NEWSHEET10

TRANSFORMER PROTECTION

The risk of Overheat and/or Fire conditions on Power Transformers and Generator sets remain high - even where regular maintenance programmes are operated and where shielding, grounding and lightning arrestor devices are installed . With fire detection or protection (combined detection + extinguishing) systems generally specified or recommended by site operators and plant manufacturers. The primary sources of fires vary of course - depending upon whether the risk is a transformer or Generator, and includes overheating/ignition of diesel, dirty insulators, insulation deterioration which produces arcing and an associated overheat of the insulating oil - causing the tanks to rupture - which in turn produces further arcing and the commencement of a fire . Plus, lightning stikes on transformer units.

The most effective detection of the overheat condition (pre- combustion) or the fire itself is by DIGITAL LINEAR HEAT DETECTION. A combined detector and cable in one which monitors local temperature changes, and is able to operate continuously within adverse environments and areas of limited access and surveillance. The fixed temperature ( non length dependant) line based system can be installed either directly onto the device it is protecting via plastic cable ties and mounts, or to very local extinguishing pipework (where installed), and should be routed around all sides of the transformer or generator at BOTH top and bottom levels in order to maximise protection and ensure fastest response times .

Linear Heat sensor cables supplied and/or manufactured by PROLINE PROTECTION SYSTEMS LTD, are colour coded for alarm temperature verification, flame retardant, corrosion and abrasion resistant (as standard), and offer U.L. listing or F.M. approvals as a minimum. When used in conjunction with an optional dedicated interface unit, they can also provide "alarm point location" facilities (the identification by integral meter of the exact alarm point along a zone run of sensor cable - with any interconnecting cabling calibrated out) - Of particular advantage on pre-combustion detection situations where no visible flame exists!