Tesla MCI-2 High Current Mid-Circuit Interrupter, 15A Rapid Shutdown Device
SKUMCI-2 15A
The Tesla MCI-2 High Current is a mid-circuit interrupter (Tesla also calls it the Solar Shutdown Device). It installs within PV strings to meet the rapid shutdown requirements of NEC Article 690.12 and works as part of the Tesla Solar Inverter photovoltaic...
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Product Overview
The Tesla MCI-2 High Current is a mid-circuit interrupter (Tesla also calls it the Solar Shutdown Device). It installs within PV strings to meet the rapid shutdown requirements of NEC Article 690.12 and works as part of the Tesla Solar Inverter photovoltaic rapid shutdown system, per Tesla's install manual.
Tesla says MCI-2 and MCI-2 High Current differ only in their IMP and ISC ratings. This listing is the High Current version: 15 A IMP and 19 A ISC. The devices use power-line excitation and are normally open, so they open the string when the PV system AC breaker or disconnect is turned off.
Best For
- Tesla Solar Inverter PV systems that specify MCI-2 High Current: Strings with module currents up to 15 A IMP / 19 A ISC.
- Arrays covered by Tesla's UL 3741 listing: Tesla says MCI quantity and placement follow its UL 3741 Application Addendum.
Key Features & Specifications
| Specification | Details |
|---|---|
| Product type | Mid-circuit interrupter, PV rapid shutdown equipment (PVRSE) |
| Model | MCI-2 High Current |
| Nominal input DC current, IMP (per Tesla) | 15 A |
| Maximum input short-circuit current, ISC (per Tesla) | 19 A |
| Maximum system voltage (per Tesla) | 1000 V DC (Tesla Solar Inverter limits to 600 V DC) |
| Maximum disconnect voltage (per Tesla) | 165 V DC per MCI (additive in the same string) |
| Maximum MCIs per string (per Tesla) | 5 |
| Control; passive state (per Tesla) | Power Line Excitation; Normally open |
| Maximum power consumption (per Tesla) | 7 W |
| RSD initiation (per Tesla) | PV System AC Breaker or Disconnect |
| Certifications (as worded by Tesla) | UL 1741 PVRSE; UL 3741; PVRSA (Photovoltaic Rapid Shutdown Array) |
| Ambient temperature (per Tesla) | −45°C to 70°C (−49°F to 158°F) |
| Enclosure rating (per Tesla) | NEMA 4X / IP65 |
| Housing; dimensions (per Tesla) | Plastic; 0.9 × 6.8 × 1.8 in (22 × 173 × 45 mm) |
| Warranty (per Tesla) | 25 years |
| Source | Tesla Solar Inverter Install Manual, Mid Circuit Interrupter Specifications (P/N MCI-2) page, energylibrary.tesla.com, retrieved Oct 8, 2026; no revision number on page; Tesla Solar Shutdown Device Datasheet (Mar 2025; ul3741.com-hosted copy in sources, shows MCI-2 High Current 15 A / 19 A) |
What You May Also Need
Usually required
- A Tesla Solar Inverter: Tesla documents the MCI as part of the Tesla Solar Inverter rapid shutdown system.
- Tesla's UL 3741 Application Addendum: For the required MCI count and placement for your array type.
May be required
- Wire-management clips: Tesla shows MCI-2 clipped under the module frame, with clips 2–6 in (51–152 mm) from the MC4 connector.
- Other rapid shutdown parts: See rapid shutdown.
Optional upgrades
- None. Tesla lists no add-ons for the MCI itself.
Check current manufacturer documentation before combining components, especially batteries, inverters, communications equipment and system-control hardware.
Important Considerations
- Minimum count. Tesla warns that the minimum number of required MCIs must be installed. Where only one MCI per string is allowed, Tesla says MCI-1 must be used.
- Connectors. Do not twist the MC4 connectors on MCI-2; Tesla says this damages the contacts. Tesla calls for standard Stäubli Type MC4 connectors at the module connections.
- Clearance and string length. Tesla says to keep the MCI at least 1/2 in (12.7 mm) from the module glass or backside. Keep total DC circuit length within 160 m (525 ft) for single strings or 120 m (394 ft) for paralleled strings.
- Tesla systems only. Do not use with other string inverters unless Tesla documents it.