GW-Instek-GCT-630-Ground-Continuity-Tester-GW-Instek-GCT-630-P-The-GCT-630-is-a-special-purpose-safety-tester-focused-only-on-Ground-Continuity-testing-When-resistance-is-under-measurement-over-current-protection-can-be-set-from-3A-to-32A-with-a-plusmn-10-threshold-The-dual-meters-monitor-both-testing-current-&-resistance-in-real-time-The-GCT-630-has-settable-alarms-with-the-ability-to-stop-or-continue-tests-P-GCT-630-Ground-Continuity-Tester