For complete electrical assembly with wiring, customers must provide primary (single line) and secondary wiring diagrams.
Professional OEM Electrical Panel Wiring, Control Cabinet Assembly, and Metal Enclosure Fabrication.
At Vililong, we provide end-to-end electrical assembly and panel assembly services for power distribution, industrial automation, machinery control, and energy systems.
All panels are factory pre-wired, fully tested, and ready to install, helping contractors, integrators, and equipment manufacturers reduce on-site labor and project costs.
With in-house sheet metal fabrication and strong OEM capability, we deliver complete solutions—from empty enclosure fabrication to full electrical assembly.

Assembly Process
1.Customer Inquiry
Provide enclosure type, specifications, and overall project requirements, including application, installation environment, and preferred components.
Our team reviews the basic information to determine the suitable enclosure and assembly approach.
2.Technical Documentation
Submit the single-line diagram (SLD), wiring diagram, layout drawing, and BOM list for evaluation.
We check completeness, confirm wiring routes, and verify compatibility of components and enclosure size.
3. Engineering Review
Our engineers analyze technical details, component specifications, and assembly standards required for the project.
If needed, we optimize layout, cable entry positions, and internal space to ensure efficient wiring and installation.
4. Quotation & Confirmation
We prepare a detailed quotation based on drawings, BOM, material selection, wiring complexity, and testing requirements.
All pricing covers enclosure fabrication, component installation, wiring, labeling, and quality control.
5. Fabrication & Electrical Assembly
Metal enclosure fabrication is completed first, including cutting, bending, welding, powder coating, and pre-cut openings.
Then we perform component installation, DIN-rail mounting, terminal block setup, cable routing, and full internal wiring.
6. Testing & Final Inspection
All wiring is completed strictly according to diagrams, with cable labeling, ferrules, and professional cable dressing.
Each panel undergoes continuity testing, function testing, torque checks, and a full final inspection before packing.
Our Electrical Assembly Capabilities
1. Electrical Panel Assembly (Turnkey Service)
We provide complete turnkey panel assembly based on your drawings and BOM, covering DB boards, control cabinets, automation panels, and custom electrical systems.We assemble a wide range of electrical panels based on customer drawings, BOMs, or samples, including:
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Distribution boards (DB boards)
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Control panels & automation cabinets
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Junction boxes and control stations
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Terminal boxes
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MCC/PLC/HVAC panels
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Energy storage & inverter panels
Our assembly scope includes:
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DIN rail mounting
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Terminal block wiring
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Cable routing & cable dressing
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Component installation (MCB, MCCB, relays, meters, switches)
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Labeling & numbering
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Electrical testing and function check
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Earthing & grounding
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Final inspection and packaging
Whether you need a single prototype or batch production, we offer flexible OEM solutions.
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2. Pre-Wired & Factory-Tested Solutions
Our panels are factory pre-wired, fully tested, and ready to install, helping contractors reduce on-site labor, improve wiring quality, and shorten project timelines.Many global customers choose our factory pre-wired panels to minimize installation time.
Benefits of pre-wired panels include:
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Reduce on-site wiring time by 40–60%
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Minimize installation errors
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Stable wiring quality and consistency
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Faster commissioning
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Lower labor cost for contractors
Every assembled panel is fully inspected before delivery, following IEC/CE standards.
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3. Metal Enclosure Fabrication (In-House Sheet Metal)
We fabricate all enclosures in-house—laser cutting, bending, welding, and powder coating—to deliver durable, custom-fit cabinets for any electrical assembly project.Unlike typical panel assembly companies, we also manufacture metal enclosures in-house.
This allows us to provide a true one-stop enclosure + assembly service.Our fabrication capability includes:
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Laser cutting
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CNC bending
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Welding & grinding
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Powder coating
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Rittal-compatible enclosure manufacturing
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Custom cutouts & pre-punching
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Stainless steel, galvanized steel, cold-rolled steel
We produce wall-mounted enclosures, floor-standing cabinets, distribution boxes, ES/PS series, and custom control panels.
This integration helps customers reduce cost and lead time significantly.
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4. OEM / ODM Electrical Assembly Service
We support OEM and ODM manufacturing with flexible customization, component selection, labeling, and neutral branding for distributors and equipment manufacturers.We support OEM and ODM manufacturing for:
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Electrical brands
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Solar/inverter companies
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Machinery manufacturers
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Panel builders
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Electrical distributors
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EPC contractors
Just provide your drawings, wiring diagram, BOM, or reference sample, and we take care of the rest.
Neutral branding or customer branding is also available.-
5. Quality Control & Testing
We conduct full QC and electrical testing—continuity, functional checks, torque inspection, earthing verification, and wiring review—to ensure stable performance and compliance with IEC/CE standards.-
Continuity testing
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Functional testing
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Component inspection
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Torque check
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Earthing verification
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Visual inspection for wiring quality
We follow IEC, CE, and customer-specific standards to ensure reliability and safety.
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Industries We Serve
Why Choose Us
FAQs About Electrical Assembly & Panel Assembly
1.What documents do you need to start electrical assembly?
We can assemble based on your wiring diagram, BOM list, layout drawing, or reference sample. If you only have a concept, we can also assist with layout design.
2. Can you fabricate the metal enclosure and assemble the components together?
Yes. We provide both enclosure fabrication and full panel assembly in one factory—saving cost and production time.
3. Do you offer pre-wired or ready-to-install panels?
Yes. All panels can be factory pre-wired, labeled, tested, and delivered ready for installation at the job site.
4. What testing do you perform before shipment?
We provide continuity tests, function tests, torque checks, visual inspection, and quality verification based on IEC/CE requirements.
5. Can you assemble panels with customer-specified brands?
Yes. You can specify Schneider, ABB, Eaton, LS, CHINT, or any brand you prefer. We also support mixed-brand assembly.
6. What is your minimum order quantity?
No strict MOQ. We accept prototype orders, small runs, and mass production for OEM customers.
Professional Electrical Enclosure &
Prefabricated Assembly Manufacturer
Your Reliable Partner for Power Distribution and Automation Solutions
Tell us your enclosure or assembly needs — our team will respond within 24 hours.
What’s your company main products?
The main business is to provide customers with custom enclousure services, we also sell some General Boxes.
How about the price of the product?
We are a manufacturer, we mainly provide customized services for our customers, and we believe that our prices have enough advantages.
What does the enclosure customization service contain?
Box Sizes,Box Colors,Door Types,Gland Plates,Specific Cutouts,Moutning Plates,Protective Covers,Standing Types,Windows,Thickness,Accessories.
Can we get the sample? Is it free?
Yes, we could offer the general box sample for free charge,but need you pay the express. The freight depends on weight, packing size and your country or province region, etc.
What’s about MOQ?
First order MOQ=1pcs.
How can I get product catalogs?
You can get the catalogs by contacting us.
How to order our product?
1.Please tell us the model and quantity and other request you need.
2.We make the PI for you.
3.After you confirm the PI, we arrange the order for you after receiving your payment.
4.After the goods finished, we send the goods out to you and tell you the tracking number.
5.We will track your goods until you receive the goods.
How about the after-sale service?
If you meet any problems after sales, pis contact us freely, we’ll help solving the problems within 24 hours.
What’s the payment term?
100% T/T (large order, accept 30% T/T prepay 70% balance before shipping), Western Union, Paypal.