Eaton’s molded case circuit breakers are designed to provide circuit protection for low voltage distributionsystems. They are described by NEMA as, “... a device for closing and interrupting a circuit between separable contacts under both normal and abnormal conditions,” and furthermore as, “... a breaker assembled as an integral unit in a supporting and enclosing housing of insulating material.” The National Electrical Code (NEC) describes them as, “A device designed to open and close a circuit by nonautomatic means, and to open the circuit automatically on a predetermined overload of current, without injury to itself when properly applied within its rating.”

So designed, Eaton circuit breakers protect conductors against overloads and conductors and connected apparatus, such as motors and motor starters, against short circuits.

In low voltage distribution systems, there are many varied applications of molded case circuit breakers. Eaton offers the most comprehensive family of molded case circuit breakers in the industry.

This section of circuit breakers includes:

• Thermal-magnetic trip breakers
• Electronic rms trip breakers
• Molded case switches
• Motor circuit protectors
• Current limiting breakers
• Special application breakers

Modified Breakers

Eaton breakers can be ordered with internal accessories installed. These modified breakers will be subject to an addition charge.

Special Calibration

Special non-UL listed calibrations are available for certain ambient temperatures other than 40°C and for frequencies other than 50/60 Hz or DC. Reduced interrupting ratings will apply for 400 Hz applications.

• Add suffix H01 to breaker catalog number for 400 Hz rating

50°C Calibration

Note: Breakers equipped with electronic trip units can operate reliably in ambient temperatures of 50°C. Add suffix “V3” to NG MCCBs to remove standard 40°C labeling.

Add suffix “V” to catalog number for complete thermal magnetic breaker when ordering listed ampere ratings for breakers to be used in 50°C ambients. 50°C ambient MCCBs are not UL listed.

Moisture-Fungus Treatment

All Eaton circuit breaker cases are molded from glasspolyester, which does not support the growth of fungus. Any parts that are susceptible to the growth of fungus will require special treatment.

Order by description.

• Add suffix J01 to breaker part number

Molded case circuit breakers are designed to conform with the following standards:

• Underwriters Laboratories Inc., Standard UL 489, molded case circuit breakers and circuit breaker enclosures
• National Electrical Manufacturers Association (NEMA) Standards Publication No. AB1-1993, molded case circuit breakers
• Australian Standard AS 2184, molded case circuit breakers
• British Standards Institution Standard BS 4752: Part 1, switchgear and control gear Part 1: circuit breakers
• Canadian Standards Association (CSA) Standard C22.2 No. 5, service entrance and branch circuit breakers
• International Electrotechnical Commission Recommendations IEC 60947-2, circuit breakers
• Japanese T-Mark Standard molded case circuit breakers
• South African Bureau of Standards, Standard SABS 156, Standard Specification for molded case circuit breakers
• Swiss Electro-Technical Association Standard SEV 157-1, safety regulations for circuit breakers

Internal Accessories

Alarm Lockout

The alarm switches operate when the circuit breaker is tripped by a short circuit or overcurrent, but also when it is tripped by a shunt trip or undervoltage release.

Auxiliary Switches

Auxiliary switches are used for signaling and control purposes.

Shunt Trips

The shunt trip is used for remote tripping.

The coil of the shunt trip is rated only for short-time operation.

It is not permissible with the circuit breaker open to apply a continuous opening command to the shunt trip in order to prevent the breaker from closing. This means that interlocking circuits with continuous commands may not be set up with shunt trips.

Undervoltage Releases

The circuit breaker cannot be closed until the undervoltage release is energized. If the release is not energized, the circuit breaker can only perform an idle switching operation.

Frequent idle switching actions should be avoided as they shorten the endurance of the circuit breaker.

Cause of Trip Display/Remote Mount Cause of Trip Display

The Cause of Trip Display can be field-installed on any Digitrip RMS 310+ trip unit. The device provides breaker information through an LCD screen, such as cause of trip, phrase current, ground current and low loads. The display is ideal for troubleshooting common trips such as ground fault, long delay, and instantaneous/short delay. The DIGIVIEW version will provide a local display at the breaker without additional wiring by connecting directly onto the trip unit. The DIGIVIEWR06 version has a 6 foot cable that allows users to mount the display on the outside of an enclosure door and connect to the trip unit that is contained inside the enclosure.