Preliminary Inspections - Trane UD1A040A9241A Series Installer's Manual

Installer's Guide
▲
WARNING
!
EXPLOSION HAZARD!
PROPANE GAS IS HEAVIER THAN AIR AND MAY COL-
LECT IN ANY LOW AREAS OR CONFINED SPACES. IN
ADDITION, ODORANT FADE MAY MAKE THE GAS
UNDETECTABLE EXCEPT WITH A WARNING DEVICE. IF
THE GAS FURNACE IS INSTALLED IN A BASEMENT, AN
EXCAVATED AREA OR A CONFINED SPACE, IT IS
STRONGLY RECOMMENDED TO CONTACT A GAS
SUPPLIER TO INSTALL A GAS DETECTING WARNING
DEVICE IN CASE OF A GAS LEAK.
NOTE: The manufacturer of your furnace does NOT test any
detectors and makes no representations regarding any
brand or type of detector.
START-UP AND ADJUSTMENT

PRELIMINARY INSPECTIONS

With gas and electrical power "OFF"
1. Duct connections are properly sealed
2. Filters are in place
3. Venting is properly assembled
4. Blower door is in place
Turn knob on main gas valve within the unit to the "OFF"
position. Turn the external gas valve to "ON". Purge the air
from the gas lines. After purging, check all gas connections
for leaks with a soapy solution – DO NOT CHECK WITH
AN OPEN FLAME. Allow 5 minutes for any gas that might
have escaped to dissipate. LP Gas, being heavier than air,
may require forced ventilation. Turn the knob on the gas
valve in the unit to the "ON" position.
COMBUSTION AND INPUT CHECK
1. Make sure all gas appliances are off except the furnace.
2. Clock the gas meter with the furnace operating (deter-
mine the dial rating of the meter) for one revolution.
3. Match the "Sec" column in the gas flow (in cfh) Table 14
(page 19) with the time clocked.
4. Read the "Flow" column opposite the number of seconds
clocked. (Table 14, page 19)
5. Use the following factors if necessary:
For 1 Cu. Ft. Dial Gas Flow CFH =
For 1/2 Cu. Ft. Dial Gas Flow CFH =
For 5 Cu. Ft. Dial Gas Flow CFH =
6. Multiply the final figure by the heating value of the gas
obtained from the utility company and compare to the
nameplate rating. This must not exceed the nameplate
rating.
Gas Valve Adjustment
Changes can be made by adjusting the manifold pressure
(See Table 16), or changing orifices (orifice change may
not always be required). To adjust the manifold pres-
sure:
1. Turn off all electrical power to the system.
2. Attach a manifold pressure gauge with flexible tubing to
the outlet pressure boss marked "OUT P" on White-
18
Chart Flow Reading ÷ 2
Chart Flow Reading ÷ 4
10X Chart Flow Reading ÷ 4
Rodgers gas valve model 36G or 36J. See Figure 28 for
White-Rodgers gas valve model 36J. See Figure 27 for
White-Rodgers gas valve model 36G.
3. Loosen (Do Not remove) the pressure tap test set screw
one turn with 3/32" hex wrench.
a. The pressure tap adjustment kit (KIT07611)
contains a 3/32" hex wrence, a 5/16" hose and a
connector and can be ordered through Global Parts.
4. Turn on system power and energize valve.
5. Adjust gas heat by removing the adjustment regulator
cover screw.
a. To increase outlet pressure, turn the regulator adjust
screw clockwise.
b. To decrease outlet pressure, turn the regulator adjust
screw counterclockwise.
c. Adjust regulator until pressure shown on manometer
matches the pressure specified in Table 16.
1. The input of no more than nameplate rating and no
less than 93% of the nameplate rating, unless the unit
is derated for high altitude.
d. Replace and tighten the regulator cover screw securely.
6. Cycle the valve several times to verify regulator setting.
a. Repeat steps 5-6 if needed.
7. Turn off all electrical power to the system.
8. Remove the manometer and flexible tubing and tighten
the pressure tap screw.
9. Using a leak detection solution or soap suds, check for
leaks at the pressure outlet boss and pressure tap test
screw.
10. Turn on system power and check operation of the unit.
▲
CAUTION
!
Replace and/or tighten all plugs removed or loosened
when adjusting gas pressure. Leak check the fittings
before placing the furnace into regular service. Failure to
follow this warning could result in fire, explosion, or
property damage.
For LP gases, the final manifold pressure setting shall be
10.5" W.C. with an input of no more than the nameplate
rating and no less than 93% of the nameplate rating, unless
the unit is derated for altitude.
Table 12 (page 19) lists the main burner orifices shipped with
the furnace. If a change of orifices is required to correct the
input rate, refer to Table 13 (page 19).
TABLE 11
NATURAL GAS ONLY
TABLE OF CUBIC FEET PER HOUR OF GAS
FOR VARIOUS PIPE SIZES AND LENGTHS
LENGTH OF PIPE
PIPE
SIZE
10 20 30
1/2 132 92 73
3/4 278 190 152
1 520 350 285
1-1/4 1050 730 590
This table is based on pressure drop of 0.3 inch W.C. and 0.6 SP.GR. gas
40 50 60 70
63 56 50 46
130 115 105 96
245 215 195 180
520 440 400 370
18-CD19D7-22