Views: 0 Author: Zhejiang Shengxian Electric Technology Co., Ltd Publish Time: 2026-06-23 Origin: Zhejiang Shengxian Electric Technology Co., Ltd
You receive a quote from a supplier with a long list of component names and model numbers. Do you know what each one does? Is the configuration appropriate, over-specified, or under-specified? Is it sufficient for your needs?
Many customers find it difficult to assess the configuration and end up making decisions based solely on the total price, which is the biggest risk.
This article provides you with a standard configuration framework for low voltage distribution panels, explaining:
What a distribution panel actually needs inside
How configurations differ across various panel functions
How to tell if a configuration is adequate, excessive, or insufficient
Regardless of its function, a standard low voltage distribution panel consists of the following components:
Component | Function |
|---|---|
Enclosure | Houses all components and provides protection (steel with powder coating) |
Main busbars | Run through the entire assembly, carrying the total current (copper) |
Branch busbars | Tap power from the main busbars to supply each outgoing circuit |
Switching devices | Circuit breakers, disconnectors – for switching and protection |
Secondary components | Instruments, indicator lights, push buttons, instrument transformers – for control and indication |
Terminal blocks | For connecting incoming and outgoing cables |
A complete low voltage distribution system typically consists of a combination of the following panel types. Which ones you need, and how many of each, depends on the number of incoming sources, outgoing circuits, and whether power factor correction is required.
Incoming Panel
Function: Receives power from the transformer or generator and distributes it to the busbars
Key components: Air circuit breaker (ACB) or high-current molded case circuit breaker (MCCB), current transformers, voltmeter, ammeter, surge protective device
Selection notes: The ACB's rated current and breaking capacity must match the transformer capacity
Outgoing Panel
Function: Distributes power to end loads (motors, lighting, air conditioning, sockets, etc.)
Key components: MCCBs or MCBs, contactors (for remotely controlled circuits), thermal overload relays (for motor circuits), current transformers
Selection notes: Each outgoing circuit must have independent protection so a fault affects only that circuit
Bus Coupler Panel
Function: Connects two busbar sections for dual-source backup or load transfer (used in dual-transformer systems)
Key components: ACB, current transformers, interlocking devices
Selection notes: Must include both mechanical and electrical interlocks to prevent parallel operation of the two sources
Power Factor Correction Panel
Function: Automatically switches capacitors in and out to improve power factor and reduce electricity costs
Key components: Intelligent controller, capacitors, contactors or thyristor switches, reactors (for harmonic environments), fuses
Selection notes: Compensation capacity is typically sized at 30–40% of the transformer capacity
Below is a typical configuration checklist for a low voltage outgoing panel:
No. | Component | Specification | Qty |
|---|---|---|---|
1 | Enclosure | Steel plate ≥2.0mm, powder coated | 1 set |
2 | Main busbars (copper) | Sized per rated current | 1 set |
3 | Branch busbars (copper) | Sized per circuit current | 1 set |
4 | MCCBs | Sized per circuit current | N units |
5 | Current transformers | Matched to breaker current | N units |
6 | Digital ammeter | 3-phase current display | 1 unit |
7 | Voltmeter + selector switch | 3-phase voltage display | 1 set |
8 | Indicator lights (red/green) | On/off indication | As required |
9 | Push buttons (on/off) | Manual operation | As required |
10 | Terminal blocks | For control wiring connections | 1 set |
11 | Internal lighting | For maintenance access | 1 set |
12 | Earth busbar | Safety earthing | 1 set |
Project Type | Enclosure IP Rating | Incoming Panels | Outgoing Panels | Correction Panel | Bus Coupler |
|---|---|---|---|---|---|
Small factory | IP30–IP40 | 1 | 3–6 | Optional | Usually not required |
Medium factory | IP40 | 1–2 | 6–10 | 1 | Required for dual incoming |
Commercial building | IP30 | 1 | 4–8 | 1 | Usually not required |
Residential project | IP30 | 1 | 2–4 | Usually not required | Not required |
Export project | IP54 | As required | As required | As required | As required |
Assessment | Description | |
|---|---|---|
Insufficient | Missing essential protection devices, or components are undersized | Risk of tripping, overheating, and burnout |
Excessive | Components are over-specified for actual needs, adding unnecessary cost | Wasted money |
Adequate | Component ratings meet current needs with room for 2–3 years of growth | Best value |
Recommendation: When you receive a quote, compare it against this checklist. Be cautious of quotes that are missing key components – and ask for justification if you see unnecessary features being added.
There is no one-size-fits-all configuration for distribution panels – every project is different. But the principles of a good configuration are universal: proper protection, safe operation, easy maintenance, and appropriate sizing.
Next time you receive a quote, check it against this list:
Does the incoming panel include a surge protective device?
Does each outgoing circuit have its own independent MCCB?
Does the correction panel come with an automatic controller, or is it manual?
If you are unsure what configuration your project needs, send us your project details. We will provide a customized configuration checklist based on: transformer capacity, number of outgoing circuits, load types, and installation environment.
Need a custom configuration? Contact us.
Web: https://yqsxdl.en.made-in-china.com/
Whatsapp：+86 195 1818 9858
Mail: lunahe927@gmail.com/19518189858@163.com
