A6901

The Tektronix A6901 Ground Isolation Monitor connects between mains power and test equipment without connecting protective ground, in order to safely allow referencing measurements to a low voltage instead of ground, or break ground loops.

Tektronix A6901
Ground Isolation Monitor Tektronix A6901 Ground Isolation Monitor Produced from 1981 to (?) Manuals Tektronix A6901 Manual (PDF) (All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

It monitors the floating equipment ground voltage. If the voltage exceeds 40 V peak, or ground current exceeds a selectable limit of 0.5, 3.5 or 5 mA, the A6901 disconnects mains power and grounds the test equipment.

Key Specifications

DC trip voltage	28 V_RMS (40 V peak) or ±40 V DC
Current trip	±0.5 mA, ±3.5 mA and ±5 mA max. selectable
Trip delay	<200 ms
Line voltage	90-128 V; 180-250 V; 48-66 Hz
Load power	500 W max.

Operating principle (click to enlarge)