HSF(A) 600W 040215
13
3.6.4 UNDERVOLTAGE
If power supply output voltage either falls within 40 to 80% of the rated output voltage value, or is
programmed below the minimum values listed in Table 5, an alarm occurs if the internal relay
alarm (factory default, see PAR. 3.7.2.1) is enabled. To restart (reset) the unit, press and release
the OUTPUT RESET switch on the front panel or, if the remote on/off feature is in use (see PAR.
3.5), open the connection between the ±RC pins and then reconnect the pins. The unit may also
be restarted by turning the POWER ON/OFF switch to OFF, waiting 40 seconds, then setting the
POWER switch to ON. To enable the alarm function when operating below the minimum values
listed in Table 5, refer to PAR. 3.7.2.2 to configure the optically-coupled alarm.
3.7
ALARM SETTINGS
3.7.1 VISUAL ALARM.
When the unit is connected in a parallel configuration, the front panel VDC ON/ALARM indicator is
normally configured to light red if the respective power supply output voltage is lost or if the
POWER switch is set to OFF. This is enabled when DIP switch 1, position 8 is set to ON. This can
be useful to indicate the loss of output voltage from one parallel-connected power supply that may
not be readily apparent. For the visual alarm to function properly the minimums specified in Table 4
must be observed.
FIGURE 9. DIP SWITCH SETTINGS FOR RED ALARM INDICATOR ENABLE/DISABLE
If desired, the red alarm indication of the VDC ON/ALARM indicator can be disabled by setting
DIP switch 1 position 8 to OFF.
3.7.2 ALARM SIGNALS.
Either of two options are available for signalling alarms: isolated relay contacts (factory default,
PAR. 3.7.2.1) or logic level alarm signals ±PF (PAR. 3.7.2.2). The ±PF logic level alarm option
must be used if the power supply is intended to operate below the minimum voltages listed in
Table 5.
3.7.2.1 INTERNAL ISOLATED RELAY ALARM
The first option, the factory default setting, uses an isolated internal relay offering normally closed
(NC) and normally open (NO) contacts referenced to an isolated common (AL COM). These con-
tacts may be used to configure “close on failure” or “open on failure” alarm circuits. (Refer to the
Series RA 19-4C Manual for alarm configurations for multiple HSF (A, AM) power supplies.) Set-
ting position 5 of the DIP switches as shown in Figure 10A selects this option. The NC (pin 6 of the
rack adapter I/O connector) and NO (pin 7) signals are referenced to Alarm common (pin 14).
3.7.2.2 OPTICALLY-COUPLED LOGICAL ALARM
The second option uses optically-coupled logic level alarm signals, +PF (pin 5 of the rack adapter
I/O connector) and -PF (pin 13), provided directly from the internal power supply that is the heart
of the HSF (A, AM) power supply. The optically-coupled logic alarm is selected by setting position
5 of the DIP switches as shown in Figure 10B. This option functions even with output voltage
adjusted below the minimum voltages specified in Table 5.
3043783
SW1
SW2
8
OFF
ON
OFF
ON
(FACTORY DEFAULT)
RED ALARM INDICATOR ENABLED
A
RED ALARM INDICATOR DISABLED
B
8
SW1
SW2
OFF
ON
ON
OFF
8 ALARM LED ENABLE
8 ALARM LED ENABLE
TAB
