DISCRETE OUTPUT/ANALOG INPUT CONTROL Ð The discrete output is controlled as a function of a temperature sensor connected to the 39L or 39NX unit. (Applicable sen- sors are: space temperature sensor, outside-air temperature sensor, mixed-air temperature sensor, supply-air tempera- ture sensor, and return-air temperature sensor.) The discrete output is turned ON/OFF as required to maintain the user con®gured set point.

The controlling sensor is identi®ed and its value is read. The control determines which user-con®gurable control logic (normal or reverse) is required.

The control compares the sensor value to the con®gured set point.

If normal logic is used, the discrete output is turned ON when the sensor value is equal to or greater than the set point. This output is turned OFF when the sensor value is less than the set point decreased by a user con®gurable hysteresis.

If reverse logic is used, the discrete output is turned ON whenever the sensor value is less than the set point. This output is turned OFF when the sensor value is greater than the set point increased by a user con®gurable hysteresis.

DISCRETE OUTPUT, TIMECLOCK CONTROL Ð This control sequence turns ON an output channel when the cur- rent time of day is greater than or equal to the Occupied time and less than the next Unoccupied time. This discrete output is OFF at all other times. The output can be used for lighting control, pump control, or to control other devices which have to be ON during the Occupied period and OFF during the Unoccupied period. This control sequence operates under its own time schedule (Schedule II).

Using the local interface device or building supervisor, the output may be overridden to extend the occupied period be- tween 1 and 4 hours.

The control determines the output that is under time- clock control. The current time of day is compared to the Occupied time and to the next Unoccupied time. If the current time of day is equal to or within the Occupied time period, the discrete output is turned ON. If the current time of day is equal to or within the Unoccupied time period, the discrete output is turned OFF.

HUMIDITY (ANALOG OUTPUT) CONTROL Ð The hu- midity analog output control adjusts the steam valve of the steam grid humidi®er. The valve is modulated to maintain the desired space or desired return-air humidity set point, depending on whether a wall-mounted or duct-mounted hu- midity sensor is used. A duct high humidity switch is also monitored and provides a user adjustable high limit safety.

If the supply fan is OFF, the steam valve is held closed.

If the supply fan is ON, and the unit is in the Unoccupied mode, the valve is held closed.

If the supply fan is ON and the unit is in the Occupied mode, the system determines the status of the duct high hu- midity switch. If the duct humidity is above the switch set point, the valve is held closed. If the duct humidity is less than the switch set point, the control reads the humidity sen- sor, compares the value to the set point and modulates the output as required to satisfy conditions.

HUMIDITY (DISCRETE OUTPUT) CONTROL Ð The hu- midity control sequentially adjusts a 2-stage humidi®er. The humidi®er is controlled to maintain a desired space or return- air humidity, depending on whether a wall-mounted or duct- mounted humidity transmitter is used.

The ®rst stage of humidi®cation energizes the humidi®er spray pump (if applicable) along with the ®rst stage of the humidi®er. The second stage of humidi®cation energizes the second stage of the humidi®er.

A duct high humidity switch is also monitored and pro- vides a user adjustable duct high humidity limit safety.

If the fan status is ON and the unit is in the Occupied mode, the control reads the space or return-air humidity sen- sor. If the humidity is 2% less than the humidity set point, the ®rst stage is turned ON.

If the humidity is 5% less than the humidity set point, both stages are turned ON.

As the humidity increases, the stages are turned OFF as follows: When the humidity is within 2% of the set point, the second stage of the humidi®er is turned OFF. When the humidity is greater than or equal to the set point, both stages are turned OFF. If the high humidity switch is tripped, all stages of the humidi®er are turned OFF.

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Carrier 39L specifications

39L specifications

The Carrier 39L is a cutting-edge air conditioning unit designed for both residential and commercial applications, providing exceptional cooling and heating performance. Equipped with advanced technologies, this system ensures optimal climate control while maintaining energy efficiency.

One of the standout features of the Carrier 39L is its inverter technology. This innovation allows the system to adjust its compressor speed based on the ambient temperature, which results in a significant reduction in energy consumption. By operating at varying capacities rather than a fixed output, the 39L can maintain a consistent temperature, enhancing comfort while lowering electricity bills.

The Carrier 39L also includes a high-efficiency air filtration system, designed to capture dust, allergens, and other airborne particles. This not only improves indoor air quality but also promotes a healthier living environment. The filtration system is complemented by anti-bacterial treatment, ensuring that the air circulated within your space is both clean and refreshing.

In terms of design, the Carrier 39L boasts a sleek and compact form factor, making it easy to integrate into various settings, from homes to offices. Its quiet operation is another notable feature, as it minimizes noise levels, allowing occupants to enjoy a serene atmosphere without disruptive sound.

Further enhancing convenience, the Carrier 39L comes equipped with smart connectivity options. Users can control the unit remotely via a smartphone app, making it easy to adjust settings, program schedules, and monitor energy usage from anywhere. This feature not only improves user experience but also supports energy-saving practices.

Durability is also a key characteristic of the Carrier 39L. Constructed with high-quality materials and coated with corrosion-resistant treatments, the unit is built to withstand various environmental conditions. This ensures long-lasting performance and reduces the need for frequent maintenance.

Overall, the Carrier 39L is a versatile, efficient, and user-friendly air conditioning solution. Its blend of advanced technologies, energy-saving capabilities, and robust design makes it an ideal choice for those seeking reliable climate control in their spaces. Whether for residential comfort or commercial necessity, the Carrier 39L stands out as a leader in modern air conditioning.