General Electric Multilin’s UR-8LH is a CT/VT module designed for the general purpose relay family. This module can be used to replace the current module, upgrade the current module, or provide new functionality for generic relays not originally supplied with a given module. This particular module provides 4CT/4VT for relays with enhanced diagnostic capabilities.

A variant of this module, the UR-8LH, is equipped with enhanced diagnostic capabilities that provide many benefits to power systems. First, the module is able to verify the integrity of the analog signal and ensure reliability. The module does this by adopting an advanced algorithm that can determine if the signal is functioning properly.

The CT/VT transformer pinpoints the current and voltage values to those that the relay can handle, allowing it to calculate the ratio of the output value to the current and voltage. This function is essential for identifying dangerous voltage and current conditions within the system and establishing an appropriate response. This data can be viewed through the LCD display on the front panel or through a computer running the EnerVista UR software program.

About UR-8LH
UR-8LH is a CT/VT module (current transformer and voltage transformer) in some general purpose relays. Each universal relay contains a CT/VT module, a CPU, a power supply, an IEC process bus, relay-to-relay communication, a communication switch, a digital I/O, and a sensor I/O. The CT/VT module can contain up to 24 signals for AC power line monitoring functions. Some CT/VT modules even have sensitive ground inputs for ground fault protection. If this is the case, the order number specifies that this feature will be provided for the device. The Multilin UR-8LH’s order specifications include standard 4CT/4VT functionality, but with enhanced diagnostic capabilities. The 8G, 8J, 8M and 8R CT/VT modules feature sensitive ground fault protection. The UR-8LH is a new CT/VT module, so it should be paired with a new CPU to avoid hardware mismatch errors. Firmware versions of at least 4.0x are compatible with new cpus and new CT/VT modules. In contrast, general-purpose relays require firmware versions of 3.4x or earlier firmware versions to be compatible with older cpus and CT/VT modules.