AMETEK CTS 3.0 - Manual (Page 162)

Compliance Test System 3.0 User Manual
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19.4 Advanced Troubleshooting
If it is suspected that the AC sensor circuit board inside the PACS unit is defective it will be
necessary to remove the top cover of the unit and perform some basic tests to determine if the
circuit is functioning properly. See Figure 33 for location.
CAUTION: VOLTAGES UP TO 312 VAC ARE PRESENT IN CERTAIN SECTIONS OF THIS POWER
EQUIPMENT.
WARNING: THIS EQUIPMENT CONTAINS POTENTIALLY LETHAL VOLTAGES. DEATH ON
CONTACT MAY RESULT IF PERSONNEL FAIL TO OBSERVE SAFETY PRECAUTIONS. DO NOT
TOUCH ELECTRONIC CIRCUITS WHEN POWER IS APPLIED
19.4.1 Switch Off Unit, Disconnect High Voltage
Switch off the PACS unit with the front panel power on/off switch. Also disconnect or remove any
AC voltage applied to the rear connection terminals TB3 and TB4.
19.4.2 Removing Top Cover
Remove the screws securing the top cover and remove the top cover.
19.4.3 Initial Inspection
Perform a visual inspection of the unit and ensure all the connectors are properly mated and there
are no loose or broken wires. Check the interface cable going from the AC sensor assembly 5004-
700 to the front and rear panels.
19.4.4 Power-On Troubleshooting - DC Supplies
WARNING: Do not touch any parts inside the unit during these tests as they will
be live and dangerous. Always wear safety glasses.
1. Connect a DMM common test lead to TP1 on the 5004-700 AC sensor assembly. TP1 is the
circuit common for all DC supplies and test signals. Connect the other DMM lead to the
cathode of diode CR4.
2. Switch on the PACS unit with the front panel switch.
3. Verify the DC voltage at CR4-cathode is +15V.
4. Connect the other DMM lead to the anode of diode CR5.
5. Verify the DC voltage is -15V.
6. If either of these voltages are not as specified, the board will not function properly and will need
to be serviced.