Under-Bushing Tap Changer
A tap changer beneath transformer bushings allowing adjustment without entering the oil tank.
An under-bushing tap changer (UBTC) is a de-energized tap changer beneath HV bushings, with selector in oil space below.
Common on distribution transformers. Accessible from outside tank without draining oil. Advantages: compact, external access, no extra penetrations. Requires de-energization. Range: typically +/-2x2.5%.
QDTB uses UBTCs on distribution transformers where simplicity and cost-effectiveness are priorities.
Related Products
Related Terms
Tap Changer
A device adjusting transformer turns ratio by connecting to different tap points on a winding.
Bushing
An insulated device allowing a conductor to pass through a grounded barrier while maintaining insulation integrity.
Turns Ratio
The ratio of primary to secondary winding turns directly determining voltage transformation ratio.
More in “Components & Accessories”
Bushing
An insulated device allowing a conductor to pass through a grounded barrier while maintaining insulation integrity.
Busbar
A metallic strip conducting electricity within switchgear, transformers, and distribution equipment.
HV/LV Bushing
High-voltage and low-voltage insulated conduits for transformer winding connections through the grounded tank.
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