User's Manual
Table Of Contents
- Table of Contents
- General Aspects
- About This Manual
- Features of Fluke 434-II/435-II/437-II
- Basic Operations and Menu Navigation
- Display Information
- Input Connections
- Scope Waveform and Phasor
- Volts/Amps/Hertz
- Dips & Swells
- Harmonics
- Power & Energy
- Energy Loss Calculator
- Power Inverter Efficiency
- Unbalance
- Inrush
- Monitor - Power Quality Monitoring
- Flicker
- Transients
- Power Wave
- Mains Signaling
- Logger
- Shipboard V/A/Hz
- Cursor and Zoom
- Setting up the Analyzer
- Using Memory and PC
- Tips and Maintenance
- Specifications
- Appendices
- Index
Fluke 434-II/435-II/437-II
Users Manual
14-4
Tips and Hints
The voltages and currents in the Meter screen can e.g. be used to check if power applied
to a 3-phase induction motor is in balance. Voltage unbalance causes high unbalanced
currents in stator windings resulting in overheating and reduced motor life. The Negative
Voltage component Vneg. should not exceed 2 %. Current unbalance should not exceed
10 %. In case of too high unbalance, use other measuring modes to further analyze the
power system.
Each three phase voltage or current can be split-up into three components: positive
sequence, negative sequence, and zero sequence.
The positive sequence component is the normal component such as present in balanced
3-phase systems. The negative sequence component results from unbalanced phase-to-
phase currents and voltages. This component for instance causes a ‘braking’ effect in
3-phase motors: this will result in overheating and life reduction.
Zero sequence components may appear in an unbalanced load in 4 wire power systems
and represent the current in the N (Neutral) wire. Unbalance exceeding 2 % is considered
as too high.