane) Gas
Units — The main burner orifices on a propane gas
unit are sized for the unit rated input when manifold
pressure is 10.5 in. wg.
Proceed as follows to adjust gas input on an LP
(propane) gas unit:
1. Turn off gas to unit.
2. Remove pipe plug on gas valve outlet identified
as PRESS. TAP, then connect manometer at this
point.
3. Turn on gas to unit.
4. Remove vented seal cap over REG ADJ screw on
gas valve.
5. Adjust regulator adjustment screw for a manifold
pressure reading of 10.5 in. wg. Turn adjusting
screw clockwise to increase manifold pressure, or
turn adjusting screw counterclockwise to de­
crease manifold pressure.
6. Turn off gas to unit. Remove manometer from
pressure tap. Replace pipe plug on gas valve, then
turn on gas to unit. Check for leaks.
ADJUSTING BURNER AIR SHUTTERS —
After burners have operated at full input for at least
10 minutes, adjust primary air to each burner to
ensure optimum heating performance. Make these
adjustments when unit is being installed and during
routine maintenance inspections at beginning of
each heating season.
Be sure each burner is clean and
free of deposits before adjusting primary air.
Primary air to each burner is regulated by burner
air shutter on each burner. See Fig. 9 for location
of burner air shutter. With all burners operating,
adjust primary air to each burner as follows:
1. Loosen locking screw that secures air shutter in
place on burner, then partially close air shutter
until a slight yellow tip appears on top of burner
flames.
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.
Table 4 — Rated Gas Inputs at Indicated Manifold Pressures
MODEL 48-
_ _ __
_ ...
KL036.042
TtH042J
_
-
KL060
. |^H(536gF7CF ■
KH048BF/CF
KH060BE
KH devoir
NUMBER
OF
ORIFICES
3
4
5
5
.. g.. ..
GAS SUPPLY
PRESSURE (in.wg)
Natural
Min
5 0
5.0
5 0
5 0
“B'O"
Max
T3”6~
13 6
Î3.B
13 6
13 6
T3 5“
13-F
LP (Propànêr
Max
T3“0 "
Min
11 0
11 0
Q-
11 0
11 0
11Ü
'ITU
13 0
13 0
13 0
130
1d.O
13 0'
MANIFOLD
PRESSURE
(in. wg)
Natural
3 5
3 5
3 5
3 5
.. gg...,
■ J5'^~
LP (Prop.)
10 5
10 5 ’
10 5
105
~ 10.5 ~
‘Based on altitudes from sea level up to 2000 feet above sea level
For altitudes above 2000 feet, reduce input rating 4% for each
1000 feet above sea level
NATURAL GAS
Heating
Orifice
P/N
LH32DB205
LH32DB205
LH32DB200'
LH32DB200
LH32DB207
tHOÎÜBZOO"
IH32DB2Ü7"
Input
(Btuh)*
40.000
60.000
■mooo"
100,000
125,000
T20dOCr
r50dO0
LP (Propane) GAS
Heating
Orifice
P/N
LH32DB201
LH32DB201
LH32DB201
LH32DB201
Input
(Btuh)*
40.000
60.000
‘Tó.odd
100,000
Not Available
IH32DB20T 120,000
Not Available
I 1