Electric-GS is an experienced manufacturer of medium voltage and low voltage electrical equipment in Yueqing, Zhejiang, China. This guide is part of our engineering knowledge series to help buyers, engineers and contractors make correct decisions for power distribution projects.
What Is Low Voltage Switchgear?
Low voltage (LV) switchgear, also called LV switchboards or panels, controls and protects electrical circuits rated up to 1000V AC. It is the final distribution layer between transformers and end users, so its reliability directly affects every load in a building or factory.
Understanding the difference between withdrawable and fixed switchgear is the first step in LV panel selection.
Main Types of LV Switchgear
1. Fixed-Mounted LV Panels
All devices are mounted directly on frames. Low cost, simple, but maintenance requires de-energizing the section.
2. Withdrawable LV Panels
Breaker units can be pulled out for maintenance or replacement without shutting down the whole board. Ideal for continuous process industries.
3. Motor Control Centers (MCC)
Purpose-built for motor feeders, with contactors, overload relays and control wiring in modular buckets.
4. Distribution Boards
Compact boards for final sub-circuits such as lighting, sockets and small equipment.
Key Components Inside an LV Switchgear
- Main incoming breaker or switch
- Busbar system with insulation supports
- Molded case circuit breakers (MCCB) and miniature circuit breakers (MCB)
- Contactors and thermal overload relays
- Current transformers and metering
- Surge protection devices (SPD)
- Control and indication circuits
How to Select the Right LV Switchgear
| Selection Factor | What to Check |
|---|---|
| Voltage rating | 230V / 400V / 690V system |
| Main current | Transformer or feeder rating |
| Short circuit rating | Icw and Icc values |
| Form of separation | Form 1 to Form 4b |
| Degree of protection | IP31 indoor, IP54 outdoor |
| Environmental conditions | Humidity, temperature, altitude |
| Standards | IEC 61439-1/-2 compliance |
LV Switchgear for Solar and Industrial Applications
Solar farms need LV panels that combine inverter AC outputs and feed into step-up transformers. Our solar distribution panels include DC combiner capability, SPD protection and smart metering. See our guide on PV combiner box vs solar junction box for the DC side.
IEC 61439 Compliance Matters
Always specify panels built and tested according to IEC 61439. Type-tested designs guarantee temperature rise, short-circuit withstand and dielectric performance. Ask the manufacturer for test certificates before purchase.
FAQ About Low Voltage Switchgear
What is the difference between LV switchgear and LV switchboard?
They are essentially the same; switchgear often implies a higher fault rating and more sophisticated protection.
Can LV switchgear be installed outdoors?
Yes, with IP54 or higher enclosures, anti-corrosion treatment and suitable busbar arrangements.
What is Form 4b separation?
Form 4b separates busbars, functional units and terminals into individual compartments, allowing maintenance on one unit while others stay energized.
How long does an LV panel last?
20-30 years with proper maintenance and environmental control.
Do you supply custom LV panels for OEM clients?
Yes, Electric-GS is an OEM/ODM factory. We build to your drawings and brand, with full type test documentation.
What is the delivery time for LV switchgear?
Standard configurations ship in 15-30 days. Custom designs depend on complexity and certification.
LV Switchgear for Commercial Buildings: A Practical Example
For a 15,000 square meter shopping center, the typical LV installation uses two 2000A main distribution boards, twelve sub-distribution boards and more than eighty final circuits. The engineer must coordinate the main breaker rating with the transformer, the cable sizes with the fault levels, and the SPD protection with the building’s lightning risk category.
One mistake we often see in such projects is choosing Form 1 panels to save money, then discovering that any maintenance on one circuit forces a full building shutdown. Upgrading to Form 3b or Form 4b separation at the design stage usually costs only 10-15% more but saves far more in downtime over the building’s life.
Whether you are building a factory, a data center or a solar project, the same selection logic applies. Electric-GS can supply IEC 61439 certified LV panels in fixed or withdrawable versions, built to your single-line diagram. See how to choose between withdrawable and fixed switchgear, or browse our partner site electricgs.com for more products.
Busbar and Fault Level Coordination
The busbar system is the heart of an LV switchgear panel. For a 2500A main board, busbar cross-section is typically 3 x 100 x 10mm copper per phase, supported on insulators rated for the short-circuit withstand. Verify that the busbar bracing can handle the prospective fault current of your transformer, and that cable connections use the correct torque and contact compound.
It is equally important to coordinate breaker ratings: the incoming breaker must clear the transformer fault, while outgoing breakers must discriminate so only the faulty circuit trips. A discrimination study by your consultant is worth every cent. For the next steps in panel selection, read our withdrawable vs fixed switchgear guide, which explains how construction type affects maintenance and safety.
Testing LV Switchgear Before Delivery
A quality LV panel passes routine tests before it leaves the factory: visual inspection, mechanical operation tests of all breakers and switches, wiring verification against the schematic, insulation resistance measurement, and a high-voltage withstand test. Type tests according to IEC 61439 additionally cover temperature rise, short-circuit withstand and dielectric performance. Always request the routine test certificates and, for large projects, witness testing at the factory.
When panels arrive on site, repeat the mechanical and wiring checks, verify torque values after transport, and test all protection functions before energizing. A commissioning checklist with the responsible engineer’s signature prevents the embarrassing failures that appear only when the first load is connected. For more guidance on choosing the right construction, see our switchgear selection guide.
Always ask your switchgear supplier for the short-circuit withstand rating and the routine test certificates, and keep them with the panel documentation for the entire service life of the equipment.
About Electric-GS
Electric-GS is a professional OEM/ODM factory in Yueqing, Zhejiang, China, specializing in ring main units, gas insulated switchgear, vacuum circuit breakers, transformers, LV/MV switchgear and solar power distribution equipment. All products are manufactured with strict quality control and IEC standard testing. For quotations, drawings or customization, contact us at info@electric-gs.com or WhatsApp +86 135 8897 8050.