GE Multilin 515 Instruction Manual

GE
Grid Solutions
515
Blocking and Test System
Instruction Manual
GE Publication Number: 1601-0024-A7
Copyright © 2020 GE Multilin
Introduction
The GE Multilin 515 Blocking and Test Module has the following features:
• 14 Pole switchbank
• CT inputs short when current switches are opened
• Current injection for each phase
• Ground terminal
Description
The 515 Blocking and Test Module provides an effective means of trip blocking, relay isolation and testing of GE Multilin relays. By opening the
switches and inserting test plugs, phase and residual currents from the primary CTs can be monitored. Currents can be injected into the relay from
a secondary injection test set during commissioning.
Prior to testing, the trip and auxiliary circuits must first be opened to prevent nuisance tripping; CTs can then be shorted. Conversely, when the test
is complete and the relay put back into operation, the CT switches should be closed first to ensure normal operation of the relay, prior to closing
the trip and auxiliary circuits.
Installation
Shorting switches are provided for connection of 3 phase CTs (current transformers) and a separate core balance ground fault CT or 3 phase CTs
connected for residual ground fault sensing.
When each CT switch is opened, the CT is shorted. It is essential that the CT is connected to the shorted side of the switch as shown in the following
figure, otherwise dangerously high voltages would be present from the open circuited CTs.
When the switches are open, test plugs can be inserted to either inject signals into the relay wired to the switches or monitor signals such as CT
current from the switchgear.
Figure 1: Typical wiring for connecting a 515 to a protective relay
The 515 Blocking and Test Module consists of a metal chassis attached to the 515 test switches that slides into the panel. A single cutout in the panel, as per
the dimensions shown in Figure 3, is required to mount the 515 test switches.
515 Blocking and Test System – Instruction Manual
• Ability to visually isolate (open) trip relay output circuits
• Cover provided
• Suitable for utility and industrial use
• 515 test plugs available
Figure 2: Typical Wiring for Zero-Sequence Ground Fault
1