Is Zhejiang TMB Electric Co., Ltd. a manufacturer or a trading company?

We are a manufacturer with an integrated export team. Our production base in Liushi Town, Wenzhou covers about 5,700 m² with 92 staff, and the facility has been assessed on-site by TÜV Rheinland.

What is the minimum order quantity?

Most catalog models start from 5 pieces, and some timer switches from 1 piece, so buyers can test samples before volume orders. OEM branding and custom configurations are discussed per project.

Can an AC MCB be used on solar PV DC strings?

No. DC current has no natural zero-crossing, so the arc is harder to extinguish. Use a DC-rated MCB or MCCB whose rated DC voltage is at least the string open-circuit voltage at the lowest site temperature, and observe the marked polarity during wiring.

How do I choose the correct dual power automatic transfer switch?

Confirm the system type (2P for single phase, 3P or 4P for three phase; 4P also switches the neutral), the rated voltage (110/120 V or 220/230 V), the rated current of the load (63 A, 100 A or 125 A) and whether the application is grid-generator or grid-inverter backup.

Do you offer OEM and ODM services?

Yes. We support private label printing, custom packaging, current and voltage rating combinations, and custom PV combiner box configurations with breakers, fuses and SPD matched to your string design.

Which certifications and documents can you provide?

Listed models carry CE marking, the factory operates a certified quality management system and has a TÜV Rheinland on-site assessment report. Test reports, datasheets and declarations can be requested per model before ordering.

Over and Under Voltage Protector Manufacturers & Suppliers for Daejeon

Direct Engineering Solutions

Precision Voltage & Control Products for Daejeon Facilities

Engineered to deliver microsecond response times and continuous stability across research laboratories, Daedeok Innopolis pilot facilities, and commercial switchboards throughout Daejeon Metropolitan City.

CE Approved TOMZN 63A 80A Over Under Voltage Protector DIN Rail

TOMZN 63A/80A Adjustable Over & Under Voltage Protector

Dual Display Self-Recovery 110V-230V

Industrial 63A 3 Phase 3P+N DIN Rail Over Under Voltage Relay

63A 3-Phase 3P+N Over & Under Voltage Relay

Phase Sequence Voltage Asymmetry 380V/415V

Smart Control TOMZN Bluetooth Smart Timer Switch 85-265VAC

TOMZN Bluetooth Smart Timer Switch 85–265VAC 10A/30A

EasyCon App 28 Groups Loop Timing

Heavy Duty TOMZN TOS7-B Bluetooth Smart Timer Switch DIN Rail

TOMZN TOS7-B Bluetooth Smart Timer Switch 40A/63A

DIN Rail 35mm Remote App Countdown

Automated

TOMZN 1NO 1NC DIN Rail Weekly Programmable Timer Switch

TOMZN 1NO 1NC Weekly 7-Day Digital Time Switch

AC 220V/230V 12V-48V Multi 16A Relay

Versatile

TOS6-40 Bluetooth Time Control Switch 35mm DIN Rail

Wall / Rail 40A High Current AC85-265V

High Precision TOMZN New Type Single Phase Weekly Digital Timer Switch

TOMZN Advanced Digital 7-Day Programmable Timer

LCD Display Lithium Reserve 16A Micro-step

10-in-1 Modes TORT7 Series Delay ON Delay OFF 10in1 Asymmetric Cycler Time Relay

TORT7 Asymmetric Multi-Function Time Delay Relay

0.1s to 10 Days Pulse Generator Cycler Logic

Engineering Whitepaper & Market Analysis

Electrical Architecture, Grid Dynamics & Local Applications Across Daejeon

A technical guide on mitigating voltage fluctuation risks in South Korea’s central high-tech R&D corridor, optimizing equipment uptime, and complying with KEC (Korea Electrotechnical Code) standards.

Daedeok Innopolis Laboratory Environments

Daejeon hosts the pinnacle of Korean national research laboratories, including KAIST, KIMM, and ETRI. In high-frequency testing facilities, cleanrooms, and particle calibration chambers, small voltage drops or transient surges (voltage swells) can corrupt long-term data collection or destroy custom semiconductor silicon. Our self-resetting protectors disconnect under 0.1 seconds and reconnect only after steady sinusoidal equilibrium is confirmed.

Industrial Automation in Yuseong & Daedeok Complexes

From the Daedeok Techno Valley to the emerging International Science and Business Belt in Shindong/Dundong, automated robotic arms, programmable logic controllers (PLCs), and variable frequency drives (VFDs) run continuously. Under-voltage brownouts cause internal DC-link power capacitor stress and thermal overload in 3-phase induction motors. The 3P+N relays with asymmetric monitoring eliminate phase-loss burning risks instantly.

Commercial, Data Server & Clean Energy Hubs

The urban expansion of Dunsan and Yuseong modern smart complexes demands dynamic power distribution boards. Coupled with distributed rooftop solar in Chungcheongnam-do interconnecting with KEPCO’s regional 22.9kV-to-380V distribution grids, reverse-power feed and sudden grid decoupling cause severe transient overvoltages. Incorporating DIN-rail adjustable voltage guardians shields critical switchgear from erratic switching surges.

Device Model Series	Protective Trigger Parameters	Response Delay Range	Standard Daejeon Field Application
TOMZN 63A/80A Modular (1P+N)	Over: 230V–300V (Adj) / Under: 140V–210V (Adj)	Action: <0.1s \| Recovery: 1s–500s	Cleanroom server racks, medical testing devices, and smart apartment sub-panels.
TOMZN 3P+N Monitoring Relay	Phase asymmetry >13%, Over/Under 300V–460V AC	Tripping: 0.1s–10s \| Auto-Reset Delay	Heavy industrial CNC machines, clean air HVAC blowers in Daedeok Techno Valley.
Hybrid ATS + Voltage Protection	Dual Incomer Transfer with Under/Over Cutoff	Transfer time <50ms seamless logic	R&D uninterrupted power supplies (UPS backup) and hospital backup generator sets.
TORT7 / Bluetooth Time Control	Microcontroller timing combined with contactor trips	Precision stepping: 0.1s to 10 days	Autonomous environmental control chambers and sequential high-power laboratory loads.

Market Evolution & Grid Resilience

Localized Industry Trends: Smart Power Grids in Chungcheong Province

Analyzing the intersection between KEPCO modernization initiatives, South Korea's K-Taxonomy decarbonization mandates, and the surging need for distributed sub-circuit protection devices.

1. KEPCO Microgrid & Smart Substation Interconnection

With Daejeon designated as an epicenter for smart-grid pilot programs, the penetration of high-capacity ESS (Energy Storage Systems) and distributed photovoltaic arrays has introduced non-linear harmonics and rapid voltage rise incidents. Standard circuit breakers cannot identify harmonic voltage spikes; dedicated over-and-under voltage devices ensure equipment automatically isolates when inverter oscillations violate safety envelopes.

2. Strict Enforcement of Korea Electrotechnical Code (KEC)

Following revisions in national electrical engineering codes, engineers and panel manufacturers in Daejeon must prioritize surge mitigation and transient under-voltage tripping configurations for high-density occupancy facilities. Specifying DIN-rail units equipped with digital LED real-time voltage monitoring allows maintenance technicians to diagnose phase voltage drops before thermal breakdown occurs.

3. IoT-Integrated Preventive Maintenance

Traditional passive protection is migrating rapidly toward active digital surveillance. Systems incorporating Bluetooth and Wi-Fi smart controls allow research team supervisors and facility managers in Daedeok to log real-time power metrics, configure threshold limits over encrypted smartphone protocols, and implement remote lockouts without exposing technicians to live switchboard hazards.

Direct Manufacturing Authority

Why Daejeon EPCs, Panel Builders & Wholesalers Partner with TMB

Combining 24 years of manufacturing heritage in Liushi—the global capital of low-voltage electrical apparatus—with rigorous TÜV Rheinland certified production quality management.

TÜV Rheinland Verified

Our modern 5,700 m² factory footprint in Wenzhou undergoes extensive on-site audit verification by TÜV Rheinland, guaranteeing complete supply chain authenticity, workplace compliance, and process transparency.

Industrial Supply Chain

Situated in the heart of Liushi, our internal tooling, silver contact sintering, arc suppression fabrication, and flame-retardant VO grade casing molding operate with minimal lead-times and unbeatable economies of scale.

Flexible B2B Procurement

We eliminate barriers for pilot prototyping and localized testing: catalog models start with a minimum order quantity (MOQ) of just 5 units, backed by comprehensive OEM/ODM custom laser marking, label languages, and packaging.

Full Circuit Protection

We are a unified manufacturer spanning DC MCBs up to 1000V, high-current DC MCCBs, automatic transfer switches (ATS), PV combiner boxes, surge protection devices (SPDs), and smart energy meters.

Direct Buyer Clarifications

Frequently Asked Technical & Procurement Questions

Specific operational, compliance, and ordering details commonly evaluated by Korean engineers and supply-chain procurement teams.

Are your over and under voltage protectors suitable for the 220V 60Hz Korean electrical system?

Yes. All single-phase units operate flawlessly at 220V nominal voltage across both 50Hz and 60Hz utility grids. The adjustable over-voltage window (typically set between 240V–275V) and under-voltage threshold (typically set between 160V–200V) can be customized directly on the digital interface or programmed from the factory to match specific KEPCO line tolerance margins.

How does the self-recovery mechanism operate after a grid voltage fault occurs?

When grid voltage exceeds the trip threshold or drops into brownout range, the high-speed microprocessor triggers the magnetic latching relay or internal trip mechanism in under 0.1s. Once voltage returns within normal operating limits, a built-in countdown delay (adjustable from 1s to 500s) begins. This prevents destructive load cycling on refrigeration compressors, laboratory chillers, and HVAC equipment during intermittent grid oscillation.

Can we brand your voltage protectors with our private label or obtain KC certification support?

Yes. Zhejiang TMB Electric provides end-to-end OEM and ODM support. We provide silk-screen laser marking for private brand logos, customized carton packaging, Korean language instruction manuals, and provide technical parameter datasheets, schematics, and raw material declarations required for KC certification testing and import clearance.

What is the difference between an Over/Under Voltage Protector and a Surge Protective Device (SPD)?

This is a vital distinction in power engineering. A Surge Protective Device (SPD) protects against microsecond, kilo-volt transient spikes caused by lightning or high-voltage grid switching by shunting transient energy to earth via varistors (MOVs). An Over/Under Voltage Protector defends against sustained (millisecond to hours) root-mean-square (RMS) grid swells, sags, and lost neutral conditions by opening the line contactor and isolating the downstream circuit. Both devices are complementary and should be installed together in high-reliability switchboards.

What are your typical shipping lead times and freight options to Incheon or Busan for Daejeon delivery?

Standard sample orders and low-MOQ inventory models ship within 48 to 72 hours via air courier (FedEx, DHL, SF Express) with 2–4 days transit time to Daejeon. Volume OEM maritime shipments dispatch from Ningbo or Shanghai port directly to Busan or Incheon container ports in approximately 3 to 7 days sea freight, ensuring exceptional supply chain agility.