SOP: ELECTRICAL HEALTH | FRANCIS UNIT 1
SOP-DIAG-002 REV 2.0

ELECTRICAL HEALTH & INSULATION

INVISIBLE DEGRADATION

HIGH VOLTAGE ALERT

Generator windings (6.6-11kV) degrade invisibly. Insulation breakdown causes "Slot Discharge" and total winding failure. A stator rewind costs >$100,000 and months of catastrophic downtime.

CORONA DETECTION

OZONE SMELL AUDIT

Detect sharp, chlorine-like smell at air exits when unit is at >70% load. Indicates active high-voltage discharge.

WHITE POWDER FORMATION

Visual grey/white residue in winding slots is a byproduct of resin breakdown by ozone (Bushing Corona).

THERMAL BUDGET

Class Cont. Max Hot Spot
Class B 130°C 145°C
Class F 155°C 170°C

Typically, 1.3MW units use Class F insulation. Normal operating rise should remain ~110°C.

INTERLOCK: HEATER & BREAKER

CRITICAL MOISTURE RULE:

Anti-condensation heaters MUST activate within 5s of Main Breaker opening. 48h shutdown in tropical humidity without heaters = insulation drop from 100MΩ to <1MΩ (DANGER).

BREAKER OPEN
HEATER ACTIVE