Woodward MFR500-6M/WK0400 + DPC USB 8444-1070

Undervoltage (Level 1 & 2) ANSI# 27

Voltage is monitored according to how the parameter “Voltage

measuring” (parameter 1851 Ä p. 41) is configured. This controller

provides the user with two alarm levels for undervoltage. Both

alarms are definite time alarms.

Monitoring for undervoltage faults is performed in two steps.

The diagram listed below shows a frequency trend and the associ

ated pickup times and length of the alarms.

4.4.3 Overfrequency (Level 1 & 2) ANSI# 81O

This controller provides the user with two alarm levels for overfre

quency. Both alarms are definite time alarms.

Monitoring for overfrequency faults is performed in two steps.

The diagram listed below shows a frequency trend and the associ

ated pickup times and length of the alarms.

Underfrequency (Level 1 & 2) ANSI# 81U

This controller provides the user with two alarm levels for underfre

quency. Both alarms are definite time alarms.

Monitoring for underfrequency faults is performed in two steps.

The diagram listed below shows a frequency trend and the associ

ated pickup times and length of the alarms.

4.4.5 Positive Load (Level 1 & 2) ANSI# 32

The power is monitored depending on parameter “Voltage meas

uring” (parameter 1851 Ä p. 41) and parameter “Current meas

uring” (parameter 1850 Ä p. 40).

If the single- or three-phase measured real power exceeds the

configured limit, the alarm will be issued.

Both alarm limits may either be positive or negative.

Description

If the monitored load exceeds the threshold value for the delay time config

ured here, an alarm will be issued.

Notes

If the monitored load falls below the threshold (minus the hysteresis) before

the delay expires the time will be reset.

The relay configured here is activated if the respective monitoring functions

triggers. If “None” is configured here, no relay is activated in this case.

Notes

Whether the relay is energized or de-energized depends on the configuration

of the relay function (parameter 6920 Ä p. 43 , 6921 Ä p. 43. 6922 Ä p. 43

and 6923 Ä p. 43).

Negative Load (Level 1 & 2) ANSI# 32R/F

General notes

The power is monitored depending on parameter “Voltage meas

uring” (parameter 1851 Ä p. 41) and parameter “Current meas

uring” (parameter 1850 Ä p. 40).

If the single- or three-phase measured real power is below the con

figured limit, the alarm will be issued.

Both alarm limits may either be positive or negative.

The negative load monitoring follows the same principle as the

positive load monitoring, but triggers when the value falls below the

threshold.

Unbalanced Load (Level 1 & 2) ANSI# 46

Unbalanced load is monitored according to how the parameters

“Voltage measuring” (parameter 1851 Ä p. 41), “Current meas

uring” (parameter 1850 Ä p. 40) and “Phase rotation” (parameter

3954 Ä p. 41) are configured.

The unbalanced load alarm is a phase imbalance alarm. Unbal

anced load is determined by calculating the negative sequence

component of a three phase system. This value is derived from the

three current components and the angle between them. Unbal

anced load monitoring is only active if “Current measuring” (param

eter 1850 Ä p. 40) is configured to “L1 L2 L3” and “Voltage meas

uring” (parameter 1851 Ä p. 41) is either configured to “3Ph 4W”

or “3Ph 3W”. The threshold is defined as the percentage of that

value relative to the nominal current. The protective function is trig

gered if this percentage value is exceeded