Selecting a Motor
IMPORTANT:
Do not exceed the VFD66 control’s
maximum output ampere rating. Exceeding the
control’s maximum output ampere rating can cause
the VFD66 control to shut down on an overload fault.
The VFD66 control allows the motor to develop torque
that varies with the current. The motor provides
maximum torque at its maximum current draw. Use
these guidelines to select the proper motor for use with
the VFD66 control.
!
CAUTION: Risk of Property Damage.
Use only three phase motors approved by the
manufacturer for speed control applications with the
VFD66 Control. Failure to use a three phase motor
may damage the motor and other property.
Required Motor Specifications
Motors used with the VFD66 Series Controls must:
have variable torque operation
be UL Recognized and CSA Certified, or equivalent
be AC induction 3-phase motors
be rated for 208/230 VAC, 60 Hz (230 VAC, 50 Hz) or
460 VAC, 60 Hz (400 VAC, 50 Hz)
have ball bearings
have an Inverter Rating (400/460 VAC motors)
have Insulation Class F or better
On 400/460 VAC models, the motor insulation system
must be deemed suitable by the motor manufacturer
for use on PWM (Pulse Width Modulated) IGBT
(Insulated Gate Bipolar Transistor) variable frequency
drives. These are also referred to as inverter-rated
motors.
The VFD66 controls are suitable
for use with
thermally protected motors or the like
intended by
their manufacturer for fan speed modulating
applications.
Multiple Motors
A VFD66 control can control multiple motors; however,
the sum of the Full Load Amperes (FLA) ratings for the
motors must not exceed the maximum output
amperage rating of the VFD66 control, including any
de-rating due to altitude and/or temperature.
Ordering Information
To select the proper model of the VFD66 control for a
specific application:
1. Locate the nameplate (dataplate) on the motors
intended for use with the VFD66 control.
400/460 VAC motors for use with the
VFD66 controls must be inverter-rated motors.
See
Selecting a Motor
for further information.
2. Identify the FLA ratings of each motor to be
controlled by the VFD66 control. If more than one
motor will be controlled, add the ratings of all the
motors to determine the total FLA.
3. Adjust the VFD66 control’s current rating for
temperature and altitude. See
De-Rating the
VFD66 Control for High Temperatures and High
Altitudes
.
4. Compare the sum of the amperage draw of the
motors to the adjusted current rating of the VFD66
control. If the current required is between two
VFD66 control models, select the model with the
higher amperage rating.
5. Configure the product number of the desired
VFD66 control by adding the appropriate 3-letter
suffix to VFD66. See for product number
configuration. See Table 15 for standard models.
See Table 13 for input devices and other
accessories.
For example, a
VFD66BAA
would be a
VFD66
control
rated at 1.8 amperes, 460 VAC at 60 Hz (
B
),
NEMA 1 enclosure (
A
), Dual analog input signal (
A
).
Contact Johnson Controls/PENN application
engineering at 1-800-275-5676 for more information.
14
VFD66 Series Condenser Fan Speed Controls Product/Technical Bulletin