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Instruction Book
IB182012EN March 2017 www.eaton.com
50DH-VR-50AXU / 50XU / 75U / 75ARU - 600 / 1200A
Replacement Circuit Breaker
SECTION 1: INTRODUCTION
The purpose of this book is to provide instructions for receiving and
handling, storage, installation, operation and maintenance of type
50DH VR-Series circuit breaker. The Vacuum Replacement Circuit
Breakers (also referred to as VR-Series) are designed to be used
in existing Westinghouse type 50DH metal-clad switchgear and
provide equal of superior electrical and mechanical performance
as compared to the design ratings of the original circuit breaker.
VR-Series circuit breakers provide reliable control, protection and
performance, with ease of handling and maintenance. Like ratings
are interchangeable with each other.
This book is intended to be used in conjunction with the technical
information provided with the original equipment order which
includes, but is not limited to electrical control schematics and wiring
diagrams, outline diagrams, installation plans, and procedures for
installation and maintenance of accessory items.
Satisfactory performance is dependant upon proper application,
correct installation, and adequate maintenance. It is strongly
recommended that this instruction book be carefully read and
followed in order to realize optimum performance and long useful life
of the circuit breaker.
Circuit breakers manufactured for DH switchgear fall into two distinct
types: Front Racking and Rear Racking. Front racking circuit breakers
(Types 50-DH-VR-50 AXU and 75U) have arms that cam the circuit
breaker into the circuit breaker positioned toward the front sides of
the circuit breaker. The Rear racking circuit breakers (Types 50-DH-
VR-50 XU and 75RU) have these arms located at the rear sides of
the circuit breaker. These two configurations are not interchangeable.
The correct type must be specified during order entry.
WARNING
SATISFACTORY PERFORMANCE OF THESE CIRCUIT BREAKERS IS
CONTINGENT UPON PROPER APPLICATION, CORRECT INSTALLATION
AND ADEQUATE MAINTENANCE. THIS INSTRUCTION BOOK MUST BE
CAREFULLY READ AND FOLLOWED IN ORDER TO OBTAIN OPTIMUM
PERFORMANCE FOR LONG USEFUL LIFE OF THE CIRCUIT BREAKERS. IT IS
FURTHER RECOMMENDED THAT THE INSTALLATION BE PERFORMED BY
AN EATON TRAINED ENGINEER OR TECHNICIAN.
VR-SERIES CIRCUIT BREAKERS ARE PROTECTIVE DEVICES, AS SUCH, THEY
ARE MAXIMUM RATED DEVICES. THEREFORE, THEY SHOULD NOT UNDER
ANY CIRCUMSTANCE BE APPLIED OUTSIDE THEIR NAMEPLATE RATINGS.
ALL POSSIBLE CONTINGENCIES WHICH MIGHT ARISE DURING
INSTALLATION, OPERATION, OR MAINTENANCE, AND ALL DETAILS
AND VARIATIONS OF THIS EQUIPMENT ARE NOT COVERED BY THESE
INSTRUCTIONS. IF FURTHER INFORMATION IS DESIRED BY THE
PURCHASER REGARDING A PARTICULAR INSTALLATION, OPERATION, OR
MAINTENANCE OF THIS EQUIPMENT, THE LOCAL EATON REPRESENTATIVE
SHOULD BE CONTACTED.
1.1 AVAILABLE 50DH-VR CIRCUIT BREAKERS
Refer to Table 1.
Table 1. 50DH-VR Availability and Interchangeability
Circuit Breaker
Type
ab
Nominal
Voltage
Class
Existing
Circuit
Breaker
Rating
Existing Circuit
Breaker Rated
Continuous
Current at 60 Hz
VR-Series
Circuit
Breaker
Rating
Rated
Voltage
Factor
Rated Withstand
ANSI Test Voltage
Rated
Short-
Circuit
Maximum Sym.
Interrupting Capability
Closing and Latching /
Momentary Capabilities
kV
MVA
Amps
MVA
K
Low Freq.
kV RMS
Impulse
kV Peak
I
kA RMS
KI
kA RMS
kA RMS / Peak
50DH-VR
4.16
50
600 / 1200
150
1.0
19
60
52
4.16
75
600 / 1200
150
1.0
19
60
52
a
DH-VR circuit breaker nameplates are printed according to sales order requirements; the ratings may differ from the values in Table 1.
b
Available as front racking or rear racking.