Woodward MFR300 75M/SU03, Transducer 8444-1093 8444-1094 8444-1095

Woodward  MFR300 75M/SU03, Transducer  8444-1093  8444-1094 8444-1095

Product number: 8444-1093

Manufacturer product number: 8444-1093

Description: woodward: MFR300 75M/SU03. Transducer

Unbalanced Load (Level 1 & 2) ANSI# 46

General notes

Unbalanced load is monitored according to how the parameters “Voltage measuring”

(parameter ╚═▷ 1851), “Current measuring” (parameter ╚═▷ 1850) and “Phase rotation”

(parameter ╚═▷ 3954) are configured

A vector/phase shift is defined as the sudden variation of the

voltage curve which may be caused by a major source load

change.

8444-1093

The unit measures the duration of a cycle, where a new measure

ment is started with each voltage passing through zero. The meas

ured cycle duration will be compared with an internal quartz-cali

brated reference time to determine the cycle duration difference of

the voltage signal.

A vector/phase shift as shown in Fig. 37 causes a premature or

delayed zero passage. The determined cycle duration difference

corresponds with the occurring phase shift angle.

The monitoring may be carried out three-phase or one/three

phase. The monitoring can be configured in different ways. The

vector/phase shift monitor can also be used as an additional

method to decouple from the grid. Vector/phase shift monitoring is

only enabled after the monitored voltage exceeds 50% of the PT

secondary rated voltage

The unbalanced load alarm is a phase imbalance alarm. Unbalanced load is determined

by calculating the negative sequence component of a three phase system: The three

current components and the angle between them. Parameter “Monitoring Modes”

(parameter ╚═▷ 2414) defines how to calculate in detail accoring to typical standards.

Unbalanced load monitoring is only active if “Current measuring” (parameter ╚═▷ 1850) is

configured to “L1 L2 L3” and “Voltage measuring” (parameter ╚═▷ 1851) 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 triggered if this

percentage value is exceeded.

Voltage Asymmetry (Level 1 & 2)

General notes

Voltage asymmetry is determined by calculating the negative sequence component of a

three-phase system. This value is derived from the three delta voltages (phase-phase).

Voltage asymmetry monitoring is only active if “Voltage measuring” (parameter ╚═▷

1851) is configured to “3Ph 4W” or “3Ph 3W”. The threshold is defined as the percentage

of that value relative to the nominal delta voltage. The protective function is triggered if

this percentage value is exceeded.