READ AND SAVE THESE INSTRUCTIONS PART #459657 ENERGY RECOVERY UNIT with HEATING ® Models: ERH-20, 45, 55, & 90 INSTALLATION, OPERATION AND MAINTENANCE MANUAL **WARNING** DISCONNECT AND SECURE TO THE "OFF" POSITION ALL ELECTRICAL POWER TO THE UNITS PRIOR TO INSPECTION OR SERVICING. FAILURE TO COMPLY WITH THIS SAFETY PRECAUTION COULD RESULT IN SERIOUS INJURY OR DEATH. Energy Recovery Wheel **IMPORTANT** ALL FACTORY PROVIDED LIFTING LUGS MUST BE USED WHEN LIFTING THE UNITS.
TABLE OF CONTENTS Storage . . . . . . . . . . . . . . . . . . . . . . . . . . 2 General . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Basic Operation . . . . . . . . . . . . . . . . . . . 3 Installation . . . . . . . . . . . . . . . . . . . . . . . 3 Lifting . . . . . . . . . . . . . . . . . . . . . . . . . .3 Recommended Roof Openings . . . . . . .3 Unit Weights . . . . . . . . . . . . . . . . . . . . .3 Roof Curb Mounting . . . . . . . . . . . . . . .4 Duct Work Connections . . . . . . . . . . . .
BASIC OPERATION The ERH brings in fresh, outdoor air and removes stale, exhaust air. Prior to discharging the exhaust air, the energy recovery wheel transfers energy from the exhaust air to the outdoor air at an efficiency of 70-80%. Simply put, this unit preconditions the outdoor air to save money on heating and cooling costs. This particular unit also has a heater option available after the recovery wheel to further increase the fresh air temperature if desired.
ROOF CURB MOUNTING 1. Factory Supplied Roof Curbs Roof curbs are Model GKD, which are shipped in a knockdown kit and require field assembly (by others). Assembly instructions are included with the curb. 2. Cut Roof Opening and Locate Curb Layout the unit roof opening such that the supply discharge & exhaust inlet of the unit will line up with the corresponding ductwork (refer to Recommended Roof Openings on page 3). Be sure to allow for the recommended service clearances.
INSTALLATION (continued) WEATHERHOODS Supply weatherhood will be factory mounted. The exhaust weatherhood is shipped separately as a kit with its own instructions. EXHAUST DAMPERS Backdraft dampers for exhaust discharge are mounted in the unit. Motorized dampers are shipped loose (inside ERH) and must be field installed. ELECTRICAL CONNECTIONS The electrical supply must be compatible with that shown on the nameplate: voltage, phase, and amperage capacity.
SERVICE CLEARANCES / ACCESS PANEL LOCATIONS for Model ERH ERH-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.
WATER COIL LOCATION AND CONNECTION A hot water coil can be factory installed in the coil section of the ERH. The coil section is downstream of the energy wheel on the supply air side of the unit. Coil connections are external to the unit as shown below. Coil connections not external have been ordered from the factory with internal or exhaust air stream connections.
ELECTRIC HEATER APPLICATION/OPERATION Factory installed electric heaters can be provided for preheat and/or post-heat (see FIGURE 11). An electric preheater warms the outdoor air prior to the energy recovery wheel to prevent frosting on the wheel. An electric post-heater warms the air leaving the energy recovery wheel to a user specified discharge temperature. Electric heaters are available in 208, 230, or 460 Vac (refer to heater nameplate for voltage).
FROST CONTROL APPLICATION/OPERATION When outdoor air temperatures are extremely cold, moisture condensation and frosting on the energy recovery wheel is possible. Frost control is an optional feature that will prevent wheel frosting.
ECONOMIZER APPLICATION/OPERATION The energy recovery wheel may be de-energized for the purpose of providing economizer (free cooling) operation. This can be achieved with a signal from a Temperature or Enthalpy sensor mounted in the supply air inlet compartment (see FIGURE 13). This Primary sensor will de-energize the energy wheel when the outdoor air temperature (factory default is 65°F) or enthalpy (factory default is the ‘D’ setting) is below the field adjustable set point.
START UP CHECKS **WARNING** DO NOT OPERATE ENERGY RECOVERY VENTILATOR WITHOUT THE FILTERS AND BIRDSCREENS INSTALLED. THEY PREVENT THE ENTRY OF FOREIGN OBJECTS SUCH AS LEAVES, BIRDS, ETC. DO NOT REMOVE ACCESS PANELS OR OTHER UNIT COMPONENTS WHILE STANDING ON A LADDER OR OTHER UNSTEADY BASE. ACCESS PANELS AND UNIT COMPONENTS ARE HEAVY AND SERIOUS INJURY MAY OCCUR.
Check pulleys and belts for proper alignment to avoid unnecessary belt wear, noise, vibration and power loss. Motor and drive shafts must be parallel and pulleys in line (see FIGURE 16). FAN RPM The adjustable motor pulley is preset at the factory to the customer specified RPM. Fan speed can be increased or decreased by adjusting the pitch diameter of the motor pulley. Multi-groove variable pitch pulleys must be adjusted an equal number of turns open or closed.
ROUTINE MAINTENANCE CAUTION: See **WARNING** on Page 1 and 11 Once the unit has been put into operation, a periodic maintenance program should be set up to preserve the reliability and performance. Items to be included in this program are: • • • • • • • BELTS MOTORS WHEEL AND FASTENERS VIBRATION FILTER MAINTENANCE COIL MAINTENANCE ENERGY WHEEL CASSETTE FAN BELTS Belts tend to stretch after a period of time. They should be periodically checked for tension and wear.
VIBRATION Excessive vibration maybe experienced during initial start-up. Left unchecked, excessive vibration can cause a multitude of problems, including structural and/or component failure. The most common sources of vibration are listed below. Many of these conditions can be discovered by careful observation. Refer to the troubleshooting section of this manual for corrective actions.
WATER COIL MAINTENANCE CAUTION: See **WARNING** on Page 1 and 11 FILTERS Filters upstream of the coil should be checked regularly. If the filters are dirty, they should be cleaned or replaced. It is important that the coils stay clean to maintain desired airflow. See page 14 for more information on filter maintenance. COIL MAINTENANCE 1. Coils must be clean to obtain maximum performance. Check once a year under normal operating conditions and, if dirty, brush or vacuum clean.
ROUTINE ENERGY RECOVERY WHEEL MAINTENANCE CAUTION: See **WARNING** on Page 1 and 11 MAINTENANCE OF THE ENERGY RECOVERY WHEEL Annual inspection of the energy recovery wheel is recommended. Units ventilating smoking lounges and other non-clean air spaces should have energy recovery wheel inspections more often based upon need. Inspections for smoke ventilation applications are recommended bimonthly to quarterly until a regular schedule can be established.
REMOVING THE ENERGY RECOVERY WHEEL SEGMENTS Model ERH-20, 45, 55, & 90 Steel retainers are located on the inside of the wheel rim (FIGURE 22). Push the retainer toward center of wheel, then lift up and away to release segments (FIGURE 23). Bracket Segment Retainer Lift Away From Segment CatchSegment Retainer Inside of Wheel Rim Spoke Push Toward Center Cen ter of W hee l FIGURE 22 IMPORTANT! PLACE RETAINERS BACK IN THE ORIGINAL POSITION BEFORE ROTATING THE ENERGY RECOVERY WHEEL.
PARTS LIST 7 3 6 8 1 5 2 9 10 7 4 Model ERH (shown with indirect gas heater) 1. Supply blower - Forward curved fan - Adjustable motor mount for belt tensioning - Adjustable sheaves for speed control 2. Vibrations isolators (quantity 4 per blower) - Neoprene 3. Energy recovery wheel cassette 4. Removable energy recovery wheel segments 5. Optional supply weatherhood with 2 in. aluminum mesh filter 6. Optional exhaust weatherhood with birdscreen 7.
Trouble Shooting Symptom Blower Fails to Operate Motor Starters “Chatter” or Do Not Pull In Motor Over Amps Low Airflow (cfm) Possible Cause Corrective Action Blown fuse or open circuit breaker. Replace fuse or reset circuit breaker and check amps. Defective motor or capacitor. Replace Motor starter overloaded. Reset starter and check amps. Electrical. Check for On/Off switches. Check for correct supply voltage. Drive. Check for broken or loose belts. Tighten loose pulleys.
Trouble Shooting Symptom Possible Cause Corrective Action One or Both Blowers Turn Off Intermittently and Back on After About 2 Minutes Blower fan motor overloads are tripping and auto-resetting. Decrease fan speed. Exhaust Only frost control sensors are tripping. Adjust frost temperature sensor set point as needed. Air seals are too tight. See Energy Recovery Wheel on page 12 “Economizer” sensors are operating. Adjust temperature or enthalpy set points as needed. No power to wheel motor.