i-PRO MC-TM400K2DMC PTC Protected Output Module
The i-PRO MC-TM400K2DMC is a PTC (Positive Temperature Coefficient) protected output module engineered to shield downstream relay circuits and control outputs in surveillance and access control installations. This inline protection device addresses a critical deployment challenge: electrical surges, wiring faults, and short-circuit events that disable integrated security systems or damage control boards. In field installations with long cable runs, unreliable power conditioning, or high-inductive loads (door strikes, gate motors, alarm strobes), the MC-TM400K2DMC operates passively — no configuration, no firmware updates — to prevent cascading failures that would otherwise take down an entire access-control or alarm integration.
Key Features
- PTC Protection Technology: Positive Temperature Coefficient element automatically limits current surge to safe levels. Self-resetting operation — no manual fuse replacement after fault events.
- Inline Installation: Connects between recorder/control board output terminals and the load (solenoid, relay, strobe, gate controller). No modification to existing wiring or control logic required.
- Multi-Load Compatibility: Rated for 12 VDC and 24 VDC control circuits powering door locks, access gates, alarm strobes, and auxiliary relay circuits common in commercial security deployments.
- Automatic Fault Recovery: Self-resetting PTC element restores normal operation once the fault condition clears — eliminates service truck visits for blown fuses on nuisance surges.
- Compact Form Factor: DIN-rail or panel-mount installation in control cabinets; minimal footprint allows integration into existing enclosures without major rewiring.
- Passive Design: No active components, no power draw from the protected circuit itself. Operates independently regardless of recorder firmware version or VMS platform.
PTC protection is especially valuable in outdoor or industrial environments where lightning-induced surges, AC induction on long cable runs, and poorly grounded auxiliary circuits create recurring short-circuit risk. A single MC-TM400K2DMC protecting a door-strike circuit or gate controller can prevent repeat damage claims and reduce unplanned downtime. In integrated installations spanning multiple buildings or long cable runs (>100 feet), protecting the most critical relay outputs with inline modules shifts maintenance burden from reactive (replacing burned boards) to preventive (one-time module cost).
Integration with i-PRO recorders and control systems requires no additional configuration — the module operates entirely at the hardware level. Verify compatibility with your specific recorder model (check i-PRO technical documentation for supported output module types) before ordering. The MC-TM400K2DMC is a non-intelligent component; it does not communicate with the NVR or access-control panel, making it suitable for retrofit installations where firmware updates or VMS platform changes pose no risk of compatibility loss.
Deployment considerations include wire gauge rating (ensure cable cross-section matches the module's current capacity) and operating temperature range. Install the module in a protected enclosure if the output cable will experience extended exposure to moisture, extreme heat, or UV radiation. In harsh-environment installations (outdoor gate controllers, rooftop strobes), house the module inside the recorder cabinet or a separate DIN-rail enclosure rather than exposing it to weather. The passive PTC element has no maintenance cycle — no battery backup, no calibration, no firmware patches.
Marty AllisonPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've specified the i-PRO MC-TM400K2DMC across dozens of mixed-use installations where long cable runs to door strikes, gate controllers, and alarm strobes created recurring surge damage. The real value isn't in protecting against one catastrophic lightning strike — that's what surge suppressors on power supplies handle. The MC-TM400K2DMC solves the chronic problem: nuisance surges from AC induction on unshielded control cables, relay chatter inducing back-EMF spikes, and wiring faults in wet environments that quietly degrade a control board over time. Because it's passive and self-resetting, integrators can deploy it on retrofit projects where firmware changes or VMS migrations aren't feasible. We've also seen it reduce warranty claims and callback visits — a $50 module on a door-strike output prevents a $1,500 board replacement and a 48-hour service delay. The tradeoff: you need to know which outputs matter most. Protecting every relay output adds cost; protecting critical paths (main entry, emergency exit, backup gate) is the sweet spot.
Technical Highlights:
- Self-Resetting PTC Element: Unlike traditional fuses, the PTC automatically restores operation once the fault is cleared. In outdoor gate-control installations, this means a surge from nearby lightning doesn't require a technician to drive out and replace a fuse — the system recovers automatically within milliseconds.
- No Configuration Footprint: Operates entirely at the hardware level with no firmware involvement. This is essential on legacy i-PRO recorders where firmware updates are infrequent or unavailable — the module continues protecting regardless of recorder age or VMS platform.
- Dual-Voltage Rating (12 VDC / 24 VDC): Most i-PRO control outputs run at one of these voltages. The module's dual-voltage design eliminates SKU proliferation and makes stockkeeping simpler for integrators supporting heterogeneous deployments.
- Inline Installation: Connects between output terminals and load — no rewiring of control circuits required. On retrofit jobs where modifying existing wiring creates liability, the inline approach keeps change scope minimal.
- Passive Power Draw: The PTC element consumes essentially zero power during normal operation. No hidden current draw that could affect relay duty cycles or contribute to board heat dissipation in a crowded cabinet.
Deployment Considerations:
- Always specify which outputs the module will protect. Don't default to protecting all relay outputs — prioritize main entry doors, emergency exits, and outdoor gate controllers where surge risk is highest and recovery time is critical.
- Verify recorder model compatibility before ordering. i-PRO output modules are not cross-compatible across all product lines. Check the specific recorder's technical manual for supported module types.
- In installations with very long cable runs (>150 feet to outdoor loads), pair the MC-TM400K2DMC with shielded control cable and proper grounding to minimize induction risk. The module protects against faults, but good wiring practice prevents faults from occurring in the first place.
- Install in a controlled environment (inside the recorder cabinet or a DIN-rail enclosure) rather than mounting the module outdoors. PTC elements have operating temperature limits; extended exposure to direct sun or freezing conditions may degrade response time.
- Document which outputs are protected in the system as-built drawing. Future technicians need to know whether a particular relay output has inline protection — affects troubleshooting and spare-parts planning.
The MC-TM400K2DMC is the right choice for integrators building redundant or mission-critical access-control integrations where unplanned board failures create high operational costs. Pair it with a robust power supply and shielded cabling strategy, and you've substantially reduced the failure modes that plague long-term surveillance deployments. For more i-PRO control modules and integration accessories, visit the i-PRO catalog.
