GE Multilin
Sub Meters
39
5.4.2.1.
CT Connection Reversal
To check the polarity of the CT after the monitor has been installed, simply look at the phase-
wise W (Watt) readings to see that each of the readings are positive (assuming you are
consuming power). If one of the W readings is negative, that particular phase CT is reversed
and must be corrected. On the other hand if you’re Exporting power, all three phase-wise W
readings must be negative.
5.5. Setup – System Type
The EPM 2000 needs to know what type of 3-phase system it is connected to. This is
programmed in the
Setup procedure
, before using the meter. The meter does allow you to
change this setting while it is running; however, this capability is meant for correcting a gross
error, or for training or educational purposes, not to be changed regularly. The options are:
•
Star (Wye). For Three Phase Four Wire, “Three Watt-meter” or “Three Element” circuits.
Here, all three voltage Phase signals, the Neutral voltage connection and all three current
input signals need to be wired in. Which means that all the 4 voltage terminals and 6
current terminals described in the following section, need to be wired.
This setting is also used for Single Phase Circuits. Here, the V1 and VN terminals as well
as the A11 and A12 terminals will be used to sense a single voltage and a single current.
•
Delta. For Three Phase, Three Wire, “Two Watt-meter” or “Two Element” circuits.
5.6. Phase Labels
The Phase Labels shown on the display are programmable via the EPM 2000 Front Panel Set
up menu. The choices available are: 123 (factory set), ryb, rst, Pqr, Abc
5.7. Connection Diagrams
Choose the diagram below that best describes your application. You must ensure that the CT
phase and corresponding PT phase are identical and that the CT polarity is correct as
explained in “
CT Polarity
” above. Follow the outlined procedure to verify correct connection.