Basic Documentation

Page 4 of 9 Siemens Building Technologies, Inc.
Document No. A6V10431169
MWh meter Digital input status
Digital output status
11. The VFD’s shall include a Quick Start-up wizard that leads the user through the 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 point sources, a sleep mode function, PID set point boost and a
feed forward function to improve process response.
18. Run permissive circuit shall be included for damper or valve control.
19. The customer terminal strip shall be isolated from the line and ground.
• duty current rating.
20. The overload rating of the drive shall be 110% of its normal duty current rating for 1 minute in every 10 minutes.
21. The VFD shall have integrated harmonic filters equivalent to 5% impedance line reactors. .
22. The VFD shall incorporate a Multi-Pump Controller Wizard capable of controlling up to five motors. The VFD is
connected to one motor which is the "regulating" motor connecting and disconnecting the other motors to/from
the mains, by means of contactors controlled with relays to maintain a given set point. This function shall have an
auto-change function for changing starting order of pumps which allows for equal wear on all pumps.
23. The VFD shall be capable of sensing a loss of load (broken belt / no water in pump) or high current mechanical
sensing failure, and signal the loss of load condition. The drive shall be programmable to signal this condition via a
keypad warning, relay output and/or over the serial communications bus.
24. The VFD shall include a motor switch ride through and is enabled or disabled through the keypad. This feature
allows the motor maintenance switch to be opened and closed without stopping or tripping the drive.
All VFDs to have the following adjustments:
1. Three (3) programmable critical frequency lockout ranges to prevent the VFD from operating the load continuously
at an unstable speed.