LE6XRT ERV
RENEWAIRE.COM
INSTALLATION, OPERATION AND MAINTENANCE MANUAL
1.800.627.4499
28
ELECTRICAL CONNECTIONS
Dampers
When one or both of the airstreams are factory-provided with Dampers, the control sequence for that
airstream’s blower is as follows:
• External control calls for operation and damper immediately starts to open.
• After about 30 seconds, damper is open fully and the damper actuator end switch closes.
• The damper actuator end switch completes a low-voltage circuit that turns on the appropriate
blower, either through the blower’s motor starter, or through the blower’s VFD.
• If that blower is controlled by a motor starter, it starts immediately
Variable Frequency Drives (VFDs)
When one or both of the blowers are factory-provided with VFDs, the response of the Blower Motor
depends on the VFD’s settings and connected control signal.
Typically, the VFD will be connected to a control device which provides a variable analog signal
(0-10VDC or 4-20mA) as an input to the VFD. The VFD must be set to respond to this input with
appropriate motor operating speeds.
Alternately, the VFD might be controlled by a Time Clock, which defines different operating periods
(e.g. “occupied” and “unoccupied”). Each period calls on one of up to three different VFD Presets to
provide different motor speeds in different operating periods.
