Service and Maintenance 8E364xA User’s and Service Guide 209CV source effect (line regulation)This test measures the immediate change in the output voltage that results from achange in the AC line voltage from the minimum value (10% below the nominalinput voltage) to the maximum value (10% above the nominal input voltage).1 Turn off the power supply and connect a digital voltmeter between the (+) and(–) terminals of the output to be tested as shown in Figure 8-1.2 Connect the AC power line through a variable voltage transformer.3 Turn on the power supply. Select the high voltage range (20 V/1.5 A)[1], enablethe output, and set the display to the limit mode. When the display is in thelimit mode, program the current to the maximum programmable value and thevoltage to the full-scale rated value (20.0 V) [1].4 Operate the electronic load in the constant current mode and set its current to1.5 A [1]. Check that the CV annunciator remains lit. If not lit, adjust the load sothat the output current drops slightly until the CV annunciator lights up.5 Adjust the transformer to the low line voltage limit (104 Vac for nominal 115Vac, 90 Vac for nominal 100 Vac, or 207 Vac for nominal 230 Vac). Record theoutput reading on the digital voltmeter.6 Adjust the transformer to the high line voltage (127 Vac for nominal 115 Vac,110 Vac for nominal 100 Vac, or 253 Vac for nominal 230 Vac). Record thevoltage reading on the digital voltmeter immediately. The difference betweenthe digital voltmeter readings in steps 5 and 6 is the CV line regulation. Thedifference of the readings during the immediate change should be within thelimit of 5 mV[2] or 9 mV[3].[1] For the E3640A model. For other models, refer to Table 8-5.[2] For the E3640A/E3642A/E3644A model.[3] For the E3641A/E3643A/E3645A model.
