Basic Documentation

Disclaimer: These are sample drawings and sequences. Designers are responsible for
finalizing the content for their particular projects.
monitored and view via the keypad. All parameters viewed from the list below
shall be capable of being displayed at all times. The display shall be in complete
English words (alpha-numeric codes are not acceptable).
a. Output Frequency Motor Speed (RPM, %, or Eng units)
b. Motor Current Calculated Motor Torque
c. Calculated Motor Power (kW) DC Bus Voltage
d. Output Voltage Heatsink Temperature (deg F)
e. Analog Input Values Analog Output Value
f. Keypad Reference Values Elapsed Time Meter (resettable)
g. KWh meter (resettable) MWh meter
h. Digital input status Digital output status
11. The VFD’s shall include a Quick Start-up wizard that leads the user through the
most typical HVAC required parameters.
12. The VFD shall have the ability to automatically restart after an overcurrent,
overvoltage, undervoltage, or loss of input signal protective trip. The number of
restart attempts, trial time, and time between reset attempts shall be
programmable.
13. The VFD shall be capable of starting into a rotating load (forward or reverse) and
accelerate or decelerate to setpoint without safety tripping or component damage
(flying start).
14. The VFD shall also be capable of DC injection braking that can be employed to
stop a free wheeling motor prior to starting to avoid overvoltage nuisance
tripping.
15. The VFD shall have the ability to be programmed to automatically extend the
ramp-down time as required to keep the drive from tripping on over-voltage
caused by regeneration of power by the load
16. If the input reference (0/4-20mA or 0/2-10V) is lost, the VFD shall give the user
the option of either (1) stopping and displaying a fault, (2) running at a
programmable preset speed, (3) hold the VFD speed based on the last good
reference received, or (4) cause a warning to be issued, as selected by the user.
The drive shall be programmable to signal this condition via a keypad warning,
relay output and/or over the serial communication bus.
17. The VFD shall include two-zone PID controllers that allow the drive to maintain
PID control from two separate feedback signals. VFD shall include two PID set