YOKOGAWA WT5000 Features Guide

6-2
IM WT5000-01EN
Efficiency Equation (Efficiency)
You can create an efficiency equation by combining measurement function symbols. This instrument can
determine the energy conversion efficiency of the device using the numeric values of the measurement
functions.
η1 to η4
You can create four efficiency equations (η1 to η4), using the following measurement functions as operands.
• The active powers of each element (P1 to P7)
• The active powers of the Σ functions (PΣA to PΣC)
• The motor output (Pm1 to Pm4, on models with the motor evaluation 1 or 2 option)
• Udef1, Udef2
Udef1, Udef2
To add active powers and motor output and use them in η1 to η4, use Udef1 and Udef2. You can add up to four
operands consisting of the measurement functions listed above.
Equation Examples
• Efficiency of a Single-Phase, Two-Wire Input/Single-Phase, Two-Wire Output Device
Input: Power of element 1 (P1)
Output: Power of element 2 (P2)
Efficiency equation: P2/P1 × 100 (%)
Converter
(inverter, etc.)
Input power: P1
Output power: P2
• Efficiency of a Single-Phase, Two-Wire Input/Three-Phase, Three-Wire Output Device
Input: Power of element 1 (P1)
Output: Σ power of elements 2 and 3 (PΣA)
Efficiency equation: PΣA/P1 × 100 (%)
• Efficiency of a Three-Phase, Three-Wire Input/Three-Phase, Three-Wire Output Device
Input: Σ power of elements 1 and 2 (PΣA)
Output: Σ power of elements 3 and 4 (PΣB)
Efficiency equation: PΣB/PΣA × 100 (%)
• Efficiency of Motor 1 with a Single-Phase, Two-Wire Input
Input: Power of element 1 (P1)
Output: Motor 1 output (Pm1)
Efficiency equation: Pm1/P1 × 100 (%)
• Efficiency of Motor 1 with a Three-Phase, Three-Wire Input
Input: Σ power of elements 1 and 2 (PΣA)
Output: Motor 1 output (Pm1)
Efficiency equation: Pm1/PΣA × 100 (%)
To correctly compute the efficiency, set the power coefficients of all elements so that all power units used in
the computation are the same. For example, the efficiency cannot be computed correctly if elements or wiring
units used in the computation have different power units, such as W (watt) and J (joule).
6 Computation and Output

YOKOGAWA WT5000 Specifications

General

Brand	YOKOGAWA
Model	WT5000
Category	Measuring Instruments
Language	English