Wengart Digital Timer Switch for Off-Grid DIYers & Caravan Sparkies, 230V Mains Blowouts & Voltmeter Guesswork Faff, Low-Voltage AC/DC 12V 16A 7-Day Clock with Volt-Free Contacts (THC15A)

• 12V Low-Voltage Input: Precision-calibrated strictly for AC/DC 12V low-voltage auxiliary power networks. Eliminates dangerous 230V mains voltage mismatch blunders, component blowouts, and layout faff inside campervan conversions, narrowboats, and battery arrays.
• Volt-Free Topography: Engineered with an isolated potential-free (volt-free) 1NO/1NC changeover relay across terminals 3-4-5. Safely breaks or bridges completely independent circuit loops without carrying unauthorized live back-feed currents.
• Granular Chrono Settings: Automating schedules for 12V LED lighting strips, hydroponic grow setups, or DC livestock ventilation fans. Supports up to 28 customizable on/off weekly program groups down to 1-minute increments to end scheduling faff.
• High-Capacity Shunting: Upgrading remote sub-panels to drive standalone loads smoothly without continuous maintenance shifts. Reliably switches a robust 16A resistive load at 250VAC/DC without contact fusion or localized terminal chattering.
• Blackout Power Backing: Running critical automation loops in isolated outdoor buildings or mobile vehicles prone to primary battery isolation. Features an internal 1.2V/40mA rechargeable cell providing over 60 days of program preservation.

The Low-Voltage AC/DC 12V Power Firewall for Flexible 7-Day Off-Grid Hardware Automation Zoning out automated timing matrices across modern British off-grid systems—whether you are organizing campervan electrical conversions, managing narrowboat auxiliary loops, or structuring independent solar-powered agricultural irrigation grids—demands a resilient and flexible switch foundation. The Wengart THC15A Low-Voltage Programmable Timer Switch is a trade-grade modular clock controller engineered to act as an absolute system firewall. Operating safely inside a standard 36mm wide shell, this 12V device provides independent power scheduling to isolate delicate electronic logic from main grid fluctuations, maintaining continuous vehicle and property uptime. Advanced Volt-Free 1NO/1NC Contact Topology Eliminating Control Loop Interference We understand that a primary frustration for electrical contractors ("Sparkies") when deploying generic digital rail timers is the rigid layout that automatically cross-links internal chassis power input directly to the switched output terminals. Wengart addresses this serious field bottleneck by utilizing a professional, completely isolated Volt-Free (Potential-Free) contact relay across ports 3, 4, and 5. This changeover layout allows maintenance technicians to switch completely separate voltage lines, external control signals, or isolated DC circuits safely without the faff of adding auxiliary slave relays. Technical Specifications: - Core Functional Framework: 7-Day Digital Weekly Programmable Electronic Time Clock - Structural Output Contact Form: Potential-Free / Volt-Free Changeover Relay Topology (1NO / 1NC Optional) - Operating Chassis Power Input: AC / DC 12V Low Voltage Micro-Grid Matrix Only - Maximum Switching Load Capacity: 16A at 250VAC Resistive (Inductive Motor Load: 8A Rating) - Programmable Memory Slots: Fully Customizable Scheduling Configurations up to 28 Independent Groups On/Off - Internal Clock Data Memory Reserve: High-End 1.2V/40mA Ni-MH Cell rated for ≥ 60 Days Power Preservation - Minimum Operational Setup Interval: Precision Control Down to 1 Minute (Range: 1min ~ 168 hours) - Physical Form Factor Sizing Profile: Slim 86.5mm x 36mm x 65.5mm Footprint (Fits standard 35mm DIN Rails) Frequently Asked Questions & Rufus Expert Guidance Q: Can I connect my standard UK 230V mains power line directly into the 1 and 2 terminal power feed of this device? A: Absolutely not. Doing so will violently blow out the internal micro-transformer and destroy the unit instantly. Terminal 1 and 2 are engineered strictly and exclusively to operate under a low-voltage **AC/DC 12V power envelope** (such as leisure batteries, camper solar banks, or step-down transformers). If you are working within a 230V household grid, you must specify our 230V model variant. Always double-check your incoming feed voltage with a multimeter before energizing to completely avoid dangerous installation faff. Q: Does the output terminal block automatically supply 12V power when the internal timer clicks ON? A: No, it does not. This is a critical engineering feature that catches out non-professional DIYers. Terminals 3, 4, and 5 operate as a completely isolated **Volt-Free (dry contact) changeover relay**. They function exactly like a light switch on the wall—they simply link or break the wire loop. If you want the timer to output 12V to your load, you must run a short physical bridge wire from your incoming Positive/Live feed into terminal 3 (Common). This allows the 12V current to pass out through terminal 4 the exact second your programmed ON schedule triggers. Q: How does the built-in backup battery function if the campervan's main leisure battery is isolated for winter storage? A: Wengart integrates a premium, industrial-grade 1.2V/40mA rechargeable Ni-MH battery core right inside the timer casing. While your vehicle is running or connected to solar power, this internal cell continuously tops itself up. If you isolate your main vehicle battery bank for seasonal winter storage, this internal backup cell keeps the microchip quartz and liquid crystal display (LCD) fully energized for up to 60 days. All your 28 weekly programmable groups stay locked in memory, avoiding tedious reprogramming faff when spring arrives.