Split Core CT with 1.25″ Opening by Magnelab

50-800 Aac input : 333 mVac output. 1.25″ opening

Product Description

Magnelab’s SCT-1250 is a Split Core CT that transforms an AC input current up to 800 Amps to a 0.333 Volt output.

The SCT-1250 is a Split Core CT with a 1.25″ opening. It has no hinges to break, making it durable. It’s unique opening mechanism has a self-locking mechanism and allows for easy installation around conductors.  This makes retrofitting existing installations simple.

Frequent Applications

  • Data logging
  • Recording
  • Power monitoring
  • Energy management
  • Cost allocation

Why the SCT-1250 split core CT?

The SCT-1250, like other split core CTs, is used to determine the current (measured in Amps) passing through a conductor (wire, bus bar, etc). This is needed, along with the voltage, to determine the amount of power being used (measured in kW). Click here for more information on monitoring.

As with most of Magnelab’s standard accuracy CTs, the SCT-1250 is 1% accurate when operating from 10% to 130% of the rated input current.  For example, given a 120A circuit breaker, the SCT-1250-100 would work well, because it will maintain its accuracy up to 130A (130% of the rated input).

The SCT-1250 has 7500 turns. If you purchase the unburdened option, you will see 13.33 mA on the secondary for every 100A on the primary.

Compatible power meters accept a voltage input.  Look for meters on our website that start with this symbol:


Looking for revenue grade with the same compact form factor? Try the SCT-125H for a 0.5% accuracy version of the SCT-1250. You can view all of our current sensors here.


  • Rated input up to 800 Amps
  • Output of 0.333 Volt at rated current Linearity accuracy +/- 1%
  • Accuracy at 10% to 130% of rated current
  • Phase angle < 2 degrees measured at rated current
  • Operates from 50 Hz to 400 Hz
  • 8 ft. twisted-pair lead
  • Maximum Voltage: 600 V (on bare conductor)
  • UL recognized, CE, and RoHS compliant
  • 7-Year Warranty

Data Sheet

 Technical Specs


UL Registered


Made in USA

ISO 9001

rohs compliant

Additional information

Weight.55 lbs
Dimensions3.75 x 3.75 x 2.0 in