Accurate measurement capabilities for VSDs

This article describes an instrument which is particularly well suited for use during installation and service of variable-speed motor drives, showing the required readings and providing automatic triggering even on complex modulated drive output signals. The instrument makes analysing V/Hz ratio easier than ever and makes it possible to analyse the behaviour of the system and find possible causes for unstable motor behaviour in the Variable Speed Drive (VSD) configuration.


Take note

  • Modern VSDs have provided many benefits to users.
  • The V/Hz ratio is an important parameter of a VSD and requires that output voltage and frequency are measured simultaneously.
  • Measurement devices that are configured specifically to troubleshoot VSDs are available.


Published as:

Checking voltage frequency ratios on VSDs

By W Thompson, Fluke

Electricity+Control, July 2011 (pgs 20 – 21)