Lennox International Inc CBWMV Electrostatic Discharge ESD Precautions And Procedures

Electrostatic Discharge (ESD) - Precautions And Procedures

CAUTION

Electrostatic discharge can affect electronic com- ponents. Take precautions during air handler instal- lation and service to protect the air handler’s elec- tronic controls. Precautions will help to avoid con- trol exposure to electrostatic discharge by putting the air handler, the control and the technician at the sameelectrostaticpotential.Neutralizeelectrostatic charge by touching hand and all tools on an un- painted unit surface, such as the blower deck, be- fore performing any service procedure.

Refer to table 3 for field wiring.

1.Refer to the CBWMV unit’s nameplate for minimum circuit ampacity and maximum overcurrent protection size.

2.Install a separate disconnect switch (protected by ei- ther fuse or circuit breaker) near the air handler so that power can be turned off for servicing.

3.Complete the wiring connections to the equipment. Use the provided unit wiring diagram and the field wir- ing diagrams shown in table 3. Use 18−gauge wire or larger that is suitable for Class II rating for thermostat connections.

4.Electrically ground the unit according to local codes or, in the absence of local codes, according to the current

National Electric Code (ANSI/NFPA 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 make−up box.

5.Install the room thermostat according to the instruc- tions provided with the thermostat. See table 3 for field wiring connections in varying applications. If the air

handler is being matched with a heat pump, refer to the FuelMaster21® installation instruction.

Removeable Jumpers

Removeable Jumper DS to Y1 The factory−installed wire jumper that connects terminals DS and Y1 on the TB1 terminal strip in the control box must be removed when the air handler is installed in a system supporting dehumidifi- cation using a SignatureStatt thermostat (e.g., Humidi- trol® Enhanced Dehumidification Accessory or Harmonyt zone controls).

Removeable Jumper R to O The factory−installed wire jumper that connects TB7 (24V) terminal R to TB1 termi- nal O must be removed when the air handler is installed in applications which include a heat pump unit and the Fuel- Master21® control board. If the jumper is left intact, termi- nal O will remain energized, eliminating the heat mode in the heat pump.

Removeable Jumper Y1 to Y2 The factory−installed wire jumper that connects Y1 and Y2 on the TB1 terminal strip must be removed if two−stage cooling is used. If the jumper is not removed the outdoor unit will only operate in second−stage cooling.

Table 3

Field Wiring Application Jumper Settings (See figure 12)

Thermostat (Application) TB1 Y1 to Y2 TB1 DS to Y1 TB1 R to O Wiring Connections

1 Heat / 1 Cool with	Yes	No	No	SignatureStatt CBWMV	OUTDOOR
SignatureStatt Thermostat		(Remove)	(Remove)	TERMINALS	UNIT
[Single-Stage Heat Pump]
					JUMPERS
					REMOVED

2 Heat / 2 Cool with	No	No	No	SignatureStatt CBWMV	OUTDOOR
SignatureStatt Thermostat	(Remove)	(Remove)	(Remove)	TERMINALS	UNIT
[Two-Stage Heat Pump (Refer
to FM21 Instructions)]
					ALL JUMPERS
					REMOVED

terminal used only with heat pumps.

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CBWMV SERIES