PM
-
3133i User
’s Manual v1.02
Last Revised: Apr. 2023 Page: 74
Copyright © ICP DAS Co., Ltd. All Rights Reserved.
E-mail: [email protected]
Q14. How to measure the Voltage large than 600V?
For service voltage above 600 Vac, voltage transformers (PTs) are used to step down the
voltage to a lower range that will work with a PM-3133i meter.
Selecting a Transformer:
Selecting the right voltage transformer is simple. Review the following
considerations to determine the best fit for your application.
Input Voltage:
Select a transformer that will operate on the supply voltage available at your facility
(Example: PRI. Voltage 720V; SEC. Voltage 120V). Check the connection diagram
(three-phase Y and delta; phase sequence) to ensure compatibility.
Adding potential transformers has the effect of reducing the measured line voltage by the PT
ratio (let's say 6:1 for this example). So a voltage of 720 Vac becomes 120 Vac. Since the
meter sees 120 Vac, many of the measurements it reports will be low by a factor of 6 unless
they are scaled up by 6.
Frequency:
If you are operating in the United States, you will most likely be operating on 60 Hz. However
should you need a 50 Hz rated transformer.
Accuracy: Transformer (PT) accuracy (Example: 1% or 3%) will influence the measurement.
Rated Output (VA): Example: 150 VA (50VA per phase).
