Sequoia / Tahoe Series User Manual California Instruments
72 M447352-01 REV-A
LKS (Option)
Signal inputs in Auxiliary units for Clock and Lock that are used to synchronize two or more
sources; CLOCK sets the frequency, while LOCK sets the phase; logic level,
TTL-compatible; individual rear panel BNC connectors for each signal; safety isolation
SELV-rated, referenced to chassis.
Table 3-32. External Clock/Lock Interface Characteristics (Option)
3.10 Basic Initial Functional Test
CAUTION!
Work carefully when performing these tests; hazardous voltages are present on the input
and output during this test.
Refer to Figure 3-25 for the required functional test set up. Proceed as follows to perform a basic function
check of the power system:
1. Verify the correct AC line input rating on the nameplate of the Sequoia/Tahoe unit(s) and make sure
the correct three-phase line voltage is wired to the input of the chassis before applying input power.
2. Connect a suitable resistive or other type load to the output of Sequoia/Tahoe unit. The load
resistance value will depend on the voltage range you plan to check. Make sure the power resistor
has sufficient power dissipation capability - up to 15 KW for full load test on one phase of SQ0045-3
- and that the load used does not exceed the maximum power rating of the SQ0045. For three
phase configurations, this test can be performed on one phase at a time if needed.
3. Connect an oscilloscope and DMM / voltmeter to the AC source output. Set both for AC mode.
4. If the correct voltage is present, turn on the Sequoia/Tahoe unit(s) by closing the On/Off Push
Button on the front panel. For multi-chassis setup, turn on the auxiliary/follower unit first and wait for
them to cycle on, then turn on the leader unit.
5. If the Sequoia/Tahoe unit has more than one available output voltage range, go to the Configuration
- Range menu screen and select the desired voltage range. The output mode can be set from the
Configuration – Mode menu screen. Select AC mode.
6. Set the output voltage to 0 volt and close the output relay with the OUTPUT ON/OFF button. There
should be little or no output although the DMM may show a noise level, especially if the DMM is in
auto ranging mode.
7. Select the VOLTAGE field in the Dashboard screen or through Output Program – Voltage and either
use the numerical keypad to program a small voltage (20 VAC) or slew the voltage up slowly with
the rotary encoder. Observe the DMM reading. The reading should track the programmed voltage.
8. Also monitor the scope. The output should be a sinusoidal voltage waveform.
9. If the output tracks, increase the voltage till you reach 80 % of the voltage range or more. Check the
output voltage reading and waveform.
10. Select the MEASUREMENT menu screen. The output voltage, current and power will be displayed.
For three phase configurations, go to Configuration – Phase Number menu and select three phase.
This will show the voltage, current and power for all three phases. If all phases are loaded equally,
the same current and power should be visible for all three unless the voltages are not programmed
to the same level. If only one phase is loaded, current and power will only be shown for the loaded
phase.
In the unlikely event the power source does not pass the functional test, refer to the calibration procedure
in the manual.
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