CHAPTER 3: INSTALLATION
WIRING
MULTILIN DGPR – INSTRUCTION MANUAL
15
Difference between CT connections of DGP and DGPR
Although the DGPR is a retrofit solution for the DGP and the attempt was made to maintain
as much similarity as possible, there are some differences. Figure 13 shows the difference
in the CT connections.
Figure 13: Typical CT connections
DGPR and DGP use residual connections. DGP uses a hard-wire approach to sum all of the
current in INS or INR, while the 51N element in the DGPR is connected in the common
neutral connection of the current transformer, which is the most common connection
arrangement. On four-wire circuits, the fourth current transformer is connected in the
neutral circuit, shown with a dotted line in the Figure 14.
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