6kV 10kv 12KV 15KV 20KV 33KV indoor MV current transformer for instruments

6KV 10KV 12KV 15KV 20KV 33KV indoor MV current transformer for instruments

General Description

GFUVE manufactures an extensive line of cast epoxy resin insulated transformers across the voltage range of 5.5 KV to 72.5 kV. This brochure describes one model of outdoor Current Transformers in the 36kV class with performance ratings coinciding with industry standard product offerings. GFUVE, because of product depth, familiarity with international standards and custom design capability can also design according to customer specific needs.

Construction

The toroidal core and winding assembly is encapsulated in cycloaliphatic epoxy resin in a single process, performed under vacuum, using the pressure gelation method. The resin color is grey. Brown is available by special order. Epoxy resin was chosen because of its excellent tracking resistance, high mechanical strength, ability to withstand ultraviolet radiation, superior weathering characteristics and its noncombustibility.

Thermal & Dynamic Rating

For designs up to 600A the short time thermal rating is 100 times nominal current for 1 second and above 600A it is 63kA/1second. The dynamic short time rating is 2.5 times the thermal rating.

Primary Terminals

Primary terminals are flat tin plated copper NEMA two hole pads. Primary terminals are detachable so that alternate terminal configurations can be considered. Maximum allowable terminal pull is 1100lbs.

Secondary Terminals

Secondary terminals are bronze clamp type with a large diameter hole. A bronze pivoting short circuit device is an integral part of the secondary terminal arrangement. A ground terminal is also provided.

Terminal box

The cast aluminum terminal box has one inch conduit hubs on both ends and a knock out for a one inch conduit fitting on the bottom. The box is attached to the transformer body by four bolts in an industry standard pattern and can easily be detached, simplifying change out procedures.

Base Plate

The base is made of marine grade aluminum and is securely attached to the transformer body. Industry standard mounting dimensions and a single hole ground pad 90° to the mounting plate are provided.

Nameplates

Nameplate data is engraved on blackened stainless steel plates

Mounting

The transformers can be mounted in the horizontal, vertical or suspended position.

Tests

Routine tests in compliance with IEEE are standard. In addition internal partial discharge is performed as a routine test with acceptance criteria of < 20pC at 1.2Vm/√3 and <50pC at 1.2 Vm. Test cards are included with each unit.

Commissioning and Maintenance

Transformers are supplied ready for service. No special tools are required. Instruction manuals are provided with each shipment. Periodic wiping down of the units with silicone grease is recommended.