Freezestat Operation

IMPORTANT

Use of the freezestat feature is required in all instal- lations using CBWMV units.

The CBWMV unit is equipped with a field-wired freezestat. The freezestat protects the CBWMV system from freezing temperatures when the unit is installed in unconditioned areas.

The factory-provided freezestat must energize the circula- tor when water temperatures fall below 45ºF. Freezestat wiring is shown in figure 13.

Freezestat Field Wiring

Figure 13

BDC3 Variable Blower Control Board

CBWMV units are equipped with a variable speed motor that is capable of maintaining a specified CFM throughout the external static range. A particular CFM can be obtained by positioning jumpers (COOL, HEAT, and ADJUST) on the BDC3 control board. The COOL and HEAT jumpers are labeled 1, 2, 3, and 4. Each of the numbers corre- sponds with an air volume (CFM) setting. The ADJUST jumper is labeled TEST, −, +, and NORM. The + and − pin settings are used to add or subtract a percentage of the CFM selected. The TEST jumper is used to operate the motor in the test mode. The DELAY jumper controls ramp- ing profiles.

Figure 14 shows the BDC3 control board. Use tables 5 through 9 to determine the correct air volume for heat and cool speed taps.

Diagnostic LEDs located on the BDC3 control board are provided to aid in identifying the unit’s mode of operation. Certain scenarios will arise depending on the jumper posi- tions. Read through the jumper settings sections before adjusting blower speed. Refer to figure 14 for identification.

Continuous Low Blower Option

Refer to the blower speed chart located on the CBWMV unit wiring diagram for factory set cooling, heating and low (continuous) blower speeds. Systems using a cooling ther- mostat subbase may operate continuous blower (factory- set to operate at 38% of second-stage cooling speed) through the FAN−ON switch of the thermostat. For continu- ous low blower with a system without a cooling subbase, a fan switching subbase may be used.

Heating or cooling demand will cause blower to go to heat or cool speed.

Blower Speed Adjustments

Diagnostic LEDs

RUN LED Indicates a demand for blower operation in either the heating mode or continuous fan−only mode. RUN LED will not illuminate during a cooling demand.

CFM LED Indicates the CFM at which the unit is operat- ing. The light flashes once for approximately every 100 CFM. For example, if the unit is operating at 1000 CFM, CFM LED will flash 10 times. If the CFM is 1150, CFM LED will flash 11 full times plus one fast or half flash.

At times the light may appear to flicker or glow. This takes place when the control is communicating with the motor between cycles. This is normal operation.

The appropriate speed according to application and CFM need is selected by moving jumper pins.

BDC3 Variable Speed Control Board

JP1 15 PIN PLUG (BOARD TO MOTOR)

ACCESSORY RELAY CON- TACTS (DRIVES OP-

TIONAL ACCESSORY RELAY)

OPERATIONAL SELECTOR PINS (AFFECTS BOTH HEATING AND COOLING MODES)

HEATING SPEED	COOLING SPEED	FAN DELAY	DIAGNOSTIC
SELECTOR PINS	SELECTOR PINS	SELECTOR PINS	LEDS

Figure 14

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CBWMV, AIR HANDLERS specifications

Lennox International Inc is a renowned leader in the heating, ventilation, and air conditioning (HVAC) industry, known for its commitment to innovation and energy efficiency. Among its impressive lineup of products, the CBWMV air handlers stand out as a reliable solution for optimal indoor climate control.

The CBWMV air handler is designed to provide efficient and effective airflow while being easy to install and maintain. One of the key features of the CBWMV model is its variable speed blower motor, which allows for precise control of airflow and temperature. This innovation not only enhances comfort levels within a space but also contributes to significant energy savings. By adjusting the speed of the motor according to the heating or cooling demand, the system operates more efficiently, reducing energy usage by up to 40% compared to conventional systems.

Another important characteristic of the CBWMV air handlers is their compatibility with a range of heating and cooling systems, including heat pumps and gas furnaces. This versatility makes them an ideal choice for residential and commercial applications alike. The unit’s compact design allows for flexible installation options, accommodating various spaces without compromising performance.

The CBWMV series is also engineered to provide superior air quality. With advanced filtration options, these air handlers can effectively remove dust, allergens, and pollutants from the air, promoting a healthier indoor environment. Many models come equipped with a MERV 16 filter, enhancing the filtration capability, and ensuring that occupants breathe cleaner air.

Durability is another hallmark of the CBWMV line. Constructed with high-quality materials, these air handlers can withstand rigorous use and environmental conditions. The units are designed to require minimal maintenance, with features that facilitate easy access for filter changes and routine servicing.

Additionally, the CBWMV series integrates seamlessly with Lennox’s smart technology solutions, allowing users to monitor and control their HVAC systems remotely. The compatibility with home automation systems ensures that users can optimize comfort settings and efficiency with ease.

In conclusion, Lennox International Inc's CBWMV air handlers offer a remarkable blend of efficiency, comfort, and innovative technology. With features that prioritize energy savings, air quality, versatility, and durability, they represent a forward-thinking choice for modern HVAC needs. Whether for residential or commercial use, these air handlers stand as a testament to Lennox's commitment to excellence in indoor climate management.

Lennox International Inc AIR HANDLERS Freezestat Operation, BDC3 Variable Blower Control Board

Models: CBWMV AIR HANDLERS