On-Load Tap Changers: AT and ATV ranges

BRUSH continues to supply the amalgamated Associated Tapchangers range. Based on high-speed resister transition, this three-phase system provides a bolt-on solution for voltages up to 66kV on line end, and 132kV on neutral end and nominal rated current up to 300A. 


The BRUSH range of single compartment units with high-speed resistor transition is designed for three-phase systems with voltages up to 66kV line end or 132kV neutral end and nominal rated current of 300A, 400A for linear regulation.

AT & ATV tap changers have a maximum of 17 tapping positions (16 steps) 15 possible for linear regulation and 33 tapping positions (32 steps) for reversing of course/fine regulation.

AT OLTCs are capable of reverse flow at full power. The OLTCs are a flange-mounted tapchangers where the oil in the switch compartment is kept separate at all times from the oil in the main transformer.

Manufactured in accordance with IEC 60214 and also complies with many other national and international standards.

Key benefits

Installation & commissioning support
Reversed powerflow
Asset maintenance & upgrades
Lower cost of ownership

Technical Specifications

AT & ATV Tapchangers
Linear, reversing or coarse/fine versions
Suitable for 52kV, star or delta windings
400A version (linear only)
Suitable for 145kV star winding (neutral end only)
Single-phase version available
Vertically-mounted option also available
Bi-directional power flow
High speed resistor on-load selector switch
Ease of maintenance
Low oil content
Up to 17 positions (linear) or 33 positions (reverse or coarse/fine)
Fully automatic or manual operation
Can be mounted horizontally (AT) or vertically (ATV)


Whether your requirements call for a DNO approved transformer or a bespoke solution, BRUSH covers the vast majority of applications.

Legacy Tap Changers

We hold extensive records of legacy products supplied by BRUSH, Fuller, Hawker Siddeley and ATL. We are therefore uniquely placed to offer full support for spares, service and refurbishment. We can support:

  • BRUSH type HSR, HSRD
  • Fuller/Hawker Siddeley type EH, H, HD, HS, AN, AG, ASD, AMD
  • ATL type AT and ATV

Transformer Services

From initial system analysis, to design, engineering, supply, installation, commissioning and upgrades of equipment through to repurposing or decommissioning. We provide lifecycle management and support.

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Speak to our team

BRUSH has a global reputation for service excellence and dedicated customer support. With a wealth of experience spanning more than 145 years and significant in-house knowledge and expertise, our commitment to excellence is backed by experience and knowledge.

Whether it’s the provision of parts, the delivery of service support in the field, at the customer’s premises or at our network of service workshops, our team of highly experienced engineers are on hand to support.