Special Test Equipment; Test Equipment; Split-Bus Power Supply - GE AF-650 GP Operating Instructions Manual

10 Special Test Equipment

10.1 Test Equipment

Test tools have been developed to aid in troubleshooting these products. It is highly recommended for repair and servicing this equipment that these tools be
available to the technician. Without them, some troubleshooting procedures described in this manual cannot be carried out. Although some test points can be
found inside the frequency converter to probe for similar signals, the test tools provide a safe and sure location for making necessary measurements. Test
equipment described in this section is available from GE.
Using the test cable allows powering the frequency converter without having to charge DC bus capacitors. Main input power is required and
all devices and power supplies connected to mains are energised at rated voltage. Use extreme caution when conducting tests on a powered
frequency converter. Contact with powered components could result in electrical shock and personal injury.

10.1.1 Split-bus Power Supply

Powering the drive in the split bus mode allows dynamic testing on the drive in a safer manner.
In the split bus mode, the DC bus in each module is split into two portions. One connects to the DC bus and power card to provide low voltage power for the SMPS.
By powering only the SMPS in each module, the various logic circuits can be tested without the danger of damaging the power components.
The other provides low voltage power to the DC capacitors and the output IGBTs for test purposes. A low voltage power supply connected to the DC bus allows
testing the functionality of the output section safely.
The following procedure will be referred to throughout the dynamic test section.
Powering the Drive in Split Bus Mode
1. Ensure that AC power has been removed and that all DC capacitors are fully discharged.
2. Remove the top and bottom safety covers from each inverter module as well as the top safety cover from the rectifier module.
3. If a motor is connected to the drive, remove all output bus bars from each inverter module. Also remove the brake bus bars if the drive is equipped with
the brake option.
4. Remove the plugs from the 6-pin sockets on each module.
5. Connect the power supply cable (p/n 6KAF6H8766) to the 6-pin sockets of each module.
6. Connect a 610 – 800VDC power supply to the input end of the power supply cable.
7. Apply power to the power supply. The Keypad should light up as if the drive were powered normally.
8. Warning 24, External Fan Failure will be displayed in the Keypad. This is because the fan circuitry is not powered in this mode. This will not affect the
operation.
High Power Service Manual for Unit Sizes 6x
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