58SP0A/58SP1A: Installation, Start–Up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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a. Turn gas valve ON/OFF switch to OFF.
b. Remove manifold pressure tap plug from gas valve.
c. Connect a water column manometer or similar device to
manifold pressure tap.
d. Turn gas valve ON/OFF switch to ON.
e. Manually close blower door switch.
f. Jumper R and W thermostat connections on control to start
g. Remove regulator seal cap and turn regulator adjusting screw
counterclockwise (out) to decrease input rate of clockwise (in) to
increase input rate.
NOTE:
DO NOT set manifold pressure less than 3.2-in. w.c. or more
than 3.8-in. w.c. for natural gas at sea level. If manifold pressure is
outside this range, change main burner orifices.
h. Install regulator seal cap.
i. Leave manometer or similar device connected and proceed to
Step 4.
4. Verify natural gas input rate by clocking meter.
NOTE:
Gas valve regulator adjustment cap must be in place for proper
input to be clocked.
a. Turn off all other gas appliances and pilots served by the meter.
b. Run furnace for 3 minutes in heating operation.
c. Measure time (in sec) for gas meter to complete 1 revolution and
note reading. The 2 or 5 cubic feet dial provides a more accurate
measurement of gas flow.
d. Refer to
e. Multiply gas rate (cu ft./hr) by heating value (BTUh/cu ft.) to
obtain input.
f. If clocked rate does not match required input from Step 1,
increase manifold pressure to increase input or decrease manifold
pressure to decrease input. Repeat steps b through e until correct
input is achieved. Reinstall regulator seal cap on gas valve.
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or death.
Disconnect 115-v electrical power and install lockout tag before
changing speed tap.
Table 9 – Altitude Derate Multiplier for U.S.A.
ALTITUDE
FT. (M)
PERCENT
OF DERATE
DERATE MULTIPLIER
FACTOR*
0–2000
(0-610)
0
1.00
2001–3000
(610-914)
8–12
0.90
3001–4000
(914-1219)
12–16
0.86
4001–5000
(1219-1524)
16–20
0.82
5001–6000
1524-1829)
20–24
0.78
6001–7000
(1829-2134)
24–28
0.74
7001–8000
(2134-2438)
28–32
0.70
8001–9000
(2438-2743)
32–36
0.66
9001–10,000
(2743-3048)
36–40
0.62
EXAMPLE 1: 0–2000 ft. (0-610 M) altitude
For 22,000 BTUh per burner application use
Heating value = 1000 BTUh/cu ft.
Specific gravity = 0.62
Therefore: Orifice No. 43*
Manifold pressure: 3.7-in. w.c.
* Furnace is shipped with No. 43 orifices. In this example all main burner
orifices are the correct size and do not need to be changed to obtain proper input
rate.
