Medium Voltage Metal Clad
Medium Voltage Metal Clad

Cutler-Hammer has been manufacturing metal-clad switchgear for over 50 years, and vacuum circuit breakers for over 30 years. Tens of thousands of Cutler-Hammer vacuum circuit breakers, used in a wide variety of applications, have been setting industry performance standards for years. With reliability as a fundamental goal, Cutler-Hammer engineers have simplified the VCP-W switchgear design to minimize problems and gain trouble-free performance. Special attention was given to material quality and maximum possible use was made of components proven over the years in Cutler-Hammer switchgear. Maintenance requirements are minimized by the use of enclosed long-life vacuum interrupters. When maintenance or inspection is required, the component arrangements and drawers allow easy access. VCP-W's light weight simplifies handling and relocation of the breakers. VCP-W meets or exceeds all applicable ANSI, NEMA, and IEEE design standards, and additionally offers many outstanding safety features. To ensure reliability and quality, the testing of VCP-W switchgears has been extensive. UL and CSA listed switchgear is also available.

Application Description

Cutler-Hammer VCP-W metal-clad switchgear with type VCP-W vacuum breakers provides centralized control and protection of medium voltage power equipment and circuits in industrial, commercial, and utility installations involving generators, motors, feeder circuits, and transmission and distribution lines. VCP-W switchgear is available in maximum voltage ratings from 4.76 kV through 38 kV, and interrupting ratings as shown below. VCP-W offers a total design concept of cell, breaker, and auxiliary equipment, which can be assembled in various combinations to satisfy user application requirements. Two-high breaker arrangements are standard up to 15 kV. One-high arrangements can be furnished when required.

Features, Benefits and Functions


High power laboratory tests prove VCP-W breakers are capable of 50 to 200 full fault current interruptions.

Space Savings

Up to 50% floor space reduction over previous designs.

Vacuum Interrupter, Current Transfer Conductor

The Cutler-Hammer stiff-flexible design eliminates sliding/rolling contacts in the main conductor which provides excellent electrical and thermal transfer and long vacuum interrupter life.

Grounded Steel Safety Shutters

Prevents accidental contact with live primary voltage connections when breaker is withdrawn.

Breaker Rails

On 5 - 27 kV units the breaker can be withdrawn on rails for inspection and maintenance without the need for a separate lifting device.


38 kV breaker is designed to roll directly on the floor.

Reduced Breaker Weight

525 Ibs. (238.4 kg) maximum through 27 kV vs. 2450 Ibs. (1112.3 kg) in a comparable air-magnetic design for ease of handling.

Reduced Breaker Maintenance

Vacuum interrupter requires only periodic check for contact erosion. Integral wear indicator provided. No contact adjustments are required.

Front Accessible Mechanism

Front accessible mechanism is standard on all VCP-W breakers.

Front Accessible CTs (5-27 kV)

Up to 12 CTs per breaker can be mounted for easy access.

Drawout Auxiliary Compartments

Up to 4 drawers per vertical section can be equipped with CPTs or VTs up to 15 kV. Primary isolation shutters are standard.

Fluidized Bed Epoxy Bus Insulation

Excellent track resistant and flame retardant properties.

Standardized Functional Designs

Shortens order cycle time.

Protective Relays

A full scope of protective relays designed to meet all application requirements is available to provide the utmost in system and component protection. One such multi-purpose relay system is the Cutler-Hammer Digitrip 3000. This microprocessor-based circuit protective, control and monitoring relay system includes devices 50, 51, 50N, 51N, 50G, 51G and 86, plus cause and magnitude of trip, integral test and programming, ampere demand, high load alarm, non-volatile set-points, self-testing and communications capabilities. The Digitrip 3000 is capable of being monitored and controlled through the Cutler-Hammer PowerNet System and other monitoring/control packages. The Digitrip 3000 is further discussed elsewhere in this publication.

PowerNet - Integrated Monitoring Protection and Control Communications System

Medium-voltage VCP-W switchgear is ideally suited for the unique Cutler-Hammer PowerNet System. PowerNet is the unique system that, for the first time, ties together multiple devices in electrical distribution systems in a wide variety of buildings and plants. PowerNet utilizes the proven, INCOM chip for highly reliable, two-way communications (even in noisy industrial environments) between the master control unit and system devices via a twisted pair of conductors. Communications wires can be extended up to 10,000 feet from the master control unit without repeaters... and as many as 1,000 compatible devices, installed in various assemblies, can be on the PowerNet System.

Easy Installation

Installation is uncomplicated and devices are connected, daisy chain style, via the twisted pair conductors. All assemblies and devices are standard Cutler-Hammer equipment when PowerNet compatible devices are ordered as part of an assembly. The assemblies (with compatible devices built in) are prewired, pretested and delivered complete.


PowerNet is flexible in that it can include those assemblies, such as VCP-W switchgear, that are desired in a distribution system...but PowerNet can be easily upgraded as new assemblies are added. In essence, a customer determines the requirements for a building's electrical distribution system, and Cutler-Hammer provides the PowerNet System to fit those specific requirements.