Control Relay
TORT7 Series Delay-ON Delay-OFF 10in1 Asymmetric Cycler Time Relay Multi-function Timer Switch
0.1S-10D Interval • Pulse Generator • Modular Rail Mount
Industrial-Grade DC Isolation Engineering for the PJM Interconnection Corridor
As the Greater Philadelphia metropolitan area—spanning Montgomery, Bucks, Chester, Delaware, and Philadelphia counties—accelerates commercial, industrial, and community solar integration under the Pennsylvania Alternative Energy Portfolio Standards (AEPS), DC balance-of-system (BOS) safety has moved to center stage. Zhejiang TMB Electric Co., Ltd. delivers direct factory-engineered DC isolator switches, high-voltage PV disconnects, and pre-integrated combiner solutions engineered to withstand demanding operational conditions while conforming to rigorous NEC 690 and UL 98B performance standards.
Factory Inventory Direct
Curated DC Isolation, Switching & Array Protection Components
Engineered at our Liushi production facility and shipped directly to electrical distributors, solar installers, and panel builders serving Pennsylvania, New Jersey, and Delaware.
Wireless Timing
TOS6-40 Bluetooth Time Control Switch 35mm DIN Rail Wall-mounted AC85-265V 40A
Bluetooth Control • Loop Timing • Countdown Integration
Smart Switch
TOMZN TOS7-B Bluetooth Smart Timer Switch 40A 63A 85-265V EasyCon App
28 Groups Timing • EasyCon App • DIN Rail 40A/63A Rated
BOS Management
TOMZN Bluetooth Smart Timer Switch 85-265VAC 10A 30A EasyCon Wall-mounted
Wall-Mounted • 10A-30A High Load • Cycle Timing Logic
System Relay
TOMZN New Type Din Rail Single Phase Weekly 7 Days Programmable Digital TIME SWITCH 16A
12V/24V/48V/230V Versatile • Weekly Cycle • LCD Display
Auxiliary Isolator
TOMZN 1NO 1NC Din Rail Single Phase Weekly 7 Days Programmable Relay AC 220V 16A
1NO + 1NC Dual Output • 35mm DIN Mount • Clean Contact
DC Breaker / Disconnect
2P DC MCB 1000V Solar Photovoltaic Mini Circuit Breaker & Disconnector 3–63A
1000V DC • Arc Chute Suppression • Non-Polarized Options
Combiner & Isolation
IP65 Solar Photovoltaic Pre-Wired Combiner Box with Integrated DC Isolator Switch
Weatherproof NEMA 4X Equiv. • Pre-Wired Breaker & SPD • 1-In-1-Out
24+
Years Engineering Heritage
5,700m²
TÜV Assessed Production Area
1000V+
Continuous DC Arc Extinction
5 PCS
Low Trial Batch MOQ
Application Scenarios
DC Disconnection & Isolation Use Cases in Southeastern Pennsylvania
From brownfield revitalizations in the Philadelphia Navy Yard to distribution logistics hubs along the I-95 corridor, DC isolator switches serve as the critical line of defense for personnel and capital equipment.
Commercial Rooftop PV Arrays
Distribution centers and cold storage facilities in Bucks and Montgomery counties require string isolators capable of interrupting up to 1000V DC under continuous load. Our isolators ensure rapid disconnect point compliance adjacent to string inverters, enabling safe preventative inspections without backfeed hazards.
Battery Energy Storage (BESS)
Philadelphia’s peaking power mitigation systems rely on 48V to 600V DC lithium-ion battery banks. TMB's high-current DC isolators and molded-case isolation switches provide heavy-duty bi-directional fault current isolation between the central storage rack and bidirectional hybrid inverters.
Rapid Shutdown Disconnectors
In accordance with Philadelphia Department of Licenses and Inspections (L&I) rooftop fire safety mandates, our external rotary DC isolator enclosures give municipal first responders a guaranteed, visible break point to de-energize rooftop module conductors to below 30V within 30 seconds.
Regional Trends: The PJM Clean Energy Transformation
The Mid-Atlantic grid, coordinated by PJM Interconnection headquartered in Valley Forge, PA, is undergoing unprecedented electrification. The surge in urban data centers across the regional corridor and ambitious emissions targets set by the City of Philadelphia have created extreme demand for robust DC equipment.
Field installations in Pennsylvania endure humid continental summers peaking past 95°F and freezing winter cycles down to single digits. Unlike alternating current, direct current has no natural zero-crossing point. Disconnecting a live 1000V DC string creates an intense sustained plasma arc. Zhejiang TMB Electric's DC isolators incorporate advanced permanent-magnet blow-out chutes and silver-alloy quick-make/quick-break mechanics that reliably snuff arcs in under 3 milliseconds, avoiding catastrophic thermal runaway.
Technical Specification Guide
Engineering Selection Matrix for Direct Current Disconnects
Select exact electrical ratings based on ambient operational temperature and string open-circuit calculations (Voc).
| Series Architecture | Rated Voltage (Ue) | Operational Amperage (Ie) | Arc Extinction Tech | NEMA / IP Enclosure | Standard Certifications |
|---|---|---|---|---|---|
| TMB-DS Rotary Isolator | Up to 1200V DC | 16A, 25A, 32A, 50A | Multi-Chamber Magnetic Arc Runners | IP66 Polycarbonate (UV-Stabilized) | CE Marked / IEC 60947-3 / UL 98B compliant logic |
| TMB-PV Combiner Disconnect | 600V / 1000V DC | 32A to 125A | Parallel Blade Quick-Break Contact | IP65 Enclosure / Wall-Mounted | TÜV Rheinland Assessed / ISO9001 QMS |
| TOM7Z Molded Case DC (MCCB) | 500V to 1000V DC | 100A, 160A, 225A, 250A | Heavy-Duty De-ionizing Grid | Panelboard / Distribution Base | CE / Third-Party Verified Laboratory Reports |
| TOS Modular DIN Disconnector | 500V / 1000V DC | 3A to 63A | Spring-Assisted Over-Center Mechanism | Modular DIN-Rail 35mm | RoHS / CE Mark |
Manufacturing Excellence
Direct-from-Source Reliability: Zhejiang TMB Electric Co., Ltd.
Situated in Huabei Village, Liushi Town, Wenzhou—the globally recognized epicenter of low-voltage electrical apparatus—Zhejiang TMB Electric Co., Ltd. leverages 24 continuous years of precision manufacturing experience. Our integrated facility spans 5,700 square meters of verified production floor space supported by 92 skilled technicians.
Because we operate inside China's most dense electrical supply cluster, our raw-material cycle—from oxygen-free copper busbars and electrolytic silver contacts to engineering-grade PA66 flame-retardant thermoplastics—is closely monitored with zero intermediate markup. Audited and verified on-site by TÜV Rheinland, our facility manufactures over US$ 3.3 million in exported electrical safety devices each year for panel builders and distributors in more than 100 countries.
Procurement & Engineering FAQ
Frequently Asked Questions by Mid-Atlantic Solar Engineers & Buyers
Practical technical answers to common integration, compliance, and shipping questions for the Philadelphia marketplace.
Why is an AC circuit breaker or disconnector unacceptable for DC solar isolation in Pennsylvania?
Alternating current passes through a natural zero-voltage point 120 times every second (at 60Hz), naturally allowing contacts to extinguish arcs. Direct current (DC) has no natural zero-point; when contacts separate under voltage (e.g., an 800V DC string in a Bucks County commercial system), a continuous, intense electrical plasma arc bridges the gap. Installing an AC breaker on DC strings causes contact welding, severe enclosure burn-through, and critical fire hazards. Dedicated DC isolators utilize specialized magnetic blow-out coils and oversized arc de-ionizing fins to stretch and eliminate the arc within milliseconds.
How do outdoor temperature extremes in Philadelphia impact DC isolator voltage calculations?
Solar PV panels exhibit an inverse temperature coefficient: lower temperatures produce higher open-circuit voltage (Voc). Winter conditions in Southeastern Pennsylvania frequently reach 0°F to 14°F (-18°C to -10°C). Designers must compute string Voc adjusted for the local record low temperature according to NEC 690.7. If an unadjusted string reads 880V at 25°C, it can easily exceed 1000V in freezing Philadelphia conditions. Your DC isolator must therefore be rated for 1000V or 1200V continuous DC to avoid catastrophic insulation breakdown.
What is the factory lead time and logistics route for deliveries to Philadelphia?
Standard catalog products are ready for dispatch from our Wenzhou facility with a low minimum order quantity starting from just 5 pieces. For containerized or volume pallet orders, ocean freight ships through Ningbo or Shanghai port with arrival at the Port of Philadelphia (Packer Avenue Marine Terminal) or Port of NY/NJ, typically spanning 25 to 32 days transit. Expedited air shipments for sample evaluations and urgent construction phase deadlines arrive at Philadelphia International Airport (PHL) via express courier within 5 to 7 business days.
Does Zhejiang TMB Electric provide customized OEM/ODM branding and private labeling?
Yes. We routinely support regional US electrical wholesalers, BOS system aggregators, and private brands. We provide silk-screened laser customer logos, bespoke enclosure knockout patterns, custom terminal screw torques, and pre-wired combiner assemblies pairing DC isolators, PV surge protective devices (SPDs), and DC fuse blocks tailored to individual engineering schematics.
What documentation and third-party certifications accompany our shipments?
Every product batch is supported by comprehensive documentation: CE certificates of conformity, full factory routine testing reports (dielectric withstand, insulation resistance, contact resistance), RoHS compliance declarations, and TÜV Rheinland facility assessment verification credentials. Complete engineering submittal packets including step-file dimensional drawings and wiring schematics are provided before production confirmation.
Ready to Streamline Your Solar DC Protection Supply Chain?
Connect directly with our senior application engineering desk. Submit your single-line electrical diagram (SLD), array specifications, or tender requirements for competitive factory-direct pricing within 24 hours.