ABB UL 489 and CSA C22.2 Standard molded case circuit breakers

ABB UL 489 and CSA C22.2 Standard  molded case circuit breakers

COMPLETE AND PERFECTLY INTEGRATED

In the range of molded case circuit breakers conforming with the UL 489 and CSA C22.2 Standard, ABB proposes an entire range which covers current ratings between 15 A and 2500 A and interrupting ratings, at 480 V AC, which can reach 150 kA.

The ranges available are as follows: 

– circuit breakers for power distribution (fitted with thermomagnetic or electronic trip units starting from 100 A) 

– circuit breakers with adjustable magnetic only trip units for motor protection (MCP: Motor Control Protection) 

– molded case switches for use as isolators or switching devices for lines, busbars or parts of a plant (MCS: Molded Case Switch)

COMPACT DIMENSIONS

ABB molded case circuit breakers ensure high performances in extremely small and compact dimensions. Standardization of the depth of the smaller sizes allows more rational and less deep enclosure to be used than in the past.

DOUBLE INSULATION

Thanks to the double insulation technique, with all ABB molded case circuit breakers* the electrical accessories can be mounted directly on field with the circuit breaker installed: this allows considerable savings in time and therefore in costs.

ALL THE APPLICATIONS

ABB offers the right solution for any application up to 2500 A thanks to Isomax S6, S7 and S8 circuit breakers, perfectly integrated with the Tmax family:

– MCCB: S6, S7 and S8 molded case circuit breakers for power distribution; 

– MCP: S6, S7 and S8 circuit breakers with magnetic only trip unit for motor control protection; 

– MCS: S6, S7 and S8 molded case switches for using as isolators or switching devices for lines, busbars or parts of plants.

COMPLETE RANGE OF ACCESSORIES

Isomax circuit breakers are complemented by a complete range of accessories to satisfy the widely differing operational and automation requirements. Accessories are standardized for groups of circuit breakers to streamline storage logistics and simplify installation. Isomax circuit breakers can be customized as required under conditions of absolute safety. All the accessories can be mounted with simple operations without exposing the main contacts (except for the Isomax S8).

Starting from the fixed version circuit breaker, all the other versions used for various requirements are obtained by means of mounting conversion kits. The following are available: 

– kit for converting a fixed circuit breaker into the moving part of a plug-in and draw out one 

– circuit breaker fixed parts for plug-in and draw out circuit breakers 

– conversion kit for the connection terminals.

Double insulation

This construction characteristic consists of the presence of double insulation between the live power parts (excluding the terminals) and the front parts of the apparatus where the operator works during normal operation of the installation. The seat of each electrical accessory is completely segregated from the power circuit, thereby preventing any risk of contact with live parts, and, in particular, the operating mechanism unit is completely insulated in relation to the powered circuits. As a consequence most accessories are field installable. Furthermore, the insulation distances, both between the live internal parts and in the terminal connection area, comply with what is foreseen by the UL 489 Standard and are higher than those required by the international IEC Standards.

Positive operation

The operating lever always indicates the exact position of the circuit breaker moving contacts, thereby guaranteeing safe and reliable signals in compliance with the prescriptions of the IEC 60417-2 Standard (I = Closed; O = Open; yellow-green line = Open due to release trip). The circuit breaker operating mechanism has trip free operation. Trip unit intervention automatically opens the moving contacts: to close them again, the operating mechanism must be reset by pushing the operating lever from the intermediate position into the lowest open position.

Operating temperature

The Tmax and Isomax circuit breakers can be used in ambient conditions where the surrounding air temperature varies between –13 °F and +158 °F (–25 °C and +70 °C) and stored in ambient with temperatures between –40 °F and + 158 °F (–40 °C and +70 °C). The circuit breakers fitted with thermomagnetic trip unit have their thermal element set for a reference temperature of 104 °F (40 °C). For temperatures other than 104 °F (40 °C), with the same setting, there is a variation of the thermal threshold as shown in the tables on page 4/36 and 4/37.