ACB is an abbreviation for Air Circuit Breaker. As the name suggests, this electrical device uses compressed air to break the flow of current and protect electrical circuits from excessive current due to overload or short circuit.
Usually, ACB is more suitable for use on larger systems or loads. This is because ACB has a current rating of up to 6300 A. The current rating itself is the amount of current needed for the device to operate. This circuit breaker can also be used in places with a higher risk of fire or explosion.
ACB is usually used to protect electricity sources. This device has category B, where the ACB will not immediately cut off the current when the current exceeds the threshold limit. However, ACB can last for several milliseconds, which can stabilize the device and reduce the potential for damage to the connected load.
Siemens ACB is one of the electrical devices that you can rely on because it can protect energy distribution optimally from system shutdowns, failures, and consequential costs.There are two types of Siemens brand ACB that are commonly used, namely 3WL Air Circuit Breakers Siemens and 3WT Air Circuit Breakers Siemens.
There are two types of Siemens brand ACB that are commonly used, namely 3WL Air Circuit Breakers Siemens and 3WT Air Circuit Breakers Siemens.
- 3WL Air Circuit Breakers, Siemens
- Mechanical ON and OFF buttons
- Manual operating mechanism with mechanical closure
- Auxiliary switch: 2 NO + 2 NC
- Rear horizontal main circuit connection for fixed-mounted version and withdrawable version up to 5000 A, and rear vertical main circuit connection for 6300 A and size II applications with 4000 A
- For a 4-pole (4P) circuit breaker, the fourth pole (N) is installed on the left and can be 100% loaded with the rated current.
- There is a contact erosion indicator for the main circuit.
- Mechanical “disconnected” indicator for electronic breaker systems (Circuit Breaker Electronic)
- The operator panel cannot be disconnected together with the circuit breaker when it is in the ON position.
- In fixed-mounted versions, the additional mounting connector is attached directly to the circuit breaker. The connector is also equipped with coding pins, which prevent them from being accidentally swapped.
- In withdrawable versions, the internal auxiliary switch is connected to the male connector on the side of the switch. When fully inserted, the connector makes a connection with the sliding contact module in the guide frame. Various adapters can then be used to complete the cable installation.
There are two types of ACB Siemens 3WL Air Circuit Breakers, namely 3WL Air Circuit Breakers Fixed Versions and 3WL Air Circuit Breakers Withdrawable Versions.
For 3WL Air Circuit Breakers Withdrawable Versions Siemens, there are several additional features, such as:
- Laminate housing in guide frame, blade contact on withdrawable circuit breaker
- There is a position indicator on the operator panel.
- Retractable manual crank handle to actuate retractable circuit breakers
- Guide frame with guide rails for easy movement
- ACB Siemens 3WL Withdrawable versions can be locked to prevent being pushed out of position.
- ACB Withdrawable Versions cannot be moved when in the ON position.
- Encoding the measured current between the guide frame and withdrawable circuit breakers
- 3WT Air Circuit Breakers Siemens
- Protective measures against arc-causing gases
- Additional electrical devices on the circuit breaker side must be closed separately.
- The operator panel is designed to protrude from the door cutout, providing access to all operator controls, and can be displayed with the door closed.
- The operator panel for ACB (fixed or withdrawable with 3P or 4P) is similar.
- There is a door sealing frame, which will seal the cabinet door with the operator panel. With a closed cabinet, an IP level of protection will be achieved for the circuit breakers.
- In 3WT Air Circuit Breakers Fixed-mounting Versions, the additional supply connector is connected directly to the circuit breaker.
- Meanwhile, in the Withdrawable Versions type, the internal auxiliary switch is connected to the male connector on the side of the circuit breaker. When fully inserted, the connector will make a connection with the sliding module in the guide frame.
Just like the Siemens 3WL ACB, 3WT also has two types, namely 3WT fixed-mounted versions and 3WT withdrawable versions.
On the 3WT Air Circuit Breakers Withdrawable Versions Siemens, there are several different additional features, namely:
- There is a hand crank to move the device.
- The guide frame is equipped with guide rails as standard to facilitate the handling of ACB withdrawable versions.
- Auxiliary supply connections will make contact automatically when the circuit breaker slides into the guide frame (test position, connected position).
- ACB 3WT Withdrawable Versions have three switch positions in the switch equipment cabinet behind the cabinet door.
- Connected Position: The main circuit and auxiliary circuit are ready.
- Test position (test position): The main circuit is disconnected and the auxiliary circuit is ready.
- Disconnected Position: The main circuit and auxiliary circuit are disconnected.
In the disconnected position, Circuit Breakers Withdrawable Versions comply with “protective separation conditions” with visible isolation distances on the main circuit and auxiliary circuit. The breaker should always be turned off before moving. The “OFF” button must also be pressed when the slide in the crank hole is opened.
