Siemens Services Technical Safety Bulletin SSTB 13-003
YMV VT Fuse Assembly – Corrosion Issues

Product: YMV Voltage transformer, fuse assembly
Production year affected: 1980 onwards
Modification Required: Inspection and repair to voltage transformer fuse assembly.
Priority of Change: Next planned maintenance


This product bulletin affects the Reyrolle 11kV, YMV; 1250A voltage transformer fuse assembly manufactured from 1980 onwards and has been the subject of ENA DIN 2007/0073/00 issued in August 2007.
It has come to our attention that some customers are experiencing dielectric failures of the voltage transformer fuse assemblies’ due to increased contact resistance caused by corrosion.

Although the risk of failure is classified as low, it is strongly recommended that during planned maintenance that the voltage transformer fuse assemblies are inspected for the presences of corrosion and if detected, necessary steps are taken to carry out a repair and address the atmospheric conditions to prevent re-occurrence.

The panel is to be removed from service and the voltage transformer fuse assembly withdrawn from the panel. Remove the fuse contact assembly and inspect the fuse assembly and if necessary clear any corroded parts. If the corrosion is excessive then the components will have to be replaced.

Spares can be obtained from Siemens Services Tendering Department.


Related Information

Photographs showing corrosion of the voltage transformer fuse assembly.

10/09/2013 | Author: Name