4-2
4.1 TEST METHODS
4.1.1 Insulation Resistance Test
FIGURE 3: Insulation Resistance Test ID Screen
Enter an alphanumeric test identification (or leave blank) and press enter.
FIGURE 4: Insulation Resistance Test Setup Screen
The Insulation Resistance (I.R.) Test Setup Screen (Figure 4) displays prompts for test time in minutes,
maximum voltage to apply, and maximum allowed current for the Overcurrent Trip. Type in test time, in
minutes (1-60), or leave blank for continuous testing, then press enter. Proceed with voltage and current in
the listed units and press enter to confirm entry. Press enter to proceed to the Temperature Compensation
Screen.
FIGURE 5: Temperature Compensation Setup Screen
At the Temperature Compensation Setup Screen (Figure 5), the operator can choose to activate the internal
buzzer to sound during the test. Inputs are Y for buzzer on and N for buzzer off. Users can then define a
base temperature to correct resistance measurements to, as well as the actual temperature of the test object.
These fields must be completed, as leaving them blank does not bypass the temperature compensation
function of the unit. It is recommended not to correct to a temperature more than ± 20°C from the test
objects temperature, as this could cause significant error in the resistance reading. Once the Temperature
Compensation screen is filled out, press Enter to bring up the HV Waiting Screen.
SPECIAL NOTE ON TEMPERATURE EFFECTS:
Even the best insulation has a small amount of resistive leakage current. With aging and deteriorating of
some insulation system (motors, transformers and paper oil insulated cables), this leakage current will
increase, which can aid in assessing the quality and remaining lifetime of the insulation system. In order to
achieve the most consistent results it is important to correct the test object temperature to a standard
temperature, usually (40°C or 68°F). The PM15-4A has the capability to perform this calculation automatically
by entering the test object temperature. The built in printer function allows the operator to document the