Alert Code A157 A/D Hardware Failure | Carrier 48/50PD05 specification

Carrier 48/50PD05 manual Alarm Code T155 Serial Eeprom Storage Failure Error, Alert Code T409

Recovery is automatic but MBB board replacement may be necessary. Cycling the power to the control should be tried before board replacement.

Alarm Code T155 - Serial EEPROM Storage Failure Error

Configuration data in the serial EEPROM chip can not be verified. The unit will run to last know good values or defaults, and therefore operating errors may occur. Recovery is automatic but MBB board replacement may be necessary. Cycling power to the control and reconfiguring the control points should be tried before board replacement.

Alarm Code A156 - Critical Serial EEPROM Storage Fail Error

The unit will completely shut down. Critical configuration data in the serial EEPROM chip can not be verified. Recovery is automatic but MBB board replacement may be necessary. Cycling power to the control and reconfiguring the critical control points should be tried before board replacement. There are no critical configurations in the 48/50PD.

Alert Code A157 - A/D Hardware Failure

The unit will completely shut down. The analog to digital conversion chip on the MBB has failed. Recovery is automatic but MBB board replacement may be necessary. Cycling power to the control should be tried before board replacement.

Alert Code A163 - Circuit A Down due to Failure

This alarm occurs when a circuit has 3 strikes. Use the Scrolling Marquee display to reset the alarm. Investigate the alarm that caused the strikes to occur.

Alert Code T178 - Loss of Communication with the Capacity Control Board

This alert occurs when the MBB cannot communicate with the AUX1 board. Unit operation will be disabled. This is usually caused by a wiring problem. Investigate using the Low Voltage Schematic, check that the AUX1 address is correct, and verify the resistance between pins on the LEN connections.

Alert Code T179 - Loss of Communication with the Economizer Control Board

This alert occurs when the MBB cannot communicate with the ECB. Economizer operation will be disabled. This is usually caused by a wiring problem. If a relative humidity sensor is installed and configured but there is not an ECB installed on the unit, this alert will be generated (the ECB is required for RH sensor operation). Investigate using the Low Voltage Schematic, check that the ECB address is correct, and verify the resistance between pins on the LEN connections.

Alert Code T180 - Loss of Communication with the Economizer Actuator

This alert occurs when the ECB cannot communicate with the Belimo Actuator. If the analog signal is connected properly, the economizer will still be controlled through it. This is usually caused by a wiring problem, actuator failure, or the wrong actuator. Investigate using the Low Voltage Schematic, make sure the actuator is a MFT communication actuator, and verify the feedback signal from the actuator is correct.

Alarm Code A200 - Linkage Timeout - Comm Failure

This alarm occurs when the MBB fails to communicate with a Linkage device. This only occurs when the MBB has previously communicated with a Linkage device since last power cycle. If a back up sensor was not installed the T074 alert will occur shortly after this one. Reset power to the unit and verify Linkage is communicating.

Alarm Code A404 - Fire Shutdown

This alarm occurs when the shutdown input is either open or closed depending upon its configuration. This alarm is usually caused by an auxiliary device that is trying to shut down the unit, e.g., smoke detector. The configuration for this switch input can be

found at variable Configuration→UNIT→FS.SW. Verify that the configuration is set correct, verify the wiring and auxiliary device. This alarm resets automatically.

Alert Code T408 - Dirty Air Filter

This alert occurs when the Filter Status switch senses a plugged filter for 120 continuous seconds after the indoor fan has been running for 10 seconds. Because the Dirty Air Filter switch can be configured normally opened or closed, the switch might be open or closed. The configuration for this switch input can be found at variable Configuration→UNIT→FL.SW. Verify that the configuration is set correct and verify the wiring and filter status switch. The hose should be connected to the low side of the switch. This alert resets automatically.

Alert Code T409

There are 2 different texts for this alert code. Pressing enter and esc on the marquee or navigator to expand the T409 alert will show you one of the below alerts. Make sure the expanded text is read correctly before troubleshooting.

SFan Status Switch On, Fan Contactor Off

This alarm occurs when the fan status switch has sensed that the indoor fan has been on for 10 seconds and the indoor fan feedback has determined that the indoor fan should be off. Because the Fan Status switch can be configured normally opened or closed, the switch might be open or closed. The configuration for this switch input can be found at Configuration→UNIT→FN.SW. Verify that the configuration is set correctly. Verify the wiring and fan status switch. The hose

should be connected to the high side of the switch. If the IDF is configured to shut down the unit when this alarm occurs

(Configuration→UNIT→IDF.F = YES), then this alarm can

only be reset manually and the unit is shut down. If the IDF is not configured to shut the unit down when this alarm occurs (IDF.F = NO), then this alarm resets automatically and no specific control action is taken.

SFan Status Switch Off, Fan Contactor On

This alert occurs when the fan status switch has sensed that the indoor fan has been off for 10 seconds and the indoor fan feedback has determined that the indoor fan should be on. Because the Fan Status switch can be configured normally opened or closed, the switch might be open or closed. The configuration for this switch input can be found at Configuration→UNIT→FN.SW. Verify that the configuration is set correctly. Verify the wiring and fan status switch. The hose should be connected to the high side of the switch. If the IDF is configured to shut down the unit down when this alert occurs (Configuration→UNIT→IDF.F = YES), then this alarm can only be reset manually and the unit is shut down. If the IDF is not configured to shut the unit down when this alert occurs (IDF.F = NO), then this alert resets automatically and no specific control action is taken.

Alert Code T414

There are 6 different alerts under this one alert code. Pressing enter and esc on the marquee or navigator to expand the T414 alert will show you one of the below alerts. All these alerts are generated by the Belimo actuator and reported to the ECB. These alerts can only occur if the ECB is controlling the actuator digitally through MFT.

SEconomizer Damper Actuator Out of Calibration

This alert occurs when the economizer actuator reports a control angle (Operating Modes→ECON→C.ANG) less than the minimum control angle (Configuration→ECON→M.ANG).

48/50PD

48/50PD05 specifications

The Carrier 48/50PD05 is a remarkable addition to Carrier's lineup of rooftop units, offering advanced cooling and heating solutions for commercial applications. Designed for medium-sized buildings, this unit is well-suited for both new installations and as a replacement for older systems, thanks to its versatile features and efficient performance.

One of the standout features of the 48/50PD05 is its energy efficiency. It incorporates state-of-the-art technology to achieve high Seasonal Energy Efficiency Ratios (SEER) and EER ratings, reducing operational costs while delivering superior comfort. The unit is also compliant with the latest energy regulations, making it an environmentally friendly choice for building owners concerned about sustainability.

The 48/50PD05 is equipped with a highly efficient scroll compressor, which not only enhances performance but also contributes to quiet operation. This is a significant advantage in commercial spaces where noise levels need to be kept in check for comfort and productivity. Additionally, the unit includes advanced airflow design, ensuring even distribution of conditioned air throughout the space.

Technologically, the Carrier 48/50PD05 features Carrier's Infinity Control system, which allows for precise control of indoor climate. This intelligent control mechanism can be integrated with smart building management systems, enabling users to monitor and manage energy use effectively. Wi-Fi connectivity is also available, providing remote access for real-time adjustments and diagnostics.

Durability is another characteristic of the 48/50PD05. Constructed with high-quality materials, the unit withstands various environmental conditions, ensuring longevity and reliability. Moreover, the modular design facilitates easy maintenance, making service procedures efficient and cost-effective.

In addition to cooling, the Carrier 48/50PD05 offers heating capabilities, often utilizing gas or electric heating options that can be tailored to the specific needs of a building. The unit can also be equipped with integrated economizers, allowing for free cooling during suitable outdoor conditions, further enhancing energy savings.

Overall, the Carrier 48/50PD05 stands out as a high-performance HVAC solution that combines efficiency, technology, and durability. It provides building owners with a versatile tool to ensure comfort while minimizing their environmental footprint. With a strong emphasis on energy savings and advanced control features, this rooftop unit is a smart investment for any commercial property.