UZ Series Tap-changers Technical guide
Key attributes
| Brand | Transformer Parts |
| Model NO. | UZ Series Tap-changers Technical guide |
| Methods of regulation | Central voltage regulation |
| Series | UZ Series |
Product descriptions from the supplier
Overview
On-load tap-changer (OLTC)
The UZ types of on-load tap-changers operates according to the selector switch principle, that is, the tap selector and diverter switch functions are combined in one. The tap-changer is built-up by using single-phase units, each identical, mounted in the openings on the rear of the compartment. Each singlephase unit consists of an epoxy-resin moulding, a selector switch, transition resistors and, in most cases, a change-over selector.
The UZ types of tap-changers are mounted on the outside of the transformer tank. All of the equipment necessary to operate the tap-changer is contained in a single compartment, with the motor-drive mechanism attached to the outside. Because the UZ types are designed for mounting on the outside of the transformer tank installation procedures are simplified and the overall size of the transformer tank can be reduced.
Standard tanks are designed for the UZ types. The standard tanks have a number of standard flanges to get great flexibility for accessories. Standard accessories are pressure relay and oil valve, and a great number of extra accessories can be ordered. See Figs. 09 and 10.
As a design option, the UZ types can be supplied without the tank. This gives the transformer manufacturer the flexibility to design the tap-changer tank as an integral part of the transformer tank.
The oil should be of class II according to IEC60296, 2012-02.
Related Products
Related Knowledges
-
Faults and Handling of Single-phase Grounding in 10kV Distribution LinesCharacteristics and Detection Devices for Single-Phase Ground Faults1. Characteristics of Single-Phase Ground FaultsCentral Alarm Signals:The warning bell rings, and the indicator lamp labeled “Ground Fault on [X] kV Bus Section [Y]” illuminates. In systems with a Petersen coil (arc suppression coil) grounding the neutral point, the “Petersen Coil Operated” indicator also lights up.Insulation Monitoring Voltmeter Indications:The voltage of the faulted phase decreases (in01/30/2026 -
Neutral point grounding operation mode for 110kV～220kV power grid transformersThe arrangement of neutral point grounding operation modes for 110kV～220kV power grid transformers shall meet the insulation withstand requirements of transformer neutral points, and shall also strive to keep the zero-sequence impedance of substations basically unchanged, while ensuring that the zero-sequence comprehensive impedance at any short-circuit point in the system does not exceed three times the positive-sequence comprehensive impedance.For 220kV and 110kV transformers in new constructi01/29/2026 -
Why Do Substations Use Stones, Gravel, Pebbles, and Crushed Rock?Why Do Substations Use Stones, Gravel, Pebbles, and Crushed Rock?In substations, equipment such as power and distribution transformers, transmission lines, voltage transformers, current transformers, and disconnect switches all require grounding. Beyond grounding, we will now explore in depth why gravel and crushed stone are commonly used in substations. Though they appear ordinary, these stones play a critical safety and functional role.In substation grounding design—especially when multiple gr01/29/2026 -
Why Must a Transformer Core Be Grounded at Only One Point? Isn't Multi-Point Grounding More Reliable?Why Does the Transformer Core Need to Be Grounded?During operation, the transformer core, along with the metal structures, parts, and components that fix the core and windings, are all situated in a strong electric field. Under the influence of this electric field, they acquire a relatively high potential with respect to ground. If the core is not grounded, a potential difference will exist between the core and the grounded clamping structures and tank, which may lead to intermittent discharge.I01/29/2026 -
Understanding Transformer Neutral GroundingI. What is a Neutral Point?In transformers and generators, the neutral point is a specific point in the winding where the absolute voltage between this point and each external terminal is equal. In the diagram below, pointOrepresents the neutral point.II. Why Does the Neutral Point Need Grounding?The electrical connection method between the neutral point and earth in a three-phase AC power system is called theneutral grounding method. This grounding method directly affects:The safety, reliabilit01/29/2026 -
What’s the Difference Between Rectifier Transformers and Power Transformers?What is a Rectifier Transformer?"Power conversion" is a general term encompassing rectification, inversion, and frequency conversion, with rectification being the most widely used among them. Rectifier equipment converts input AC power into DC output through rectification and filtering. A rectifier transformer serves as the power supply transformer for such rectifier equipment. In industrial applications, most DC power supplies are obtained by combining a rectifier transformer with rectifier equ01/29/2026
