KEPCO JQE 150-1.5MVPY-26956 Half Rack - Manual (Page 50)

6-4 JQE SPECIAL SVC 081111
• For remote operation, verify that EOUT LOC-REM switch is set to REM position
(towards rear panel). Verify that link between terminals RVC and RPV1 of TB501 on the
rear panel is removed. Verify remote programming resistor is connected between termi-
nals RPV1 and RPV2 of TB501 on the rear panel.
3. Input Circuit Breaker Trips During Operation
• Use properly rated (output current) twisted pair wires for power terminal (+V, –V) con-
nections as well as remote error sensing
• If remote error sensing is used, use properly rated (#22AWG recommended) twisted pair
wires for sense terminal (+S, –S) connections to the load.
• If the unit is operated at full power with maximum input voltage, check that the ambient
operating temperature surrounding the unit is within specified limits (see PAR 1.5).
• Verify that the pass-element transistors are tight to the heat sink and that silicone grease
was used beteen the transistor and heat sink. If problem recurs, replace thermoswitch
mounted on heat sink assembly.
4. If the power supply is basically functioning, but poor performance is evident, inspect the test
set-up to make certain the source of the trouble is not external.
5. Poor regulation in any of the regulating modes is usually traceable to incorrectly connected
loads or faulty measurement techniques. Perform measurements as described in Paragraph
6.4.2.
6. Oscillation of the output voltage or output current is often due to a load with a large inductive
component. Twisted load wires of sufficient diameter and held as short as practical, are often
the solution to the problem. Refer to to PAR. 4.3 for lag network adjustment.
7. Kepco Application Engineers are available for consultation or direct help in difficult service or
application problems.
6.4 POWER SUPPLY MEASUREMENTS
Measurement of the significant parameters of a power supply is a requirement for incoming
inspection, periodic maintenance, or after component replacement. Since the measurements
require special techniques to ensure correct results, suggestions for their performance are given
below.
6.4.1 REQUIRED TEST EQUIPMENT.
1. Constant AC supply voltage with provisions for "stepping" the voltage over a specified
region (105-125V); a variable autotransformer is generally adequate, if it is rated to
deliver the input current of the unit under test.
2. Resistive load, variable, with ON/OFF and SHORTING SWITCH and capable of dissi-
pating the full output power of the unit under test.
3. DC voltage monitor, digital voltmeter, or power supply analyzer.
4. Current sensing resistor, for current regulation measurements, four-terminal device.