Mitton Instruments | Low Current Injector

The Low Current Injector (LCI) provides a reliable method for testing earthing/grounding systems, particularly those with low impedance (< 2 ohms) or which are extensive and where noise is present on the earthing system.

Portable earth testers are often unsuited to testing such earthing/grounding systems due to limited test current and inadequate noise rejection.

The LCI method injects a known current into the earth grid. The test current frequency is 58 Hz*. This provides a very unique test condition and the 58 Hz signal can be easily identified during the tests. Combined with the use of tuned voltmeters (58 Hz), the earth grid characteristics including impedance, touch, transferred, step voltages can be determined.

The LCI unit provides a constant current. This is necessary for accurate testing and overcomes the phenomena of current variation due to the time varying resistance of the remote test probes due to localised soil heating.

Auto shut-off is a safety feature that ensures the injected current immediately ceases should the injection circuit be interrupted.

The LCI output is galvanically isolated from the input supply.

In some cases it is impractical to use the LCI, for example where the injection is carried out using an existing power or transmission line running parallel to another line. In such cases the induced current in the test circuit may be excessive. However, a diesel genset can be used instead.

*52 Hz model available for 60 Hz systems

Specifications

Power Supply: 230 V AC 50/60 Hz (mains or genset)
Output Current: 1 -10 A constant current
Protection: Auto shutdown on open circuit
Output frequency: 58 Hz (50 Hz systems) 52 Hz (60 Hz systems)
Housing: Robust Pelican Case
Weight: 17 kg