Description

New product. High-insulation MEDER LI12-1A85 reed relay, from the new generation, with visible U4/2 marking, designed for switching measurement and control circuits where compact dimensions and high switching voltage are required, a high-insulation component used in insulation resistance monitoring (RISO) circuits of specific Aurora, ABB, and FIMER photovoltaic inverters from 3 kW up to 12.5 kW. The LI12-1A85 model belongs to the LI series by MEDER/Standex-Meder.

⚙️ Technical Specifications

• Brand: MEDER
• Model: LI12-1A85
• Visible marking: U4/2
• Type: SPST-NO – 1 Form A reed relay
• Coil: 12 V DC
• Coil resistance: 680 Ω
• Coil current: approx. 17.5 mA
• Contact current: 1 A
• Maximum switching voltage: 1000 V AC / 1000 V DC
• Switching power: 100 W
• Mounting: THT / through-hole
• Housing: hermetically sealed
• Operate voltage: 8.4 V DC
• Release voltage: 1.8 V DC
• Operate time: approx. 1 ms
• Release time: approx. 0.1 ms
• Operating temperature: −20…+70 °C

⚡ Function in the Electrical System

The LI12-1A85 is designed for switching high-voltage signals and circuits while maintaining high insulation between the coil and contacts. The LI series is specifically developed for high-voltage applications, test systems, measurement, and photovoltaic applications.
The LI12-1A85 model is also documented as equivalent to the MEDER LI12-BV14072 relay, used in specific RISO control circuits of Aurora/ABB/FIMER photovoltaic inverters.

🏭 Construction and Installation

Compact relay with sealed blue housing and terminals for direct PCB mounting. The hermetically sealed reed construction provides good separation between the control circuit and the switched circuit. For replacement on an electronic board, it is necessary to respect the pinout, coil voltage, and insulation characteristics of the original component.

🛡️ Safety and Product Condition

The component is NEW, with body and terminals intact, as visible in the photographs. The switching capability of up to 1000 V AC/DC requires particular attention during use: the relay must only be used within the limits specified by the circuit and the relevant electronic board.

📦 Package Contents

• 1 × MEDER LI12-1A85
• New component, as shown in the photographs.

🚀 Final Description

MEDER LI12-1A85 is a 12 V DC SPST-NO reed relay, with high insulation and PCB mounting, featuring 1 A contact current and switching voltage up to 1000 V AC/DC. The original MEDER U4/2 – LI12-1A85 marking is clearly visible on the component. It is particularly suitable as a replacement for electronic circuits used for measurement, control, and insulation monitoring, including applications in photovoltaic inverters.