Conclusion

CT/VT modules with enhanced diagnostics, released on 23 October 2006 with firmware 5.2.

offer much higher security for internal CT/VT module error detection and prevent undesired operations of URs.

Every UR firmware released since version 5.2 supports CT/VT modules with enhanced diagnostics,

which greatly improves the security and reliability of the protection system.

To take advantage of this feature, a relay hardware and possibly firmware upgrade is required.

If the existing relay has a firmware version below 4.0. GE recommends purchasing a

UR Upgrade Kit that allows modernization of the obsolete relay hardware

while taking advantage of the relay modularity.

The UR Upgrade Kit contains a new CPU and CT/VT modules that can be

inserted in an existing relay case (case is fully backwards compatible).

If the relay currently has firmware version 4.0 to 5.0. the latest firmware

can be downloaded from the GE Multilin website, and Enhanced Diagnostic

CT/VT modules (8L, 8M, 8N, 8R, 8S, 8V) can be purchased from the GE Online Store.

Consult with your local GE representative if you have any questions on the upgrade process.