Uses of the PT/CT ratio on E5600



Goals and Symptoms

This article explains the importance of PT/CT ratio on E5600 meter.

Causes and Fixes

On the E5600 the PT/CT ratios do not have any effect on the rate of pulses. The PT/CT ratios only affect values shown on the meter display and through MODBUS. By default the PT/CT ratios are set to 1, use this ratio to see what the meter is measuring on its blades or secondary side.
When the voltage and current that the meter is monitoring at the secondary side of the PT/CTs is low it will take time before the KWh, kVARh, kVAh etc., in the real time screen, will show some values. In the example in Figure 1 and 2 there are no values for KWh, KVARh and kVAh even after five minutes. Same is true for the values displayed on the screen. Only integer values are displayed in the real time module and the meter display. In order to see the values that are less than 1 KWh/KVARh/ kVAh increases the PT/CT ratios and keep in mind that the new energy values have scaling.

Figure 1

Figure 2

Figures 3&4 below show the voltage and current applied to the 16S E5600 meter in the above example.

Figure 3

Figure 4


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Date Created: October 5, 2009
Last Revised: October 20, 2009
Original Author: SN
All content © 1992-2009 Schneider Electric

Legacy KB System (APS) Data: RESL200294 V1.0, Originally authored by MiNe on 10/21/2009, Last Edited by MiNe on 10/21/2009
Related ranges: E5600