Brochure

PowerPact H-, J-, and L-Frame Circuit Breakers

Trip Units

02/2016

Section 7—Trip Units

Available Trip Units

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PowerPact™ H-, J-, and L-Frame circuit breakers offer a range of thermal-magnetic and

Micrologic™ electronic trip units in interchangeable cases. Thermal-magnetic trip units are

designed to open automatically under overload or short circuit. H-frame and J-frame thermal-

magnetic circuit breakers contain individual thermal (overload) and instantaneous (short circuit)

sensing elements in each pole.

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Micrologic electronic trip units provide intelligent operation, with wide setting ranges make

installation upgrades easier. Designed with processing capabilities, Micrologic trip units can

provide measurement information and device operating assistance to supply all of the information

required to manage the electrical installation and optimize energy use.

Micrologic trip units offer excellent measurement accuracy, using a new generation of current

transformers combining “iron-core” sensors for self-powered electronics and “air-core” sensors

(Rogowski coils) for measurements. The protection functions are managed by an ASIC component

that is independent of the measurement functions. This independence ensures immunity to

conducted and radiated disturbances and a high level of reliability.

An LED on the front of the electronic trip units indicates the result of the self-test running continuously on

the measurement system and the tripping release. When the green LED is flashing, the links between

the CTs, the processing electronics and the Mitop release are operational. The circuit breaker is ready

to protect. A minimum current of 15 to 50 A, depending on the device, is required for this function.

The dual adjustment for protection functions on Micrologic 5/6 consists of:

— an adjustment using rotary switches sets the maximum value

— an adjustment, made using the keypad or remotely, fine-tunes the setting. This setting may not

exceed the first one. It can be read directly on the Micrologic screen, to within one ampere and

a fraction of a second.

NOTE: All the trip units have a transparent sealable cover that protects access to the adjustment

rotary switches.