Magic Aire HHA Series, Installation, Operation And Maintenance Manual

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035-000029-001 Page 20 HHA IOM 1.4 10/11/2021
NOTES:
1. This diagram represents the factory-installed electrical option with constant CFM control using the pres-
sure transducer mounted inside the unit. Control loop logic is contained in the VFD programming. VFD
keypad is mounted on outside of unit.
2. Typical wiring is shown. For exact wiring, refer to the wiring diagram provided with the unit.
3. Field wiring includes power wiring (upper left hand corner) and low voltage control wiring (terminal block
TB1).
4. Units ordered for 208V-240V voltage selection are factory wired for 240V. Field may rewire motor and
transformer primary tap for operation at 208V.
5. Selection of field provided and installed electrical components is the responsibility of the installer, in-
cluding branch circuit protection and wiring.
6. To start the fan, connect R and G to energize fan relay FR1. Fan speed is controlled by the VFD using
the pressure transducer signal to maintain a fixed airflow (constant pressure difference across the cali-
brated fan nozzle). See “VFD Parameter” section for airflow adjustment.
7. The control power (R and C at terminal block TB1) can be used to power a standard 24VAC thermo-
stat , DX relay and up to 2ea control valves.
INSTALLATION-ELECTRICAL (cont’d)
TYPICAL WIRING DIAGRAMS—
Control Option “D”, Constant CFM Control
208/230V—1
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