Main distribution panels are panel groups consisting of switchgear and control units directly supplied by the main electrical power source and designed to distribute and control electrical energy to consumers.
The main distribution boards are composed of functions that perform four main functions.
Power Distribution
Electrical Protection
Monitoring
Back up Power
1. Power Distribution
The first function of the main distribution is to connect the energy generated by the generators to the grid via the main switches. Generally in ships, 3 phase 400V AC which produced by generators. These energy collected in the main busbars are directed by the power control systems to the sub-distribution panels or directly to the consumers by usage of switches.
Circuit Breakers
The main Low Voltage Switch that is used to disconnect the electricity. Electricity can arc (jump) from the switches’ contact at high current. These switches are designed to safely disconnect the circuit.
Main Circuit Breakers
A circuit breaker can also be used to disconnect the site electrical supply. They perform the added Protection Function discussed below as well. This is not always an advantage and we will discuss this in the Electrical Protection section.
2. Electrical Protection
Abnormal incoming supply of electricity, if left unprotected, will damage equipment, may cause significate damage, fire hazard, and is a danger to the people on site. Issues that may arise are as follow:
- Short Circuit
- Overload
- Over Voltage
- Under Voltage
- Phase lost and Sequence
- Earth Leakage
- Surge Protection
3. Monitoring of Electricity Status and Quality
Through the special devices used, many electrical parameters such as power, voltage, current, active power, reactive power, harmonics of the main energy are displayed and managed according to these parameters. Measuring instruments are divided into two groups as analog and digital.
Digital Power Meter
Analog Power Meter
4. Backup Power to Prevent interruption of Power
There are many reasons why backup power should be activated. In case of a power failure (Block-out) for any reason, the vital devices that are required to operate continuously are automatically supplied by UPS or Emergency Generators.