Fluke 1503 FE 1503-1507 Users Manual - Page 21

Measuring Insulation Resistance Insulation tests should only be performed on de-energized circuits. To measure insulation resistance set up the Tester as shown in Figure 7 and follow the steps below: 1. Insert test probes in the V and COM input terminals. 2. Turn the rotary switch to the desired test voltage. 3. Connect the probes to the circuit to be measured. The Tester automatically detects if the circuit is energized. • The primary display shows - - - - until you press T and a valid insulation resistance reading is obtained. • The high voltage symbol (Z) along with a primary display of >30 V warns if voltage more than 30 V ac or dc is present. In this condition, the test is inhibited. Disconnect the Tester and remove power before proceeding. Insulation Testers Making Measurements 4. Push and hold T to start the test. The secondary display shows the test voltage applied to the circuit under test. The high voltage symbol (Z) along with a primary display showing the resistance in MΩ or GΩ appears. The t icon appears on the lower portion of the display until T is released. When resistance is higher than the maximum display range, the Tester displays the Q symbol and the maximum resistance for the range. 5. Keep the probes on the test points and release the T button. The circuit under test then discharges through the Tester. The resistance reading appears on the primary display until a new test is started or a different function or range is selected or > 30 V is detected. 13