Electrical
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can affect electronic components. Take precautions during furnace installation and service to protect the furnace’s electronic controls. Precautions will help to avoid control exposure to electrostatic discharge by putting the furnace, the control and the technician at the same electrostatic potential. Neutralize electrostatic charge by touching hand and all tools on an unpainted unit surface, such as the gas valve or blower deck, before performing any service procedure.
INTERIOR MAKE-UP BOX INSTALLATION
Figure 49
INTERIOR
Figure 50
The unit is equipped with a field makeup box. The makeup box may be moved to the right side of the furnace to facilitate installation. Seal unused openings on left side with plugs removed from right side. Secure the excess wire to the existing harness to protect it from damage.
Refer to Figure 52 for field wiring and Figure 53 for schematic wiring diagram and troubleshooting.
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
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.
Before connecting the thermostat check to make sure the wires will be long enough for servicing at a later date. Make sure that thermostat wire is long enough to facilitate future removal of blower for service.
Complete the wiring connections to the equipment. Use the provided unit wiring diagram and the field wiring diagram shown in Figure 52. Use 18 gauge wire or larger that is suitable for Class II rating for thermostat connections.
Electrically ground the unit according to local codes or, in the absence of local codes, according to the current National Electric Code (ANSI/HFPA No. 70) for the USA and current Canadian Electric Code Part 1 (CSA standard C22.1) for Canada. A green ground wire is provided in the field makeup box.
NOTE: The gas furnace contains electronic components that are polarity sensitive. Make sure that the furnace is wired correctly and is properly grounded.
Accessory Terminals
One line voltage “EAC” 1/4” spade terminal is provided on the furnace control board. Any accessory rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to one of the provided neutral terminals. If an accessory rated at greater than one amp is connected to this terminal, it is necessary to use an external relay. See Figure 54 for control board configuration. This terminal is energized when the indoor blower is operating.
One line voltage “HUM” 1/4” spade terminal is provided on the furnace control board. Any humidifier rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to one of the provided neutral
Page 34 of 48 | Issue 1031 |
