10 kV SC(B)11–SC(B)18 Epoxy Cast-Resin Dry-Type Transformer

Overview

The 10 kV SC(B)11, SC(B)12, SC(B)13, SC(B)14 and SC(B)18 epoxy cast-resin dry-type transformers are low-noise, low-loss distribution units. They replace oil-immersed distribution transformers in urban grids, high-rise buildings, business centres, tunnels, metro lines, stations, ports, airports and underground substations.

Features and advantages

• Safe and flame-retardant: the coils are packed with glass-fibre mat and cast under vacuum in unfilled epoxy resin; they are self-extinguishing, produce no arc on short circuit and release no toxic gases at high temperature, which suits sites with high fire-protection requirements.
• Environmental resistance: the coils do not absorb moisture and the core clamping parts carry a special anti-corrosion coating, so the unit can operate at 100% relative humidity and in harsh environments without drying out after intermittent operation.
• Electrical performance: high mechanical strength, low partial discharge and good withstand capability against short circuits and lightning impulses.
• Easy and economical to install: small, light and space-saving, with no need for an oil pit or elaborate fire-fighting facilities; units can be distributed across load centres, reducing cable costs.

Enclosure

Enclosures are made of stainless steel or aluminium alloy with degrees of protection IP20 and IP23. IP20 prevents the ingress of solid objects larger than 12 mm; IP23 additionally prevents water falling at up to 60° from the vertical and allows outdoor operation. Note: an IP23 enclosure reduces cooling capability by about 5% on small ratings and about 10% on large ratings.