Heat Pump Controls

Each unit is factory provided with a Unit Protection Module (UPM) that controls compressor operation and monitors the safety controls that protect the unit. The UPM is a printed circuit board and is found in the heat pump module.

Safety controls include the following:

High pressure switch located in the refrigerant discharge line and wired across the HPC terminals on the UPM.

Low pressure switch located in the unit refrigerant suction line and wired across terminals LPC1 and LPC2 on the UPM.

The UPM includes the following features:

Anti-Short Cycle Timer

Five minute delay on break timer to prevent compressor short cycling.

Random Start

Each controller has a unique random start delay ranging from 270 to 300 seconds to reduce the chances

of multiple units simultaneously starting after initial power up or after a power interruption, creating a large electrical spike.

Low Pressure Bypass Timer

The low pressure switch is bypassed for 120 seconds after compressor start-up to prevent nuisance low pressure lockouts during cold start-up in the heating mode. If the low pressure switch remains opened after 120 seconds, the unit enters a soft lock.

Brownout/Surge/Power Interruption Protection The brownout protection in the UPM board will shut down the unit if the incoming power falls below 18 VAC. The unit will remain off until a minimal incoming power of 18 VAC is detected. Once proper power is restored, the unit will start-up within the random start time period.

Malfunction Output

The controller has a set of wet contacts for remote fault indication or dry contacts for communication with a DDC controller or BMS. The fault output will depend on the dip switch setting for “ALARM”. If set to “CONST”, a constant signal will be produced to indicate a fault has occurred and the unit requires inspection to determine the type of fault. If it is set to “PULSE”, a pulse signal is produced and a fault code is detected by a remote device indicating the fault. The remote device must have a malfunction detection capability when the UPM board is set to “PULSE”.

Test Dip Switch

A test dip switch is provided to reduce all time delay settings to five seconds during troubleshooting or verification of unit operation. Note that operation of the unit while in test mode can lead to accelerated wear and premature failure of the unit. The “TEST” switch must be set back to “NO” for normal operation.

Freeze Sensor

This is optional and can be set to ignore or monitor a freeze sensor. There are two configurable freeze points, 35°F and 15°F. The unit will enter a soft lockout until the temperature climbs above the set point and the anti- short cycle time delay has expired.

NOTE

If unit is employing a fresh water system (no anti- freeze protection), it is extremely important to have the “Freeze” switch set to 35°F in order to shutdown the unit at the appropriate leaving water temperature and protect your heat pump from freezing if a freeze sensor is included.

Crankcase Heater

A crankcase heater is installed around the base of each compressor in the unit to boil-off any liquid refrigerant that may be absorbed into the oil during idle periods. It is recommended the heater operate 24 hours prior to the compressors being started.

Model ERCH-HP Energy Recovery Unit 25

Page 25
Image 25
Greenheck Fan 473501 manual Heat Pump Controls

473501 specifications

Greenheck Fan 473501 is a significant player in the world of ventilation solutions, specifically designed to meet the increasing demands for efficiency and effectiveness in air movement. This commercial-grade fan is particularly noted for its high performance and reliability, making it a top choice for various applications, ranging from industrial settings to larger commercial spaces.

One of the main features of the Greenheck 473501 is its energy-efficient design. It is engineered to minimize energy consumption while maximizing airflow, allowing users to achieve optimal performance without incurring high utility bills. The fan is equipped with a powerful motor that not only ensures consistent airflow but also contributes to its overall longevity and durability.

The fan boasts an impressive air performance rating, which is crucial for environments that require precise temperature and humidity control. With adjustable airflow settings, users can customize the fan’s operation to suit specific needs, whether that means circulating air in a warehouse or exhaust in a manufacturing facility.

Another standout characteristic is the fan's robust construction. Built with corrosion-resistant materials, the Greenheck 473501 is ideal for use in harsh environments, where exposure to moisture and other elements could compromise lesser fans. The design also incorporates noise-reducing technologies, making it suitable for settings where quiet operation is essential, such as schools, hospitals, and office buildings.

In terms of installation, the Greenheck 473501 is designed for versatility. It can be easily integrated into various ventilation systems, whether for new constructions or upgrades to existing infrastructure. Its compact footprint allows for convenient placement without sacrificing performance.

Furthermore, Greenheck offers extensive support and resources for this model, ensuring users have access to the information necessary for optimal operation, maintenance, and any potential troubleshooting.

Overall, the Greenheck Fan 473501 represents a harmonious blend of efficiency, durability, and flexibility, making it an ideal choice for those seeking a high-quality ventilation solution that meets contemporary environmental standards while delivering reliable performance across diverse applications.