Manufacturing
- Based in Liushi, Wenzhou, with direct access to the region's component supply chain
- Moulding, assembly and calibration under one roof
- Rated current, poles and curves configured to order
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Low-Voltage Circuit Protection Manufacturer
MCB, MCCB, ACB & Surge Protection Devices Built for Global Distribution
Zhejiang Graybar Electric Co., Ltd. designs and produces circuit breakers, surge protective devices, automatic transfer switches and AC contactors in Liushi Town, Wenzhou — China's largest cluster for low-voltage electrical components. We supply importers, wholesalers, panel builders and EPC contractors who need consistent quality, clear documentation and flexible order sizes.
OEM / ODM Manufacturer & Exporter On-site Verified Supplier IEC-Referenced Design
6Core product families from 63A MCBs to intelligent ACBs
5 pcsStarting MOQ for standard MCB, MCCB & SPD models
1 pcStarting MOQ for air circuit breakers — sample before you scale
4.5/5Average buyer rating on our verified storefront
Product Category
Complete Low-Voltage Protection Portfolio
Source final-circuit, feeder and incomer protection from one factory — one quality system, one set of documents and consolidated shipping for your distribution boards and switchgear projects.
Miniature Circuit Breaker
DIN-rail MCBs, 1P–4P, up to 63A for residential and commercial boards.
View rangeMoulded Case Circuit Breaker
MCCB frames 125A–250A, 1P–4P, for feeders and motor circuits.
View rangeAir Circuit Breaker
Intelligent universal ACBs in draw-out and fixed versions for main incomers.
View rangeSurge Protective Device
Single and 3 phase SPDs to protect equipment from lightning and switching surges.
View rangeAutomatic Transfer Switch
Dual power ATS for seamless switching between grid and generator supply.
View rangeAC Contactor
Electromagnetic contactors for motor control, HVAC and lighting circuits.
View range
Why Buyers Choose Graybar
Our Advantages
Four capabilities that reduce sourcing risk for distributors and project buyers.
Quality Inspection
- Incoming inspection of contacts, bimetals and housings
- Trip-time and dielectric checks before packing
- Batch traceability for every shipment
Delivery
- Low MOQs for trial orders, scalable to full containers
- Export cartons with shock-proof inner packing
- Mixed-category consolidation in one shipment
Service
- OEM private label, packaging and multilingual manuals
- Engineering support for selection and coordination
- Responsive after-sales handled by email
Factory Strength
About Zhejiang Graybar Electric
Zhejiang Graybar Electric Co., Ltd. is a manufacturer and trading company specialising in low-voltage protection and switching devices. Our main lines — MCB, MCCB, ATS and SPD — are complemented by air circuit breakers and AC contactors so buyers can complete a distribution panel bill of materials from a single source.
Being located in Liushi Town gives us practical advantages that matter to importers: short lead times on raw materials such as silver-alloy contacts and flame-retardant housings, experienced assembly technicians, and dense logistics links to Ningbo and Shanghai ports.
- Address: Huangyu Village, Liushi Town, Wenzhou, Zhejiang, China
- Business type: Manufacturer & trading company (authenticated)
- Verification: Premises checked on-site by a third-party verification process
- Buyers served: Wholesalers, panel builders, contractors and private-label brands
Certificate & Compliance
Engineered to International Standards
Each product family is designed with reference to the relevant IEC standard, so your compliance team knows exactly which test regime applies before placing an order.
IEC 60898-1
Miniature circuit breakers for household and similar installations
IEC 60947-2
Moulded case and air circuit breakers for industrial use
IEC 61643-11
Surge protective devices connected to low-voltage power systems
IEC 60947-6-1
Transfer switching equipment for dual power systems
IEC 60947-4-1
Contactors and motor starters for electromechanical control
Available certificate copies and type-test reports are provided per model on request — email [email protected] with the part numbers you are evaluating.
Transparency
Verify Our Track Record Independently
Do not just take our word for it. Review third-party data on our trading history, buyer feedback and credit standing before you commit.
Credit Profile
Business registration and credit information.
Transaction Level
Verified online transaction performance.
Trade History
Past shipments and destination markets.
Ratings & Reviews
Feedback written by real buyers.
Trade Capacity
Export markets, terms and logistics capability.
Video Introduction
Walk through our workshop and lines.
Series 01 · Final Circuit Protection
Miniature Circuit Breakers (MCB)
Compact DIN-rail breakers that protect cables and loads against overload and short circuit in residential, commercial and light-industrial distribution boards. Available in single to four pole configurations with ratings up to 63A at 230/400V AC.
Read More
63A 400V Miniature Circuit Breaker
- Rated currentUp to 63A
- Rated voltage400V AC
- Mounting35 mm DIN rail
- MOQ5 pieces
1P / 2P / 3P / 4P DIN Rail MCB
- Poles1P, 2P, 3P, 4P
- ApplicationDistribution boards
- ProtectionOverload & short circuit
- MOQ5 pieces
Series 02 · Feeder & Motor Protection
Moulded Case Circuit Breakers (MCCB)
Robust MCCBs for sub-distribution feeders, motor control centres and machine panels. Our 125A–250A frames are offered from 1P to 4P; 4-pole versions switch the neutral for TN-S and TT systems with unbalanced or harmonic loads.
Read More
Series 03 · Main Incomer Protection
Air Circuit Breakers (ACB)
Intelligent universal circuit breakers for main switchboards, transformer secondaries and generator incomers. Choose draw-out construction for maintenance without busbar shutdown, or fixed type for compact, cost-efficient panels.
Read More
Draw-Out Type Air Circuit Breaker
- InstallationDraw-out cradle
- TypeUniversal ACB
- Best forCritical incomers
- MOQ1 piece
Intelligent Universal Circuit Breaker, Fixed Type
- InstallationFixed, bolted
- ControllerIntelligent trip unit
- Best forCompact switchboards
- MOQ1 piece
Series 04 · Overvoltage Protection
Surge Protective Devices (SPD)
DIN-rail surge arresters that divert lightning-induced and switching transients to earth, protecting inverters, drives, controls and household electronics. Single phase and 3 phase variants cover residential boards through to industrial distribution.
Read More
Single Phase AC Surge Protector
- SystemSingle phase, 230V
- UseResidential & commercial
- MOQ5 pieces
Series 05 & 06 · Switching & Control
Transfer Switches & AC Contactors
Automatic Transfer Switch
Dual power ATS for hospitals, data rooms, telecom sites and commercial buildings with standby generators.
- FunctionGrid ↔ generator changeover
- Design referenceIEC 60947-6-1
- Typical useCritical & standby loads
AC Contactor
Electromagnetic contactors for starting motors, pumps, compressors, heaters and lighting groups.
Buyer's Selection Guide
Which Protection Device Fits Your Project?
A quick engineering reference our sales engineers use when reviewing buyer specifications. Use it to shortlist the right family before requesting datasheets.
| Device | Position in the system | Our listed range | Design reference | Selection tip |
|---|---|---|---|---|
| MCB | Final circuits: sockets, lighting, small loads | 1P–4P, up to 63A, 230/400V | IEC 60898-1 | Pick the trip curve by load: B for resistive, C for general/motor, D for high inrush. |
| MCCB | Sub-distribution feeders, MCCs, machine panels | 1P–4P, 125A–250A frames | IEC 60947-2 | Check breaking capacity (Icu/Ics) against prospective fault current at the panel. |
| ACB | Main incomers, transformer & generator breakers | Draw-out and fixed, intelligent controller | IEC 60947-2 | Choose draw-out where downtime is costly; fixed where space and budget are tight. |
| SPD | Service entrance and sub-boards | Single phase and 3 phase | IEC 61643-11 | Match pole configuration to the earthing system (TN-C, TN-S, TT) and install with short leads. |
| ATS | Between utility, generator and critical loads | Dual power transfer switches | IEC 60947-6-1 | Size by load current and confirm controller logic (auto-return, delay settings). |
| AC Contactor | Motor starters, HVAC, lighting control | AC electromagnetic contactors | IEC 60947-4-1 | Select by utilisation category (AC-1 / AC-3) and coil voltage, not only current. |
Final selection should always be confirmed by a qualified electrical engineer against local wiring regulations. Send your single-line diagram to [email protected] for a free technical review.
Working With Us
From Specification to Shipment
Share Requirements
Email ratings, quantities, target market and any branding needs.
Technical Confirmation
Our engineers confirm models, standards and documentation.
Sample Approval
Low MOQs let you test fit, function and labelling first.
Production & QC
Batch production with trip and dielectric checks before packing.
Export Delivery
Export packing, documents and consolidated shipping to your port.
FAQ
Questions Buyers Ask Us Most
What is the minimum order quantity for your circuit breakers?
Standard MCB, MCCB and SPD models start from 5 pieces per model, and air circuit breakers start from 1 piece, so buyers can test samples before scaling up to container orders.
Do you offer OEM and ODM services?
Yes. We support private labelling, laser-marked logos, customised ratings, packaging and multilingual manuals. Send your drawings or specification sheet to [email protected] for a technical review.
Which standards are your products designed to?
Products are designed with reference to IEC standards: IEC 60898-1 for MCBs, IEC 60947-2 for MCCBs and ACBs, IEC 61643-11 for surge protective devices, IEC 60947-6-1 for transfer switching equipment and IEC 60947-4-1 for contactors. Available certificates and test reports can be requested per model.
What is the difference between a draw-out and a fixed type air circuit breaker?
A draw-out ACB sits in a cradle and can be racked out for inspection or replacement without disconnecting busbars, reducing downtime in critical switchboards. A fixed type ACB is bolted directly to the busbars, which is more compact and economical where maintenance windows are acceptable.
Should I choose a single phase or 3 phase surge protection device?
Match the SPD to the supply system: single phase (1P+N) units protect residential and light commercial 230V boards, while 3 phase (3P or 3P+N) units protect 400V distribution and industrial panels. Earthing system (TN-C, TN-S, TT) also determines the pole configuration.
Planning a Distribution Board or Switchgear Order?
Send your BOM or single-line diagram to [email protected] — an engineer, not a bot, will reply.