Operating Instructions

SED2 VFD Operation & Maintenance Manual
60 Siemens Building Technologies, Inc.
P2181, Belt failure detection mode
Set the desired reaction of drive belt failure detection via parameter P2181. Possible settings:
0 Belt failure detection disabled (factory setting).
1 Warn low torque/speed.
2 Warn high torque/speed.
3 Warn high/low torque/speed.
4 Trip low torque/speed.
5 Trip high torque/speed.
6 Trip high/low torque/speed.
Suggested setting: 1 Warn low torque/speed.
P2191, Belt failure speed tolerance
Use parameter P2191 to set the maximum permissible deviation of the pulse train frequency
(actual value) generated by the sensor from the SED2 output frequency (setpoint). If the
tolerance band for frequency is exceeded, a warning or trip occurs.
Setting range: 0 to 20 Hz.
Factory setting: 3 Hz.
In manual mode, vary the torque frequency in the selected range to check the function. Then
change over to automatic control.
Staging Pumps or Fans
Motor staging controls up to two additional pumps or fans based on the integrated PID
control system. The complete system comprises a pump (fan) controlled by the SED2, and
up to two additional pumps (fans) switched by contactors or motor starters.
NOTES:
1. Contact speed pumps must be protected per NEC or UL.
2. Contactors or starters are not supplied with the drive.
Relay switching contacts integrated in the SED2 control the contactors or motor starters.
Figure 35 shows a typical pump system. A similar system comprised of fans could be used
for ventilating systems.