Protection Devices | Enclosure Solutions

Contents
- MCB Characteristics
- RCD Characteristics

See "Contents II" below 4 Item specifics

MCB Characteristics

1. MCB Model name
2. Nominal Current (In)
3. Operating Voltage (VAC)
4. Tripping Characteristic
5. Breaking Capacity (Icn)
6. I2t Classification (Energy Limitation)
7. Circuit diagram (Number of poles)

The tripping characteristics of MCB'S

The MCB disconnection is performed by two difference releases. The instantaneous tripping by electro-magnetic release provides protection against short circuits & Thermal bi-metal release provides protection against overloads. They should disconnect automatically as soon as the combination of the current rise and duration causes the cable or a component to heat up excessively.
There are different tripping characteristics available for MCBs, depending on the application the suitable characteristic must be chosen.

RCD Characteristics

1. RCD Model Name
2. Rated Current (In)
3. Rated Residual Operating Current (IΔn)
4. Rated Voltage (Un)
5. Rated Making & Breaking Capacity (Im)
6. Contact Position Indicator
7. Wiring Diagram
8. ABB Identity Number
9. Test Button

Types of waveform detected by RCD's & classification

RCD Characteristics

• 30 mA instantaneous RCD
• 30 mA APR (anti-disturbance) instantaneous RCD
• 300 mA selective RCD (type S)

* Type S RCDs have a delayed tripping action and are installed upstream of other rapid RCDs to guarantee selectivity and limit the power out only to the portion of the system affected by a fault.

* APR devices which trip according to the limit times allowed by
the Standards for instantaneous RCDs.

MCB Contents II

Contents II

A. Domestic Range

A1. Switch Disconnectors

>>>Notes: SHD.. E20..