Leak Check
After gas piping is completed, carefully check all piping connections (factory− and field−installed) for gas leaks. Use a leak detecting solution or other preferred means.
NOTE − If emergency shutoff is necessary, shut off the main manual gas valve and disconnect the main power to the furnace. The installer should properly label these devices.
CAUTION
Some soaps used for leak detection are corrosive to certain metals. Carefully rinse piping thoroughly af- ter leak test has been completed. Do not use matches, candles, flame or other sources of ignition to check for gas leaks.
The furnace must be isolated by closing its individual manual
IMPORTANT
When testing pressure of gas lines, gas valve must be disconnected and isolated. See figure 28. Gas valves can be damaged if subjected to pressures greater than 1/2 psig (3.48 kPa, 14 inches w.c.).
MANUAL MAIN | ISOLATE | |
SHUT−OFF VALVE | ||
GAS VALVE | ||
WILL NOT HOLD | ||
FURNACE | ||
NORMAL TEST | ||
| ||
PRESSURE |
| |
1/8 NPT PLUG |
|
CAP
FIGURE 28
Electrical
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can affect electronic com- ponents. Take precautions during furnace installa- tion and service to protect the furnace’s electronic controls. Precautions will help to avoid control ex- posure to electrostatic discharge by putting the fur- nace, the control and the technician at the same electrostatic potential. Neutralize electrostatic charge by touching hand and all tools on an un- painted unit surface, such as the gas valve or blower deck, before performing any service procedure.
The unit is equipped with a field make−up box on the left hand side of the cabinet. The make−up box may be moved to the right side of the furnace to facilitate installation. If the make−up box is moved to the right side, clip the wire ties that bundle the wires together. The excess wire must be pulled into the blower compartment. Secure the excess wire to the existing harness to protect it from damage.
INTERIOR MAKE−UP BOX INSTALLATION
Right Side
BOX
FIGURE 29
INTERIOR MAKE−UP BOX INSTALLATION
Left side
BOX
FIGURE 30
Refer to figure 32 for schematic wiring diagram and trou- bleshooting and figure 33 for field wiring.
The power supply wiring must meet Class I restrictions. Protected by either a fuse or circuit breaker, select circuit protection and wire size according to unit nameplate.
NOTE − Unit nameplate states maximum current draw. Maximum over−current protection allowed is 15 AMP.
Holes are on both sides of the furnace cabinet to facilitate wiring.
Install a separate (properly sized) disconnect switch near the furnace so that power can be turned off for servicing.
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