Janitza CT27-35 current transformer 35/1A class 1 1503080

Electrical engineers and panel builders use the Janitza CT27-35 current transformer to measure AC current in low-voltage distribution systems. This ring-type transformer converts a primary current of 35 A to a secondary current of 1 A, enabling safe connection to energy meters and power analyzers. Its 27 mm aperture accommodates common cable sizes, and the compact design fits easily into crowded enclosures.

Key specifications

• Primary current: 35 A
• Secondary current: 1 A
• Accuracy class: 1
• Rated burden: 0.2 VA
• Max. conductor diameter: 27 mm
• Frequency: 50/60 Hz
• Rated insulation voltage: 0.72 kV
• Test voltage: 3 kV
• Overcurrent limiting factor: FS5
• Thermal short-time current: 2100 A (1s)
• Dynamic short-time current: 5250 A
• Insulation class: E
• Operating temperature: -5°C to +50°C
• Storage temperature: -25°C to +70°C
• Protection class: IP20
• Mounting: cable tie, base plate, DIN rail (with adapter)

Why choose it

The CT27-35 delivers reliable measurement with Class 1 accuracy and a low burden of 0.2 VA, reducing errors in metering circuits. Its wide operating temperature range and robust insulation make it suitable for industrial environments.

Ideal use cases

• Energy monitoring in distribution boards
• Sub-metering for commercial buildings
• Power quality analysis with Janitza meters
• Retrofit installations where space is limited

Good to know

The transformer is designed for indoor use only (IP20) and must be installed by qualified personnel. Always short-circuit the secondary terminals when the primary is energized to avoid dangerous voltages.