Greenheck Fan ERVe manual Economizer Application/Operation, Modulating the Wheel, Controller

Page 12
Enthalpy
Sensor with
Override

Economizer Application/Operation

The energy recovery wheel operation can be altered to take advantage of economizer operation (free cooling). Two modes are available:

1.De-energizing the wheel

2.Modulating the wheel

A field supplied call for cool (Y1) is required.

De-energizing the wheel is accomplished with a signal from a Temperature or Enthalpy sensor mounted

in the air intake compartment. This primary sensor will de-energize the energy wheel when the outdoor air temperature (factory default is 65ºF) or enthalpy (factory default is the ‘D’ setting) is below the field adjustable set point. An Override temperature sensor is also furnished in the outdoor air intake compartment to deactivate economizer mode. The Override (with field adjustable set point) is set at some temperature lower than the primary sensor (factory default is 50ºF). Effectively, the two sensors create a deadband where the energy recovery wheel will not operate and free cooling from outside can be brought into the building unconditioned.

should not light and the energy recovery wheel should energize and rotate.

If these steps provide the results described, the enthalpy economizer is working properly.

•Turn unit power off. Reconnect C7400 Solid State

Enthalpy Sensor to terminal SO.

Modulating the Wheel

In applications in which an internal heat gain is present in the space, the rotational speed of the energy wheel may be modulated (via variable frequency drive) to avoid overheating the space during the winter. The speed of the energy wheel will be controlled in response to the discharge temperature set point.

Sequence of Operation: The variable frequency drive is fully programmed at the factory (refer to VFD section for more information). A “call for cool” must be field wired to the unit (terminals provided in unit - refer to wiring diagram in unit control center) to allow for initiation of economizer mode. When the space calls for cooling, factory supplied controls will drive the following wheel operations:

Testing

Temperature Sensor with Override

•Turn both Temperature and

Override thermostats down as low as they go. The wheel should be rotating.

•Turn the Temperature sensor up as high as it goes, and keep the Override sensor as low as it will go. The wheel should stop rotating.

Temperature

Sensor with

Override

TAO > TRA

Wheel runs at full speed.

(maximum energy recovery)

TAO < TRA

Wheel is stopped.

and

(no energy recovery)

TAO > TSA

 

TAO < TRA

Wheel will modulate to maintain

and

discharge temperature.

TAO < TSA

 

Where (TOA) is the outdoor air temperature set point, (TRA) is the return air temperature set point, and (TSA)

•Turn both sensors as high as they will go. The wheel should start rotating.

•Set the Temperature sensor at desired point for economizer operation to begin. Set the Override sensor at desired point for economizer operation to end (factory default is 65ºF and 50ºF, respectively).

Enthalpy Sensor with Override

•Turn unit power off. Disconnect

C7400 Solid State Enthalpy Sensor from terminal So on the enthalpy controller. Also, disconnect the

620 ohm resistor from

terminal Sr on the enthalpy controller. Turn unit power on. The LED on the enthalpy

controller should light and the energy recovery wheel should not rotate.

•Turn unit power off. Reconnect 620 ohm resistor to terminal Sr on the

enthalpy controller. Turn unit power Enthalpy on. The LED on the enthalpy controller

Controller

12Model ERVe Energy Recovery Unit

is the supply air discharge thermostat set point.

Page 11 Page 13
Image 12
Page 11 Page 13
Contents Installation, Operation and Maintenance Manual Model ERVe General Safety InformationInspection and Maintenance during Storage ReceivingUnpacking HandlingTable of Contents Supplemental Installation Operation and Maintenance ManualsInstallation Basic OperationRoof Curb and Rail Mounting Lifting with a CraneLifting with a Forklift Recommended Roof OpeningCurb Outside Dimensions and Weights Roof Curb MountingDuctwork Connections Service Clearances Access Panel Description and LocationRail Mounting / Layout Dimensional Data Duct Dimensions Unit SizeElectrical Information Typical Control Center Components Electric Heater Application/OperationUnit Accessories Outdoor Air WeatherhoodExhaust Weatherhood DampersOptional Accessories Frost Control Application/OperationTesting Temperature Sensor with Override Economizer Application/OperationModulating the Wheel Enthalpy Sensor with OverrideVariable Frequency Drives for Energy Recovery Blowers Factory Set PointsDrive Operation Variable Frequency Drives for Energy Recovery Wheel Economizer Signal Source10 VDC Typical Wiring Diagram TransformerService Outlet Rotation SensorDirty Filter Sensor CO2 SensorRemote Control Panel and Wiring Schematics Indicator Lights powered by the ER UnitDay Timer or On/Off Switch Dirty Filter Indicator power by othersTemperature Sensors 1K Ohm RTD Sensors Mounted by FactoryPressure Sensors analog or digital Amp Current Sensors analog or digitalPre Start-Up Checklist check as items are Start-Up ChecklistStart-Up General Start-Up InformationOptional Accessories Checklist Optional Accessories sectionEconomizer Application / Operation section Variable Frequency Drives sectionUnit Start-Up Energy Recovery Wheel VibrationDrive Belt Air SealsRoutine Maintenance Maintenance Procedures LubricationFan Belts Fan MotorsExternal Filter Maintenance Internal Filter MaintenanceDoor Seal Maintenance Fan Wheel & FastenersEnergy Recovery Wheel Maintenance Parts List Sequence of OperationTroubleshooting Airflow Troubleshooting Unit Symptom Possible Cause Corrective ActionTroubleshooting Unit Maintenance Log Model ERVe Energy Recovery Unit Warranty

ERVe specifications

The Greenheck Fan ERVe series stands at the forefront of energy-efficient ventilation solutions, specifically designed to meet the growing demands for energy conservation and enhanced indoor air quality in commercial buildings. As part of Greenheck's commitment to innovation, the ERVe series offers a variety of models tailored to diverse applications, including schools, hospitals, and office buildings.

One of the key features of the ERVe series is its advanced energy recovery technology. The ERVe utilizes a heat recovery wheel that efficiently transfers heat and moisture between the exhaust and incoming airstreams. This process significantly reduces heating and cooling loads on HVAC systems, promoting energy savings and improving overall system efficiency. By reclaiming energy that would otherwise be wasted, the ERVe ensures that buildings not only conform to energy codes but also contribute to sustainability goals.

The ERVe series is designed with versatility in mind. It offers multiple configurations, including vertical and horizontal orientations, which makes it adaptable to various installation environments. Additionally, the unit can be equipped with a range of options such as pre-filters, post-filters, and variable speed drive motors, allowing for customization based on specific application needs. This adaptability ensures that the ERVe can meet the specific air quality requirements of different spaces while maintaining optimal airflow.

Another significant characteristic of the ERVe series is its low noise operation. The design incorporates advanced acoustical features, including sound attenuators and insulated panels, which minimize sound transmission and enhance occupant comfort. As noise control becomes increasingly important in settings like educational institutions and healthcare facilities, the ERVe series excels in providing a peaceful indoor environment.

Moreover, the ERVe series is engineered with durability in mind. Constructed from high-quality materials, the units are built to withstand the rigors of continuous operation. The robust design not only extends the service life of the equipment but also reduces maintenance requirements, leading to lower overall operational costs.

In terms of control and monitoring, the ERVe series is compatible with various building management systems, allowing for integration into sophisticated HVAC controls. This feature enables real-time data tracking and optimization, enhancing the efficiency of indoor climate management.

Overall, the Greenheck Fan ERVe series represents a significant advancement in ventilation technology, combining energy efficiency, customizable features, low noise operation, and durability. These characteristics ensure that the ERVe is a reliable choice for modern commercial buildings striving for improved air quality and reduced energy consumption.
Top Page Image Contents