Motor monitoring relays

The PMDsigma electronic monitoring relays monitor values such as voltage, current, temperature or phase sequence. The first unit in the range monitors true power. This provides an early warning system for hazardous plant conditions, with no requirement for additional sensors.

The compact unit PMD s10 provides an indication of the motor load through the true power. It monitors the thresholds, while at the same time providing an analog voltage or current value which is proportional to the true power. This means that both the overload and underload thresholds can be monitored via an analog signal (PLC) or via the integrated relay.

Motors with a rating of up to 11 kW can be monitored directly; larger motors can be monitored via current transformers. Motor voltages of up to 550 are possible. The PMD s10 can process frequencies from 0 up to 1000 Hz. It is therefore very flexible and is suitable for both DC and AC motors as well as frequency-controlled drives. Motor start-up and transient power fluctuations can be suppressed, so that high inrush currents do not affect the unit.

Peak values during operation can be stored and called up via the display. While the operation is running the unit can display up-to-date values such as current power consumption. An integrated operating hours and cycle counter enables preventive maintenance, which reduces repair and downtimes.

With the PMD s10, users can implement an early warning system for hazardous plant conditions, without the need for additional sensors. Filter plugging or wear-and-tear on mechanical components such as bearings can be identified before they lead to failure.