For Vektor Fans without a Weatherhood

A guard / cover is located on the side of the plenum section. Removal of the guard / cover gains access to the damper linkages, actuator (optional from factory) and transformer (optional from factor). The entire bypass damper assembly can be removed through this opening. The isolation damper assembly can be removed from its location by unbolting the frame from the plenum and removing the flex connector.

If the Vektor units were not supplied with optional actuators, the dampers have an extended jackshaft for field mounting a customer supplied actuator.

Motor Disconnect Wiring & Isolation Damper Wiring Diagram

LINE IN

208/230/460/575 V

3 PHASE

DISCONNECT

208/230/460/575 V

3 PHASE

MOTOR 208/230/460/575/60/3

Disconnect is mounted to fan housing. Transformer is mounted to bypass air plenum near isolation damper actuator motor. For systems that ship un-assembled because of physical size, this connection at disconnect from transformer must be ﬁeld installed. Wires with conduit and ﬁtting are provided pre-connected to transformer.

OPTIONAL ISOLATION

DAMPER CONTROL

TRANSFORMER

208/230/460/575 V 1 PHASE

24/115 V 1 PHASE

ISOLATION DAMPER

ACTUATOR MOTOR

POWER OPEN/SPRING CLOSE

	NOTE: If a Variable Frequency Drive is used to control fan speed,
FIELD WIRING	transformer and actuator will not function properly when wired as
FACTORY WIRING	shown. Transformers must be wired independently from VFD control.

Applications with Variable Frequency Drives (VFD)

For Vektor systems with single-point, three-phase wiring per blower, the isolation damper actuator will be powered via a step-down transformer, which is wired to the fan disconnect, as shown in the diagram above.

If fan flow (motor speed) is to be controlled using a VFD, the reduced voltage and frequency supplied to the fan will cause control problems with the isolation damper actuator.

When a Vektor control sequence requires the use of a VFD, it is suggested that the control contractor supply the isolation damper actuator voltage — independent of the power supplied to the Vektor fan motor.

Isolation Damper Control

Isolation dampers on de-energized fans are to be closed to maintain system negative pressure and prevent reverse “free-wheeling” of de-energized blower(s). Isolation dampers shall be opened immediately upon fan energizing.

Greenheck Fan 47555 specifications For Vektor Fans without a Weatherhood, Isolation Damper Control

Models: 47555