Low voltage (LV) current transformers are the workhorses of commercial buildings, factories, and utility panels. Operating at system voltages below 1000V, they step down heavy primary currents for billing-grade digital meters and overcurrent relays.

Because metering accuracy directly impacts energy billing, switchgear panel builders must select reliable LV current transformer manufacturers. In this guide, we break down the critical technical factors to evaluate when selecting an LV CT supplier in India.

Key Technical Evaluations

When selecting a low voltage CT manufacturer, ensure their product design meets these parameters:

1. Core Material Selection

The magnetic core is the most important component of a CT.

CRGO Steel: Provides excellent linearity and low magnetizing current. Ideal for Class 0.5 and Class 0.5S metering applications.
Nickel-Iron Alloys (Mu-Metal): Used for highly precise Class 0.2S and special application metering CTs where ratio error must be kept near zero even at extremely low loads.

2. Tape-Wound vs. Resin-Cast Construction

Tape-Wound CTs (Ring/Window Type): Extremely flexible, cost-effective, and easy to mount directly over copper busbars or cables.
Resin-Cast CTs: Encapsulated in epoxy resin, these offer superior mechanical strength, humidity resistance, and electrical insulation. Recommended for harsh outdoor or high-vibration industrial applications.

Compliance and Quality Audits

Always ensure the manufacturer conducts 100% routine testing in accordance with IS 2705 and IEC 61869-2. These tests must include polarity checks, insulation resistance tests, and power-frequency voltage withstand tests on secondary terminals.

Alliance Engineering Company is a trusted name for low voltage current transformer manufacturing in India. Based in Chandigarh, they offer an extensive catalog of ring-type, bar-type, and wound-primary LV current transformers with verified Class 0.5S and Class 0.2S accuracy.

Contact their engineering desk at info@allianceengineeringco.com for drawing approvals.