Complete Electrical Equipment Supplier
Zhejiang Shidian Electrical
SAD
Delivering box-type substations, HV/LV switchgear and distribution boards for industrial, municipal and renewable energy applications.
Core Products
Core Products
A complete product range from transformation and distribution to control — engineered for every project requirement.
Full Lifecycle Support
Our Services
From needs analysis to on-site delivery — comprehensive electrical services covering every stage of your project.
Equipment Rental
Short and long-term rental of box-type substations, HV/LV switchgear and more — reduce upfront investment and handle temporary power requirements with flexibility.
Fast Quotation
Submit drawings or equipment lists and receive a professional, accurate quote for complete electrical packages. Quick turnaround to support your procurement decisions.
System Design
Based on site conditions and load requirements, we provide complete electrical system design drawings and equipment selection recommendations to ensure safety and compliance.
Installation & Commissioning
Our professional engineering team handles on-site installation and commissioning, delivering full commissioning reports and operator training to ensure smooth start-up.
After-sales Service
Free warranty repairs and cost-effective post-warranty maintenance with ample spare parts inventory and rapid response to keep your equipment running reliably long-term.
Featured Projects
Engineering Cases
Rooted in Zhejiang, serving clients nationwide — trusted for quality delivery.
Complete Electrical System for Energy Storage Plant
Complete switchgear and protection-control systems for a large storage project, supporting grid peak-shaving and frequency regulation.
HV/LV System for Photovoltaic Power Plant
Step-up transformers, grid-connection panels and metering equipment complying with grid-connection technical standards.
Box-type Substation for Large Industrial Park
Stable power supply across multiple factory buildings with a pre-assembled substation solution, cutting construction time by 40%.
Dual-Feed Power System for Hospital Data Centre
Dual-incomer and bus-coupler switching scheme ensures uninterrupted power for critical hospital systems.
Municipal Road Lighting & Distribution Project
LV distribution boards and substations for municipal arterial roads, meeting city lighting and road power planning requirements.
Distribution System Upgrade for Shopping Complex
Full upgrade of aging distribution infrastructure with smart monitoring modules, reducing fault response time to minutes.
Quality Assurance
Certifications
Backed by internationally recognised certifications and type test reports — ensuring every product meets the highest safety and compliance standards.
ISO 9001:2015 Quality Management System
- Certificate No.
- CNCA-R-2024-XXXXX
- Issuing Body
- China Quality Certification Centre (CQC)
- Applicable Scope
- R&D, manufacturing and sales of complete electrical equipment
Box-type Substation Type Test Report
- Certificate No.
- TEST-YBM-2023-XXXX
- Issuing Body
- National Electrical Equipment Quality Inspection Institute
- Applicable Scope
- YBM-series American & European box substations
HV Switchgear Type Test Report
- Certificate No.
- TEST-KYN-2023-XXXX
- Issuing Body
- National HV Apparatus Quality Inspection Centre
- Applicable Scope
- KYN28A-12 armoured withdrawable switchgear
LV Distribution Panel Type Test Report
- Certificate No.
- TEST-GGD-2023-XXXX
- Issuing Body
- National LV Apparatus Quality Inspection Centre
- Applicable Scope
- GGD-series fixed low-voltage switchgear
China Compulsory Certification (CCC)
- Certificate No.
- CCC-2023-XXXXXXXX
- Issuing Body
- China Quality Certification Centre (CQC)
- Applicable Scope
- Circuit breakers, RCDs and other LV apparatus
State Grid Qualified Supplier
- Certificate No.
- SG-SUP-XXXX-XXXX
- Issuing Body
- State Grid Corporation of China
- Applicable Scope
- Transmission & distribution equipment and materials
Industry Knowledge
Technical Insights
Professional knowledge in complete electrical equipment — helping engineers make informed decisions.
Factory Power Distribution Energy Retrofit: Planning, Execution and ROI
A practical guide to upgrading ageing factory distribution systems with a sample ROI calculation.
HV/LV Switchgear Technical Overview: Types, Standards and Selection
A practical guide to the main HV/LV switchgear types covering structure, applicable standards and engineering selection criteria.
Box-type Substation Selection Guide: Parameters and Use Cases
A systematic overview of key technical parameters and typical application scenarios for box-type substations.
Frequently Asked Questions
FAQ
Answers to common questions about product selection, pricing, delivery and after-sales service.
What is the difference between a box-type substation and a conventional transformer?
A box-type substation integrates HV switchgear, transformer, and LV distribution equipment into a single prefabricated enclosure. Compared to traditional civil-construction substations, it offers a smaller footprint, faster installation, and no civil works. A conventional transformer only performs voltage conversion and requires additional equipment to form a complete power distribution system.
How can I get a quotation?
You can request a quotation by: 1) emailing us your load data, application scenario and technical requirements; 2) submitting an enquiry via the contact page on our website; 3) calling our sales team directly. We typically respond with a formal quotation within 1–2 business days.
What is the warranty period?
Our standard warranty is 12 months from the date of acceptance. Quality-related failures within the warranty period are repaired or replaced free of charge. Post-warranty repair services and long-term spare-parts supply are also available.
How do I select the correct transformer capacity?
Calculate the actual load based on total installed power × demand factor (0.7–0.85) × power factor (0.85–0.95), then add a 15–20% reserve margin. Contact our engineers with your load data for a professional recommendation.
Latest Updates
Announcements
New Year 2025 Holiday Notice
New Year 2025 Holiday NoticeOur office will be closed on January 1st. For urgent matters, please contact our on-call number.
ISO 9001 Annual Quality System Audit Passed
ISO 9001 Annual Quality System Audit PassedZero non-conformances reported; the quality management system continues to operate effectively.
2025 Product Selection Handbook Released
2025 Product Selection Handbook ReleasedComprehensive specifications for box-type substations and HV/LV switchgear are now available for download.
About Us
About Us
SAD (Zhejiang Shidian Complete Electrical Equipment Co., Ltd.) is a professional manufacturer and supplier of complete electrical equipment headquartered in Zhejiang, China. Quality-driven and customer-focused, we serve industries including manufacturing, urban infrastructure and renewable energy. Website: 21b.cn
5 Categories
Product Range
Full Lifecycle
Professional Service
Strict Standards
Quality Control
Contact Us
Contact Us
For product inquiries, quotations or technical support, please reach us through the channels below.
Brand Partnerships
Partner Brands
Deep collaboration with leading global and domestic electrical brands to ensure component quality and traceability.