Modelling a source in ElectricalOM NEC-IN
Introduction
ElectricalOM NEC-IN is a powerful electrical design software that allows users to model complex electrical systems effortlessly. To build a project, users can add components and connect them using the Insert menu. This feature can be accessed in several ways: by clicking on the Actions Menu in the Menu Bar, right-clicking anywhere within the Schematic Module’s drawing area, or interacting with the System Tree Section.
Starting a New Project: Inserting the Source
Every new project begins by inserting a Source. ElectricalOM NEC-IN offers three types of sources to choose from:
- 3Ph+N (Three-phase plus neutral)
- 1Ph+N (Single-phase plus neutral)
- DC Source (Battery)
After selecting the type of source, ElectricalOM NEC-IN will name it as “Supply” and place it in the Schematic Module’s drawing area. To modify the Source properties, double-clicking on either the source icon in the schematic or its name in the System Tree Section will bring up the Edit Source window.
Customizing the Source Component
The Edit Source window offers various customization options grouped into four key tabs:
- Source Properties
- Earthing
- LV Protection Device
- Premises & Diversity
- High Voltage Settings
ElectricalOM NEC-IN supports the insertion of multiple sources. However, unless parallel operation is activated, only one source can be active at a time. Each time a new source is inserted, it automatically becomes active while others are deactivated, with deactivated sources shown as greyed-out symbols. The user can activate a different source via the right-click menu by selecting the Activate option.
Supported Components for the Source
A source component only supports a few types of connected components, while other components will be greyed out in ElectricalOM NEC-IN. The compatible components include:
- Switch Board
- Distribution Board
- Busbar Trunking System
- Junction Box
- Transfer Switch
Source Properties Tab
The Source Properties tab contains critical configuration options related to supply voltage, earthing systems, frequency, and voltage drop limits. Depending on whether the source is single-phase or three-phase, ElectricalOM NEC-IN will adjust the voltage settings. The user can enter the voltage between phase and neutral (for single-phase) or between two phase terminals (for three-phase).
Earthing Systems and Frequency
The earthing system offers three options:
- TN
- TT
- IT
If TN is selected, two additional choices become available: TN-C-S and TN-S.
Supply frequency options include:
- 50Hz
- 60Hz
Voltage Drop Limits
The system allows users to set maximum values for voltage drop from the origin of the installation. The following three options are available:
- Public Supply (3% for lighting circuits, 5% for others)
- Private Supply (3% for lighting circuits, 5% for others)
- User-Defined Limit (Manually set value, applied to all circuits)
Middle Section: Source Type and Characteristics
The middle section of the Source Properties tab is dedicated to the source type and its characteristics. Depending on the selected source type, different supply methods and source characteristics may appear. ElectricalOM NEC-IN caters to various types of sources, including those specific to the Cyprus market. However, it’s crucial to avoid using these for projects outside Cyprus.
Key options include:
- Low voltage (400V/230V) from a sub-station with max transformer rating 1000kVA
- Low voltage (400V/230V) parallel operation of two transformers
- Low voltage (400V/230V) exclusive customer supply
- User-defined source: Enables full customization of power, transformer impedance, and fault current calculations.
Transformer and Generator
If the user selects the Transformer
option, additional settings related to primary voltage and fault impedance will
appear, allowing for more detailed calculations such as load capacity in
amperes.