
Circuit Breaker
AC MCB 1P–4P 3–63 A, DC MCCB up to 1000 V DC for PV and battery main switching.
View rangeZhejiang TMB Electric Co., Ltd. designs and manufactures AC/DC miniature circuit breakers, DC molded case circuit breakers, PV combiner boxes, dual power automatic transfer switches, surge protective devices and smart protection relays for distributors, panel builders, EPC contractors and solar installers in more than 100 export markets.
One source for the complete DIN-rail line-up: from string-level DC protection in solar arrays to final-circuit AC breakers, backup power transfer and smart energy monitoring.

AC MCB 1P–4P 3–63 A, DC MCCB up to 1000 V DC for PV and battery main switching.
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IP65 pre-wired boxes with DC breaker, fuse and SPD; 1-in-1-out to multi-string designs.
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DIN-rail ATS 2P/3P/4P, 63/100/125 A, for grid-generator and grid-inverter backup.
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Adjustable thresholds, over-current limit and kWh display; 1-phase and 3P+N versions.
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DC SPD 500–1000 V, 10–20 kA / 20–40 kA, for PV arrays, inverters and battery systems.
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App-controlled breakers with kWh metering, timer and remote on/off for 110/220 V circuits.
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7-day programmable, Bluetooth and multi-function time relays for lighting, pumps and HVAC.
View rangeZhejiang TMB Electric Co., Ltd. has spent 24 years in the low-voltage electrical industry. Our factory in Huabei Village, Liushi Town, Wenzhou sits inside a supply chain where breaker mechanisms, silver contacts, arc chutes and flame-retardant housings are produced within a few kilometres — this is how we keep tooling cost, sample lead time and component traceability under control.
We focus on the devices that protect modern hybrid power systems: DC protection for solar strings and batteries, automatic transfer between grid and backup sources, and voltage and surge protection for sensitive loads. Products ship to distributors, wholesalers, panel builders and solar EPCs who need consistent quality across repeat orders.
Custom manufacturer with in-house assembly and testing for protection devices.
On-site factory assessment by TÜV Rheinland; QMS certified.
Private label printing, packaging, rating combinations and box layouts.
More than 10 years of export experience assessed by independent third parties.

Real workshop imagery from our Wenzhou facility. Every protection device passes through defined inspection checkpoints before packing.





Contacts, bimetals, copper busbars and housings sampled against drawings.
Mechanism and terminal torque controlled at fixed workstations.
Thermal and magnetic trip points verified against the rated curve.
Insulation and withstand voltage checked between poles and to frame.
ATS transfer, protector thresholds and timer programs tested at power.
Marking, packaging and carton labels audited before shipment.
Buyers rarely purchase a single component. These are the device combinations our customers most often order together for complete systems.

String combining and DC isolation between PV modules and the inverter: DC MCB or fuse per string, DC SPD on the output and an IP65 enclosure for outdoor mounting.

Final-circuit protection for homes and apartments with AC MCBs, AC SPD at the incomer and an adjustable voltage protector to guard appliances against grid swells and sags.

Automatic switching between grid and generator or inverter output keeps critical loads running. Pair the ATS with metering and timer control for load scheduling.

Remote on/off, kWh tracking and scheduling from a phone app — ideal for rental properties, water heaters, EV charging circuits and pumps.
Pre-assembled, pre-wired enclosures that reduce installer labour on site. Configure breakers, fuses and SPD per string count and system voltage.
| Model | Configuration | Key Data |
|---|---|---|
| HT 2-Way PV Box | 1 input / 1 output, DC breaker, matching wires | IP65 waterproof |
| 8-Way DC Box | 1 in / 1 out with breaker, fuse, SPD, dual terminals | 600 V DC, 16–63 A |
| HT Distribution Box | 5 / 8 / 12 / 15 / 18 ways, MCB enclosure | Outdoor waterproof |
| HT-9WAY ATS Box | Dual power ATS + 7-day timer, pre-wired | 2P 63 A, 220 V AC |
| Dual Power Box | ATS output with MCB overload/short-circuit protection | 2P 63 A |




High-volume protection devices for final circuits, PV strings and battery main switching. Our 1P AC MCB alone shipped close to 10,000 units in 180 days.
| Model | Type | Ratings |
|---|---|---|
| TOB1-63H | 1P AC MCB, C curve | 230/400 V~, 50/60 Hz, 3–63 A |
| 2P DC MCB | Solar mini breaker | 1000 V DC, 3–63 A |
| 2P DC MCB HC | High current, C curve | 600 V DC, 80 / 100 / 125 A |
| TOM7Z | 2P DC MCCB | 1000 V DC, PV overload protection |
| DC MCCB B | 2P DC MCCB, B curve | 500 V DC |




DIN-rail mounted, uninterrupted transfer between two sources. Available in 110/120 V and 220/230 V versions with single and three-phase pole options.
| Model | Poles / System | Ratings |
|---|---|---|
| ATS 2P 230 V | 2P, single phase | 220/230 V, 63 / 100 / 125 A |
| ATS 2P 120 V | 2P, single phase | 110/120 V, 63 / 100 / 125 A |
| ATS PV/Inverter | 2P, grid + inverter | 63 / 100 / 125 A |
| ATS 3P / 4P | Three phase (4P switches N) | 63 / 100 / 125 A |
| TOQ3 | 2P / 4P MCB type, indicator light | 63 / 125 A, 50/60 Hz |




Supporting devices that complete a distribution board and frequently appear on the same purchase order.








Certificates, test reports and the third-party factory assessment are available for review. Ask for the documents of the exact model you plan to import.
On-site verification of facility, staff and production capability.
Breakers, ATS, PV boxes and protectors for EU-market compliance.
Quality management system certification with inspected materials.
Datasheets, test reports and declarations supplied per model.
Most returns and field failures in low-voltage protection come from mismatched ratings, not defective parts. Confirm these parameters before sending your requirement.
| Application | Recommended Device | Parameters to Confirm | Common Mistake to Avoid |
|---|---|---|---|
| PV string protection | 2P DC MCB or PV fuse in combiner box | Rated DC voltage ≥ string Voc at the coldest site temperature; current ≈ 1.25 × Isc or per module fuse rating | Using AC MCBs on DC — DC arcs have no zero-crossing and may not extinguish |
| Battery / inverter DC main | 2P DC MCB 80–125 A or DC MCCB | Battery bank voltage, continuous current, breaking capacity, polarity marking | Reversing polarity on polarized DC breakers during wiring |
| Grid / generator backup | Dual power ATS 2P / 3P / 4P | Phase system, nominal voltage 120 V or 230 V, load current, whether neutral must be switched | Choosing 3P where the generator neutral must be isolated (use 4P) |
| Unstable grid voltage | Over & under voltage protector | Adjustable trip window, reconnection delay, rated current 40/63/80 A | Setting recovery delay too short for compressor loads |
| Lightning & switching surges | AC SPD at incomer, DC SPD at PV input | Uc (max. continuous voltage), In / Imax, protection level Up vs. equipment withstand | Installing SPD without back-up overcurrent protection |
| Scheduled loads | Digital / Bluetooth timer switch + contactor | Supply voltage, contact rating, number of programs; use a contactor for inductive or high loads | Switching motors directly through a 16 A timer contact |
This guide is general engineering information. Final selection must follow local wiring regulations and the device datasheet. Our engineers can review your single-line diagram.
Share your single-line diagram, ratings and target market — our team replies with matched models and documents.
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