GE Industrial Solutions Neutral Rogowski Current Transformer User Manual
GE Energy
Neutral Assemblies
Manual
Neutral Rogowski Current Transformer (CT)
EntelliGuard R Circuit Breaker uses an air-core Rogowski Current sensor to measure
current level vs. an iron core style used in the legacy AK, AKR breakers.
imagination at work
Table of Contents
Related Publications ..................................................................................................................................................................2
Estimated Time to Complete Tasks ......................................................................................................................................... 2
General Description ...................................................................................................................................................................2
AKD-5—Neutral Disconnect Assembly (Breaker—N/A) ........................................................................................................ 2
AKD-5—Replace Iron Core Neutral CT with a Rogowski (Compartment) .........................................................................2
Neutral CT in Cable/Bus Compartment .......................................................................................................................................................... 3
AKD-5—Neutral Sensor Packaging ................................................................................................................................................................... 5
AKD-6/8—Neutral Rogowski Current Transformer (CT) .......................................................................................................6
Neutral Disconnect Assembly (AKD-6—Breaker Side) .............................................................................................................................. 6
Neutral Disconnect Assembly (Bus Compartment) ................................................................................................................................... 6
AKD-6/8—Rogowski Assembly Part Numbers ............................................................................................................................................. 7
AKD-6/8—Rogowski Assemblies ........................................................................................................................................................................ 7
Neutral CT assembly in Cable/Bus Compartment ..................................................................................................................................... 8
Wiring Diagram for the AK/AKR Retrofill ...............................................................................................................................9
Legacy Specifications ..............................................................................................................................................................10
Ordering Rogowski Replacements ........................................................................................................................................11
Notes ..........................................................................................................................................................................................12
Neutral Assemblies Manual
1
DEH-41531 02/12
Related Publications
Publication Publication Number
Brochure DEA-532
Snapshot DEE-543
Installation Manual AKD8 DEH-41549
Installation Manual AKD6 DEH-41548
Installation Manual AKD5 DEH-41547
Accessory: Door Interlock (Door Interlock Kit) DEH-41529
Accessory Retrofill Doors Assembly DEH-41563
Accessory: Position Switch Plate & Position Switch
Assembly & Wiring (Position Switch Kit)
Accessory: Neutral Rogowski CT Disconnect
(Neutral Assemblies)
Accessory: Programmer Disconnects DEH-41532
Accessory: Finger Clusters (Cluster Assemblies) DEH-41533
Accessory: Secondary Disconnects DEH-41534
FAQ DEQ-171
Application Guide DET-753
Guideform Spec DET-754
Spare/Renewal Parts Guide DET-755
DEH-41530
DEH-41531
Estimated Time to Complete Tasks
It takes about 20 minutes to install or replace the assembly.
General Description
When a legacy AK breaker is replaced with a retrofitted EntelliGuard ACB, the incoming wires from the neutral
CT’s need to be routed to the cassette secondary disconnects directly.
AKD-5—Neutral Disconnect Assembly (Breaker—N/A)
When a legacy AK breaker is replaced with a retrofitted EntelliGuard ACB, the incoming wires from the neutral
CT’s need to be routed to the cassette secondary disconnects directly.
AKD-5—Replace Iron Core Neutral CT with a Rogowski (Compartment)
The AKD-5 EntelliGuard R Circuit Breaker uses an open-core Rogowski current sensor to measure current level
vs. an iron-core style (Figure 1) used in the legacy AK, AKR breakers. For the retrofill to calculate the current levels on
a 4 wire circuit, the neutral iron-core CT in the cable compartment needs to be replaced with a Rogowski style CT.
The current transformer comes with the CT-mounted on copper bars matching the same hole-pattern as the existing
neutral bar. The existing wires can be reused. Note, if existing wires need to be replaced, then a continuous wire runs
from the CT to the neutral disconnect in the cubicle.
DEH-41531 02/12
Neutral Assemblies Manual
2
Figure 1. Neutral—AK25/50 Iron Core
Current Transformer Assembly
Neutral CT in Cable/Bus Compartment
• Turn off all power to switchgear. Tagout
and lockout main source, up-stream or
main breaker.
• Failure to comply with these instructions
will result in death or serious injury from
severe burns caused by arc flashing that
has exceedingly high temperatures.
• Always wear personal protection equipment
according to OSHA standards and appropriate
to the severity of potential burns.
• Ensure only qualified personnel install, operate, service, and maintain all electrical equipment.
Tools required: Wrenches, Wire stripper, wire cutter, continuity tester.
1. Ensure that the LVS has been de-energized and the breaker in the compartment, being retrofitted, are
switched off and removed from the LVS.
2. Open the door at the rear of the compartment to access the cable/bus compartment of the LVS.
3. Note that the existing neutral CT assemblies are usually mounted vertically on two copper bus bars
placed horizontally.
4. Make a note of the neutral disconnect assembly orientation and the polarity of the wire connections.
This is needed so that the same orientation is maintained when the new CT assembly is installed.
Neutral Assemblies Manual
3
DEH-41531 02/12
5. Disconnect the wires that are attached to the existing CT assemblies and place them in a way that they do not
interfere with the replacement of the CT assemblies.
6. Replace the neutral disconnect wiring with a new wire. This should be routed directly to the secondary disconnects of the cassette assembly.
7. Unfasten and remove the bolts that hold the neutral disconnects assemblies to the horizontal bus bars. Keep the
hardware in a handy location for reassembling.
8. Care should be taken while handling the CT assemblies such that they do not get damaged or damage other
components within the LVS.
9. Replace the old CT assembly with the new Rogowski assembly (Figure 2 or Figure 3, depending if it’s AK25 or
AK50 switchgear) on the horizontal bus bars and fasten it using the hardware previously removed. The position of
the new CT assembly should match that of legacy, noted during Step 4.
10. Connect the wires back to the Rogowski CT assembly leads. Maintain the same polarity as that of the legacy CT
connections, noted during Step 4.
11. Check for continuity from the CT leads to the secondary disconnects on the retrofit EntelliGuard ACB.
12. Always verify that the new Rogowski assembly is properly installed before activating it.
Figure 2. AKD-5—AK25 Neutral Bus Rogowski ASM 10108212
DEH-41531 02/12
Neutral Assemblies Manual
4
Loading...