UR9DH CT/VT Module UR Series GE

The UR-9DH is a CPU contained in many of the universal relays of the UR series Multilin products. The UR-9DH is of the older generation of CPUs, as the letter following the ‘RH-9’ designation indicates the age of the modules (in general), with letters over the ‘9D’ options indicating the newer CPUs. Thus, the UR-9DH is an older module with a RS485 and a redundant 10Base-F (Ethernet, Modbus TCP/IP, DNP). The new version CPU with these same features is the RH-9H CPU. In the case of the F35 multiple feeder protection system, it is important to insure that the CPU age matches the age of the CT/VT module. Thus, an older model CPU must be matched with an older CT/VT module within the same universal relay or an error code will prevent the function of the UR relay unit. The old CT/VT modules are the 8A, 8B, 8C, and 8D alphanumeric designations. An 8A CT/VT has the standard 4CT/4VT characteristics, where an 8B CT/VT has a sensitive ground component of 4CT/4VT. The 8C CT/VT module has standard 8CT features and the 8D has the sensitive ground 8CT features.