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Heat Recovery Wheel Control Systems
You can control HRW systems with individual DDC units or by building
control systems.
Wheel Control (Speed Control Signal by Others)
On/Off Control
Rotor will receive power and will operate when the main disconnect
is turned on. A modulating signal is required to control the Rotor
speed. The controller can be set up for the following input signals:
(0-5V, 0-10V, 1-5V, 2-10V, 5-10V, 10-0V, 10-2V, 10-5V, 0-20V Phase
cut, 0-20mA, and 4-20mA). The Rotor can be turned on and off remotely
by removing white jumper from terminals #5 and #6 in wheel speed
control panel and connecting remote switch as indicated.
Rotation Detection and Alarm
A magnet fitted to the periphery of the rotor actuates a pulse
sensor once every revolution. Under normal operation the internal
contacts are in the energized position (contact closed between
#15 and #13). If the drive belt should fail or if the drive stops,
after 20 minutes the internal contacts shall close between #15
common and #14 NC), sending a signal to a remote alarm furnished
by others.
Automatic Purge
When wheel is at minimum signal or zero recovery, the wheel will
automatically run at minimum speed for 10 seconds every 30 minutes
to ensure that the rotor surface is kept clean.
Gentle Starting
The control unit soft-starts the wheel, taking approximately 30
seconds to ramp up the wheel to maximum speed. This extends the
life of the drive and belt.
RECOMMENDED TEMPERATURE CONTROLS (Control Signal by Others)
Maximum Discharge Temperature Speed Control
The remote modulating signal shall modulate the speed of the rotor
to maintain a maximum Supply Air discharge temperature leaving
the Rotor (T-SA). As T-SA rises above the recommended setpoint
of 58 F, rotor speed is reduced to decrease rotor effectiveness.
If T-SA is below setpoint, the rotor runs at maximum speed with
maximum recovery.
Summer Mode Control
When the Outside Air temperature (T-OA) rises above the return
air temperature (T-RA), the rotor should be run at maximum speed
for maximum recovery.
Frost Control
When the exhaust temperature (T-EA) leaving the AIRotor falls
below the recommended setpoint of 15oF, the rotor speed is reduced
to reduce heat recovery and maintain a minimum exhaust temperature
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