Basic Documentation

Siemens Building Technologies, Inc. Page 5 of 9
Document No. A6V10431169
2. A custom PID preset for HVAC and fluid systems, allow a pressure or flow signal to be connected to the VFD, using
the microprocessor in the VFD for the closed loop control. A sleep mode shall be included in the PID functions.
This feature shall allow the motor to be stopped when at minimum speed for a user defined period, for additional
energy savings.
3. Two (2) programmable analog inputs shall accept a current or voltage.
4. Analog inputs shall include a filter to remove any oscillation in the input signal. The minimum and maximum values
(gain and offset) shall be adjustable within the range of 0 - 20 mA and 0 - 10 Volts. Additionally, the reference must
be able to be scaled so that maximum reference can represent a frequency less than 60 Hz, without lowering the
drive maximum frequency below 60 Hz. Process variables shall be capable of being inverted.
5. Six (6) programmable digital inputs for maximum flexibility in interfacing with external devices. These inputs can
also be used to activate the setpoints of individual control loops.
6. One (1) programmable analog output proportional to Frequency, Motor Speed, Output Voltage, Output Current,
Motor Torque, Motor Power (kW), DC Bus voltage, Active Reference, and other data.
7. Two (3) programmable digital relay outputs. The relays shall be rated for maximum switching current 8 amps at
250 Vac and 0.4A at 125 Vac. Outputs shall be full form C relay contacts; open collector outputs are not acceptable.
8. The VFD shall be capable of adding additional I/O as required for the system. The additional I/O shall mount in the
drive and not require bypass configuration. Additional I/O include
• Six (6) additional programmable digital inputs or outputs
• Five (5) digital inputs with a relay output
• 2 additional relay outputs with a thermostat
• One (1) each additional Analog Input and two (2) analog outputs
• Three (3) relay outputs
9. Fifteen (15) programmable preset speeds.
10. Two independently adjustable accel and decel ramps. These ramp times shall be adjustable from 1 to 3600
seconds.
11. The VFD shall be capable of catching a “spinning motor” as programmed by the user.
12. The VFD shall Ramp or Coast to a stop, as selected by the user.
13. The displayed operating information shall be user selectable and include up to nine parameters which can be
viewed and monitored at one time.
14. All applicable operating values shall be displayed in engineering (user) units.
15. The keypad shall include a backlit LCD display. The display shall be in complete words for programming and fault
diagnostics.
16. The keypad shall utilize wizards to help navigate your HVAC application. These wizards will walk you through the
steps required for PID set-up, Start-up and Multi-pump applications.
17. The VFD shall include a fireman’s override input.