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Installation, Operation and Maintenance Manual
Please read and save these instructions. Read carefully before attempting to assemble, install, operate or maintain the
product described. Protect yourself and others by observing all safety information. Failure to comply with instructions
could result in personal injury and/or property damage! Retain instructions for future reference.
Model RT
General Safety Information
Only qualified personnel should install this system.
Personnel should have a clear understanding of these
instructions and should be aware of general safety
precautions. Improper installation can result in electric
shock, possible injury due to coming in contact with
moving parts, as well as other potential hazards,
including environmental. Other considerations may be
required if high winds or seismic activity are present.
If more information is needed, contact a licensed
professional engineer before moving forward.
1. Follow all local electrical and safety codes, as well
as the National Electrical Code (NEC), the National
Fire Protection Agency (NFPA), where applicable.
Follow the Canadian Electric Code (CEC) in
Canada.
2. All moving parts must be free to rotate without
striking or rubbing any stationary objects.
3. Unit must be securely and adequately grounded.
4. Do not spin fan wheel faster than maximum
cataloged fan RPM. Adjustments to fan speed
significantly effects motor load. If the fan RPM is
changed, the motor current should be checked to
make sure it is not exceeding the motor nameplate
amps.
5. Do not allow the power cable to kink or come in
contact with oil, grease, hot surfaces or chemicals.
Replace cord immediately if damaged.
1
Model RT
Energy Recovery Ventilators
6. Verify that the power source is compatible with the
equipment.
7. Never open access doors to the unit while it is
running.
DANGER
• Always disconnect power before working on or
near this equipment. Lock and tag the disconnect
switch or breaker to prevent accidental power up.
• If this unit is equipped with optional gas
accessories, turn off gas supply whenever power
is disconnected.
CAUTION
This unit is equipped with a compressed refrigerant
system. If a leak in the system should occur,
immediately evacuate and ventilate the area. An
EPA Certified Technician must be engaged to make
repairs or corrections. Refrigerant leaks may also
cause bodily harm.
CAUTION
When servicing the unit, the internal components
may be hot enough to cause pain or injury. Allow
time for cooling before servicing.
Part #970-458
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Summary of Contents for Bosch FHP RT-20
- Page 1 Part #970-458 Energy Recovery Ventilators Installation, Operation and Maintenance Manual Please read and save these instructions. Read carefully before attempting to assemble, install, operate or maintain the product described. Protect yourself and others by observing all safety information. Failure to comply with instructions could result in personal injury and/or property damage! Retain instructions for future reference.
- Page 2 Receiving/Inspection Machined parts coated with rust preventive should be restored to good condition promptly if signs of Upon receiving the product, check to make sure rust occur. Immediately remove the original rust all items are accounted for by referencing the bill preventive coating with petroleum solvent and clean of lading to ensure all items were received.
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Page 3: Table Of Contents
Table of Contents General Description....4 Rotation Sensor ....28 Models and Capacities . -
Page 4: General Description
General Description Models and Capacities The RT brings in fresh, outdoor air and removes The RT is manufactured in four different platform stale exhaust air from the building. The intake and sizes; 20, 45, 55 and 90. Each platform has multiple exhaust airstreams move through the RT in opposite options for heating and cooling capacities. -
Page 5: Owners Information
Owner’s Information RT Dampers There are four locations where dampers are optionally The following summary highlights some important installed. If an exhaust weatherhood is installed, a notes to help avoid premature failure and possible gravity type damper is included with that fixture. voidance of warranty. -
Page 6: Filters
RT Filters RT Heat Pump Module There are three locations in the RT where filters will be Every RT has an integral heat pump module that found. In the Outdoor Air Intake, there are permanent contains hermetic scroll-type compressor(s), a coaxial metal filters that are accessed by removing the filter refrigerant-to-water heat exchanger(s), refrigerant flow access panel on the side of the louver assembly. -
Page 7: Optional Electric Heaters
RT Optional Electric Heaters RT Optional Indirect Gas Furnace There are two optional electric heaters available for An optional Indirect Gas furnace may be installed in the RT. One is a preheater and is used to prevent the RT and its function is to provide supplementary frost buildup on the energy wheel. -
Page 8: Operating Concerns
Operating Concerns IMPORTANT Do not release refrigerant to the atmosphere! If Low Ambient Operation required service procedures include the adding or Care has been taken to ensure low ambient operation removing of refrigerant, the service technician must does not cause damage to the refrigerant system. A comply with all federal, state and local laws. -
Page 9: Installation
Installation Concerns Unit Weights and Recommended Roof Opening The RT will most often be installed on a rooftop but in some cases it may be preferable to install the unit at ground level beside the building, or even indoors. This portion of the IOM applies directly to roof top installations but most of the concerns remain the same regardless of where the unit is installed. -
Page 10: Dimensional Data
Dimensional Data Overall Exterior Dimensions Model Width Overall Width Overall Length (including Lifting Lugs) (with Exhaust Hood) (with Outdoor Air Hood) RT-20 59.5 RT-45 69.5 RT-55 79.5 RT-90 99.5 All dimensions shown are in inches. Access Door Description and Location Following is a list of items accessible through the access doors shown on the diagrams. -
Page 11: Service Clearances
Service Clearances RT-20, -45, -55, and -90 units require minimum clearances for access on all sides for routine maintenance. Filter replacement, drain pan inspection and cleaning, energy wheel cassette inspection, fan bearing lubrication and belt adjustment are examples of routine maintenance that must be performed. Blower and motor assemblies, energy wheel cassette, coil and filter sections are always provided with a service door or panel for proper component access. -
Page 12: Handling And Lifting
Handling Lifting While this unit was constructed with quality and 1. Before lifting, be sure that all shipping material dependability in mind, damage still may occur during has been removed from unit. handling of the unit for installation. Exercise extreme 2. -
Page 13: Roof Curb Mounting / Dimensions / Weights
Roof Curb Mounting Curb Outside Dimensions and Weights Rooftop units require curbs to be mounted first. The duct connections must be located so they will be SIDE OF UNIT clear of structural members of the building. BASE 1 Factory Supplied Roof Curbs: Roof curbs are Model GKD, which are shipped in a knockdown kit (includes duct adapter) and require field assembly (by others). -
Page 14: Vibration Isolators
Vibration Isolators NOTE NOTE On some models of the RT, one lifting lug may be positioned directly in front of the condensate drain Many motor / blower assemblies include optional connection. See illustration. spring vibration isolation devices. When these isolation springs are used, the motor / blower assembly is secured for shipment by compressing the springs and securing the assembly to intermediate rails (see photo). -
Page 15: Drain Trap
Drain Trap The RT is equipped with a stainless steel condensate pan with a stainless steel drain connection. It is important that the drain connection be fitted with a P trap to ensure proper drainage of the RT while maintaining internal static pressures and to prevent migration of sewer gas back into the unit. -
Page 16: Plumbing
Plumbing 4. Water coils are not normally recommended for use with entering air temperatures below 40ºF; however, the energy wheel maintains a pre-coil Coil Application Recommendations temperature higher than 40ºF. No control system Factory installed cooling and heating components can be depended on to be 100% safe against are mounted in the coil section of the unit. -
Page 17: Electrical Information
Electrical Information Voltage Supply: See voltage use range on the rating plate. Measure and record each supply leg voltage at Warning: DO NOT penetrate the roof of the unit for all line disconnect switches. Readings must fall within any reason since there are hazardous voltage circuits the allowable range on the rating plate. -
Page 18: Control Center Components
Typical Control Center Components - individual components and locations will vary 1. Main Disconnect (non-fusible, 10. Compressor fuse blocks 18. Economizer module lockable) 11. Compressor contactors 19. Thermostats for: 2. Motor Starter - Exhaust Air Fan 12. Condensing fan contactors - Economizer module 3. -
Page 19: Optional Preheater
Optional Accessories Electric Heater Application/Operation Factory installed electric heaters may be optionally Preheaters: Preheaters are standard as two-stage, supplied for energy wheel preheating. The optional step control. Step control heaters are designed with electric preheater is positioned upstream of the air multiple stages made up of equal increments of intake filters and its primary function is to prevent heating capability. -
Page 20: Typical Wiring Diagram
Typical Wiring Diagram Following is an example of a typical wiring diagram located in the unit control center. This wiring diagram includes a legend highlighting which accessories were provided with the unit. Factory wiring and field wiring are also indicated. This particular example includes 1) variable frequency drives on the blowers requiring a modulating input, 2) modulating energy recovery wheel with factory controls for economizer, 3) energy wheel rotation sensor, 4) outdoor air and exhaust air dirty filter switches, 5) motorized outdoor air and exhaust air intake dampers, and 6) timed exhaust frost control. -
Page 21: Microprocessor Controller Sequence Of Operation
Microprocessor Controller • Unoccupied mode (Cycle on Room) Optional unoccupied mode when there is a Sequence of Operation recirculation damper and a room temperature sensor wired to unit. Microprocessor Controller 1. Exhaust fan off This unit is typically provided with a microprocessor 2. - Page 22 Heating Sequence The heating is controlled to maintain the supply temperature set point. The heating will be locked out when the outside air is > 70°F + 2°F hysteresis, adjustable. • Water Source Heat Pump Heating: DDC will provide a digital signal for 1 or 2 stages of heating to maintain the supply air set point (adjustable).
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Page 23: Energy Wheel Sequence Of Operation
Energy Wheel Sequence of Optional Accessories Operation The following accessories can be ordered with the unit to expand the functionality or usability of the Optional Economizer controller. • Stop Wheel: When economizer mode is enabled • Room Temperature Sensor (TS): The room and there is a signal for cooling, the wheel will temperature sensor is a field mounted sensor stop rotating to allow free cooling. -
Page 24: Frost Control Application/Operation
Frost Control Application/Operation • Turn the temperature sensor up as high as possible. The supply blower should cycle on for Extremely cold outdoor air temperatures can cause one minute, then turn off for one minute. moisture condensation and frosting on the enthalpy wheel. -
Page 25: Economizer Application / Operation
Economizer Application / Operation Enthalpy Sensor with Override The energy wheel operation can be altered to take • Turn unit power off. advantage of economizer operation (free cooling). Disconnect C7400 solid Two modes are available: 1) De-energizing the wheel state enthalpy sensor or 2) Modulating the wheel. -
Page 26: Variable Frequency Drive (Vfd)
Variable Frequency Drives (VFD) An optional VFD may be installed at the factory for purposes of controlling the speed of the energy wheel or the blower motors. Its purpose is to constantly regulate the speed of rotation of the energy wheel or the blower motors in response to various optional sensors. -
Page 27: Optional Remote Control Panel And Schematics
Remote Control Panel and Wiring Indicator Lights powered by the ER Unit Schematics The remote panel is a series of junction boxes ganged together and includes a stainless steel faceplate. The remote panel is available with a number of different Unit On/Off alarm lights and switches to control the unit. -
Page 28: Rotation Sensor
Rotation Sensor Microprocessor (DDC) Temperature Control Package The rotation sensor monitors energy wheel rotation. If the wheel should stop rotating, the sensor will The RT may be controlled either by owner-supplied close a set of contacts in the unit control center. Field and installed controlling devices or it may be wiring of a light (or other alarm) between terminals R optionally equipped with a microprocessor (DDC) -
Page 29: Sensor Schematic
Sensors Mounted by Factory Factory mounted temperature, pressure, and current sensors are available in the locations indicated on the unit diagram below. A list of available sensors is shown below. The specific sensors provided on a given unit are labeled in the unit control center on the terminal strip. Sensors are wired to the terminal strip to make it easy for the controls contractor to connect the Building Management System for monitoring purposes. - Page 30 Optional Field-Installed Control Sensors Microprocessor (DDC) Remote Interface The following sensors and control devices are all The optional Remote Interface Panel permits viewing options that may be ordered with the RT. They are of settings that are present on the microprocessor shipped loose with the unit and are to be field- controller (DDC) and also permits inputting of new installed in a location selected by the A / E or the...
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Page 31: Heat Pump Overview
Heat Pump Overview High Temp Protection - internal devices within the compressor protect it against excessively high Every RT has a complete, sealed refrigeration system discharge gas temperatures (only on compressors that is ready for connection to a water source. above 6 hp) The heat pump has all the typical DX components Crankcase Heater - liquid refrigerant is... -
Page 32: Heat Pump Controls
Heat Pump Controls to “CONST”, a constant signal will be produced to indicate a fault has occurred and the unit requires Each unit is factory provided with a Unit Protection inspection to determine the type of fault. If it is set to Module (UPM) that controls compressor operation “PULSE”, a pulse signal is produced and a fault code and monitors the safety controls that protect the unit. -
Page 33: Heat Pump Fault Indicators
Unit Protection Module (UPM) Fault Lockout Reset A hard lockout can be reset by turning the unit Indications thermostat off and then back on when the “RESET” dip switch is set to “Y” or by shutting off unit power Each RT will have one Unit Protection Module printed at the circuit breaker when the “RESET”... -
Page 34: Energy Recovery Wheel
Energy Recovery Wheel The RT models contain a total energy recovery wheel. The wheels are inspected for proper mechanical operation at the factory. However, during shipping and handling, shifting can occur that may affect wheel operation. The wheel is accessible through the access door marked “Energy Wheel Cassette Access”. -
Page 35: Refrigeration Schematic
Refrigeration System Schematic Typical Operating Conditions Location Refrigerant State Temperature Pressure Superheat/Subcool Before water-to-refrigerant Hot Vapor 150°F 330 psig 50°F Superheat heat exchanger Cooling After water-to-refrigerant Warm Liquid 85°F 330 psig 15°F Subcool Mode / heat exchanger Refrigerant After Thermostatic Saturated Liquid- Properties 45°F... -
Page 36: Compressor
Start-Up General Start-Up Information Every installation requires a comprehensive start- up to ensure proper operation of the unit. As part DANGER of that process, the following checklist must be Electric shock hazard. Can cause injury or death. completed and information recorded. Starting up Before attempting to perform any service or the unit in accordance with this checklist will not maintenance, turn the electrical power to unit... - Page 37 o Verify diameter seal settings on the energy After the entire unit has been installed and inspected recovery wheel (refer to Start-Up section for more for completeness, any jumper or other controller on information). terminals R and G on the terminal strip should be disconnected to prevent accidental startup.
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Page 38: Return Air Temperature
14. At this time, verify that both compressors are • Compressor running and record intake and discharge water _______ L1 amps temperatures. Record the results on the Start-Up _______ L2 amps Checklist. _______ L3 amps _______ Crankcase Heater If only the lead compressor is running, force the second compressor into operation by temporarily Outdoor Air Temperature installing jumpers on the terminal strip from R to... - Page 39 Optional Accessories Checklist Refer to the respective sections in this Installation, Operation and Maintenance Manual for detailed information. Refer to wiring diagram in unit control center to determine what electrical accessories were provided. Provided with Unit? Frost Control Application / Operation section: Setting Factory Default Frost Control set point...
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Page 40: Troubleshooting Airflow
Troubleshooting – Airflow Test and Balance Report The Test and Balance Report (TAB) is utilized to determine whether the appropriate amount of outdoor air and exhaust air is being supplied and removed from a building, respectively. There are no set rules on what information must be included in a TAB report. - Page 41 Troubleshooting – Unit Symptom Possible Cause Corrective Action Replace fuse or reset circuit breaker and check Blown fuse or open circuit breaker. amps. Defective motor or capacitor. Replace. Blower fails to Motor starter overloaded. Reset starter and check amps. operate Check for On/Off switches.
- Page 42 Troubleshooting – Unit Symptom Possible Cause Corrective Action Adjust wheel and/or inlet cone. Tighten wheel Fan wheel rubbing on inlet. hub or bearing collars on shaft. Replace defective bearing(s). Lubricate bearings. Bearings. Tighten collars and fasteners. Wheel out of balance. Replace or rebalance.
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Page 43: Refrigeration Circuit
Troubleshooting – Refrigeration Circuit TROUBLESHOOTING NOTE IMPORTANT Do not release refrigerant to the atmosphere! If Before any components are changed on the required service procedures include the adding or refrigeration system, the cause of the failure must be removing of refrigerant, the service technician must identified. - Page 44 Troubleshooting – Refrigeration Circuit Symptom Possible Cause Corrective Action Refrigerant overcharge. Check pressures, charge by subcooling. In cooling mode low water flow rate. Increase water flow rate. Compressor starts In heating mode low air flow over air coil. Change filter or clean air coil. but cuts out on high pressure switch Check high side equalized pressure reading with...
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Page 45: Superheat
Troubleshooting – Refrigeration Circuit Symptom Possible Cause Corrective Action Refrigerant overcharge. Check pressures and subcooling. Check thermal expansion valve setting. Check for Liquid floodback. refrigerant overcharge. Dampen tubing vibration by taping or clamping. Tubing rattle. Carefully bend tubing away from contact where Compressor noisy possible. - Page 46 Troubleshooting – Refrigeration Circuit Symptom Possible Cause Corrective Action Refrigerant undercharge. Check pressures and subcooling. Interchange any two wires from 3 phase Blower running backward. disconnect. Loose blower, pulley or belts. Check drive pulley alignment, belt tension. Low entering air temperature (low load Check entering air wet bulb conditions.
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Page 47: Suction Line Pressure
Troubleshooting – Refrigeration Circuit Symptom Possible Cause Corrective Action Check system for leaks. Repair leaks and add Refrigerant leak. refrigerant. Short cycling. Check low pressure control settings. Compressor Check thermal expansion valve setting. Check for Refrigerant flood back. loses oil refrigerant overcharge. -
Page 48: Maintenance Overview
Routine Maintenance 3. Motors Check for cleanliness 4. Fan Belts DANGER Check for wear, tension, alignment Electric shock hazard. Can cause injury or death. 5. Blower Wheel & Fasteners Before attempting to perform any service or Check for cleanliness maintenance, turn the electrical power to unit Check all fasteners for tightness to OFF at disconnect switch(es). - Page 49 Fan Bearings When replacing belts on multiple groove drives, all belts should be changed to provide uniform drive Most bearings are permanently lubricated and require loading. Do not pry belts on or off the sheave. Loosen no further lubrication under normal use. Normal use belt tension until belts can be removed by simply being considered -20ºF to 120ºF and in a relatively lifting the belts off the sheaves.
- Page 50 Internal Filter Maintenance Coil Maintenance The RT units will typically be provided with 2-inch, Coils must be cleaned to obtain maximum pleated filters in the supply airstream. These filters performance. Check once a year under normal should be checked per a routine maintenance operating conditions and if dirty, brush or vacuum schedule and replaced as necessary to ensure proper clean.
- Page 51 Maintenance Log Date __________________ Time _____________ AM/PM Date __________________ Time _____________ AM/PM Notes:___________________________________________ Notes:___________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ Date __________________ Time _____________ AM/PM Date __________________ Time _____________ AM/PM Notes:___________________________________________ Notes:___________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ _________________________________________________ Date __________________ Time _____________ AM/PM...
- Page 52 Warranty FHP Manufacturing warrants this equipment to be free from defects in material and workmanship for a period of one year from the shipment date. The energy recovery wheel is warranted to be free from defects in material and workmanship for a period of five years from the shipment date. Any units or parts which prove defective during the warranty period will be replaced at our option when returned to our factory, transportation prepaid.