normally to maintain proper unit operation. All normal cooling alarms and alerts are functional.

NOTE: Circuit A is always operated with Circuit B due to outdoor fan control on Circuit A. Always test Circuit A first, and leave it on to test other Circuits.

The Heating submenu is used to change output status for the individual heat stages, gas or electric. The fans and cooling service test outputs are reset to OFF for the heating service test. All normal heating alarms and alerts are functional.

Configuration

The RTU-MP controller configuration points affect the unit operation and/or control. Review and understand the meaning and purpose of each configuration point before changing it from the factory default value. The submenus containing configuration points are as follows: Unit, Cooling, Heating, Inputs, Economizer, IAQ, Clock-Set, and User Password (USERPW). Each configuration point is described below under its according submenu. See Form 48-50H-T-2T, Appendix for display tables.

Unit

Start Delay

This refers to the time delay the unit will wait after power up before it pursues any specific operation.

Factory Default = 5 sec Range = 0-600 sec

Filter Service Hours

This refers to the timer set for the Dirty Filter Alarm. After the number of runtime hours set on this point is exceeded the corresponding alarm will be generated, and must be manually cleared on the alarm reset screen after the maintenance has been completed. The timer will then begin counting its runtime again for the next maintenance interval.

Factory Default = 600 hr

NOTE: Setting this configuration timer to 0, disables the alarm.

Supply Fan Service Hours

This refers to the timer set for the Supply Fan Runtime Alarm. After the number of runtime hours set on this point is exceeded the corresponding alarm will be generated, and must be manually cleared on the alarm reset screen after the maintenance has been completed. The timer will then begin counting its runtime again for the next maintenance interval.

Factory Default = 0 hr

NOTE: Setting this configuration timer to 0, disables the alarm.

Compressor1 Service Hours

This refers to the timer set for the Compressor 1 Runtime Alarm. After the number of runtime hours set on this point is exceeded the corresponding alarm will be generated, and must be manually cleared on the alarm reset screen after the maintenance has been completed. The timer will then begin counting its runtime again for the next maintenance interval.

Factory Default = 0 hr

NOTE: Setting this configuration timer to 0, disables the alarm.

Compressor2 Service Hours

This refers to the timer set for the Compressor 2 Runtime Alarm. After the number of hours set on this point is exceeded the corresponding alarm will be generated, and must be manually cleared on the alarm rest screen after the maintenance has been completed. The timer will then begin counting its runtime again for the next maintenance interval

Factory Default = 0 hr

NOTE: Setting this configuration timer to 0, disables the alarm.

Cooling

Number of Compressor Stages

This refers to the number of mechanical cooling stages available on a specific unit. Set this point to “One Stage” if there is one compressor in the specific unit, set to “Two Stage” if there are two compressors in the unit, and set to “None” if economizer cooling ONLY is desired.

Factory Default = One Stage for 1 compressor units Two Stage for 2 compressor units

Cooling/Econ SAT Low Setpt

The supply air temperature must remain above this value to allow cooling with the economizer and/or compressors. There is 5_F plus and minus deadband to this point. If the SAT falls below this value during cooling, all compressors will be staged off. The economizer will start to ramp down to minimum position when the SAT = this configuration +5_F.

Factory Default = 50_F Range = 45-75_F

Cooling Lockout Temp

This defines the minimum outdoor air temperature that cooling mode can be enabled and run. If the OAT falls below this threshold during cooling, then compressor cooling will not be allowed.

Factory Default = 45_F Range = 0-65_F

Heating

Heating SAT High Setpt

The supply air temperature must remain below this value to allow heating. There is 5_F plus and minus deadband to this point. If the SAT rises above this value during heating the heat stages will begin to decrease until the SAT has dropped below this value.

Factory Default = 120_F Range = 95-150_F

Heating Lockout Temp

This defines the maximum outdoor air temperature that heating mode can be enabled and run. If the OAT rises above this threshold during heating, then heating will not be allowed.

Factory Default = 65_F Range = 49-95_F

48TC

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Carrier 48TCA04---A12 appendix Configuration
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48TCA04---A12 specifications

The Carrier 48TCA04---A12 is a high-efficiency rooftop air conditioning unit designed for commercial and industrial applications. Known for its reliability and performance, this model features advanced technologies that cater to diverse climate control needs.

One of the standout features of the Carrier 48TCA04---A12 is its excellent energy efficiency, which adheres to the stringent standards set by the U.S. Environmental Protection Agency. The unit utilizes a highly efficient scroll compressor combined with state-of-the-art heat exchanger technology, allowing it to operate with minimal energy consumption while providing powerful cooling capabilities.

The unit comes equipped with a robust and durable design, built to withstand various environmental conditions. Its weather-resistant cabinet is constructed from high-quality materials, ensuring long-lasting performance even in harsh climates. Additionally, the unit features a galvanized steel structure with a powder-coated finish, further enhancing its resistance to corrosion and wear.

In terms of technologies, the Carrier 48TCA04---A12 incorporates advanced controls that promote optimal performance. The unit supports Carrier's smart connectivity options, facilitating remote monitoring and adjustments via smart devices. This feature ensures convenient energy management and allows maintenance teams to access performance data, leading to proactive service interventions.

Another important characteristic of this unit is its quiet operation. The design includes sound-reducing insulation and a well-engineered airflow system, minimizing noise levels to create a more comfortable indoor environment. This is particularly important for commercial spaces such as offices and retail environments, where a tranquil atmosphere is critical for customer satisfaction and productivity.

The Carrier 48TCA04---A12 also offers diverse application flexibility, making it suitable for various locations, from small retail stores to large warehouses. With several tonnage options available, users can select a model that perfectly aligns with their specific cooling needs. Additionally, the unit can be easily integrated with existing HVAC systems, providing a seamless solution for upgrading or retrofitting older installations.

To sum up, the Carrier 48TCA04---A12 rooftop air conditioning unit stands out due to its exceptional energy efficiency, durable construction, advanced technology, and quiet operation, making it a reliable choice for commercial and industrial cooling solutions. Its flexibility and smart technology integrations ensure that it meets a wide range of climate control requirements effectively.
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