TDK-Lambda 203, Operator'S Manual, Page: 32 / 60

CONTROLS, INDICATORS, CONNECTORS
83489011 Rev A
5-8
opened, disconnecting AC power from the HV circuitry. The INTERLOCK OPEN LED
indication is reset automatically when the interlock circuit is closed (LED extinguished),
but before power can be generated the fault condition must be reset by pushing the HV
OFF push-button.
5.10.5.5 BIAS FAULT (Normally OFF)
When illuminated indicates the internal DC control voltage is low, or out of range.
5.10.5.6 FAN FAIL (Normally OFF)
Indicates failure of the auxiliary cooling fan. The power supply should be removed for
service if this indicator is illuminated.
5.11 VIEW SET push button (Ref 10)
The view set push button changes the reading on the digital voltage display from the
power supply output voltage, to the programmed voltage set on the local voltage set po-
tentiometer. After pushing this button the set voltage is displayed for approximately 3
seconds.
5.12 CURRENT BAR GRAPH (Ref 11)
The current bar graph is a 'quick view' analog percentage indication of the current
measured at the power supply output. Bar graph is active in local and remote modes.
5.13 AC POWER (Ref 12)
The front panel POWER switch controls the main input power to the unit. When closed,
AC power is applied to the control logic, and if no faults are present the AC input contac-
tor will also close. The POWER switch only controls a low voltage signal, and is not di-
rectly connected to the main AC line. This low voltage control signal is wired in series
with two terminals on the rear panel. (4 position barrier strip) marked as
INTERLOCK/POWER ON (see Figure 5-3).
The INTERLOCK/POWER ON terminals at the rear of the unit must be jumpered or
wired to a remote switch or contactor. Both the remote contacts and the front panel
switch must be closed for the unit to turn on.
Once the unit is turned on using the front panel POWER switch, the internal control logic
begins a complete check of all operational circuits. The check includes all functions dis-
played on the front panel LED indicator lights. The check sequence begins with a tests
of all the lights by switching them all on for about one second to let the operator know
that all the LED's and the associated drivers are working, and that the power is applied
to the logic circuit and the internal self checks are underway.
Within 4 to 6 seconds after the POWER switch is closed and the self check sequence
commenced, all the tests are finished and the AC contactor automatically closes (a loud
‘thunk’ will be heard) applying AC power to the main power circuits, placing the power
supply in the READY state (FAULT LED is not illuminated). When READY the power
supply is considered to be armed and could be generating high voltage.
5.14 FRONT PANEL LAYOUT (S Model)
The 303S series power supply is equipped with a partially instrumented front panel fea-
turing comprehensive status LEDs, and a power on switch. The 303S can only be oper-
ated remotely via the control connector located on the rear panel (see Section 7.2).