JST is one of the world's largest and most reputable manufacturers of medium-voltage cast resin transformers from 150 kVA to 20,000 kVA. Below is some basic information about our products:

Design
JST transformers use the proven May-Christie type design, employing a core cruciform construction with a mitered step lap.

Features

• Both HV & LV windings vacuum cast in epoxy
• Step-lap mitered cruciform core
• 185°C cast epoxy insulation system
• Vibration isolators protecting core and coil

Specifications

• Primary voltages up to 34.5 kV
• UL Class H insulation systems – 185°C
• Temperature rises of 115°C and 80°C
• Basic Impulse Levels (BILs):
  > Primary: 60 kV – 200 kV
  > Secondary: 10 kV – 95 kV

Standards
Our transformers meet the standards of:

• IEEE/ANSI
• IEC
• CSA
• UL
• NEMA

Coils
Our coils, both primary and secondary, are fully cast in epoxy resin. This achieves the highest mechanical strength, dielectric strength, and reliability.

Enclosures
We use a knock-down type enclosure made of cold rolled steel and finished with electrostatic powder paint.

Options
Available options include:

• Indoor or outdoor enclosures
• With or without fans