The Victron Energy UFR1001E Anti‑Islanding Relay (SKU REL100100000) is a highly reliable protection device designed for PV, hybrid and battery‑storage systems. It continuously monitors voltage and frequency on the grid to detect islanding conditions: when your system is still supplying power despite a loss of the public grid, and disconnects accordingly to maintain regulatory safety.
This relay supports a wide voltage measurement range, from 15 V up to 520 V phase‑neutral and up to 530 V phase‑phase, giving it flexibility for varying grid and inverter configurations. It also tracks under- and over-frequency (45–65 Hz) as well as vector shift (2°–65°) and rate of change of frequency (ROCOF), which helps it respond quickly and safely to grid instability.
The UFR1001E is a dual‑channel unit, meaning it is “one-fault-proof”: if one monitoring channel fails, the other continues to provide protection. It includes two change-over relay outputs that allow remote shutdown and safe reconnection, and it provides feedback contacts so switching behaviour can be verified.
You can program the relay’s switching delay (0.05–300 s) and the switch-back delay (0–6000 s) to customise performance to local grid code requirements or site-specific behaviour. It features a test button and simulation mode so installers can commission easily, and it keeps a record of up to 100 alarms, including timestamped reasons.
Designed for trade and professional installations, the relay mounts on a 35 mm DIN‑rail and is compact (approx. 90 × 105 × 69 mm) and lightweight (around 250 g). Its operating temperature range is –20 °C to +55 °C, and it has an IP30-rated housing with IP20 terminal protection.
The UFR1001E meets stringent grid-safety standards: it is certified for VDE‑AR‑N 4105 (2018), VDE‑AR‑N 4110, G98 and G99 (UK), ÖVE / ÖNORM, DIN V VDE 0126‑1‑1, and others. This makes it suitable for use in a wide range of jurisdictions and installations that require formal anti-islanding protection.
