Checks And Adjustments; Setting The Subbase; Condensate Line Raised By Base; Typical Gas Control Valve - Arcoaire N9MP1 Installation Instruction

Figure 49

Setting the Subbase

Furnace/Coil Box
Installation of
Combustible
Floor Base
Wood Screw

9. Checks and Adjustments

Verify the input rate of the furnace.
NOTE:
WARNING
!
FIRE OR EXPLOSION HAZARD.
Failure to follow this warning could result in
personal injury, death and/or property damage.
Turn OFF gas at shut off before connecting
manometer.
Startup
NOTE: Refer to the start--up procedures in the "User's Information
Manual" or to the "Operating Instructions Label" on the furnace.
WARNING
!
FIRE OR EXPLOSION HAZARD.
Failure to follow this warning could result in
personal injury, death and/or property damage.
If any sparks, odors or unusual noises occur,
immediately shut OFF power to furnace. Check for
wiring errors or obstruction to blower.
Gas Supply Pressure
Gas supply pressure should be within minimum and maximum
values listed on rating plate. Pressures are usually set by gas
suppliers.
Manifold Gas Pressure Adjustment
NOTE: Make adjustment to manifold pressure with burners
operating.
1. Remove the burner compartment door.
2. Remove the blower compartment door. Place a jumper
across furnace controls R to W. Replace blower
compartment door.
3. With gas OFF, connect manometer to tapped opening on
gas valve. Use manometer with a 0 to 15 inch water column
range.
4. Turn gas ON and remove adjustment screw cover on gas
valve. Turn adjusting screw counterclockwise to decrease
manifold pressure and clockwise to increase pressure.
42
Wood Floor
Plenum
25--20--46a
Specifications are subject to change without notice
This subbase for combustible floors has been designed so that the
height of the subbase raises the downflow coil off the floor to allow
easy installation of the condensate drain. See Figure 50.
Figure 50

Condensate Line Raised by Base

Figure 51

Typical Gas Control Valve

Regulator Adjustment
Under Cap
V
T
INLET
Inlet
Pressure
1
Tap / NPT
8
Regulator Adjustment
Under Cap
INLET
Inlet
Pressure
1
Tap / NPT
8
NOTE: Adjustment screw cover MUST be replaced on gas control
valve before reading manifold pressure and operating furnace.
5. Set manifold pressure to value as shown in Table 9,
Table 10, Table 11 or Table 12 under GAS SUPPLY AND
PIPING section in this manual.
6. When the manifold pressure is properly set, replace the
adjustment screw cover on the gas control valve.
7. Remove blower compartment door. Remove jumper wire
from thermostat connection on furnace control board.
Remove manometer connection from manifold pressure
tap, and replace plug in manifold.
8. Check for leaks at plug.
9. Replace the burner and blower compartment doors.
Natural Gas Input Rating Check
NOTE: The gas meter can be used to measure input to furnace.
Rating is based on a natural gas BTU content of 1,000 BTU's per
cubic meter. Check with gas supplier for actual BTU content.
25--20--52
Outlet
HONEYWELL
Pressure
Tap
1
/
8
OUTLET
ON
OFF
25--24--98a
Outlet
Pressure
Tap
1
/ NPT
8
OUTLET
440 01 1024 01
NPT