KEPCO HSF 1500W Series (all models) Operator Manuals - Manual (Page 12)

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HSF 1500W 022613
When the internal temperature of the power supply increases beyond safe values, the output is
cut OFF and the fans turn OFF. The restart cycle (Power ON) should not begin until the tempera-
ture returns to within specifications. To restart (reset) the unit, set the POWER ON/OFF switch to
OFF, wait 30 seconds, then set the POWER switch to ON. The power supply cannot be reset
using the remote ON-OFF feature unless the power supply remains shut down for at least 30 sec-
onds.
3.7.2 OVERCURRENT/CURRENT LIMIT SETTING AND PROTECTION
From 170 to 265V a-c input, the output characteristic of the power supply is a square type, and the
unit is set to produce an alarm (see PAR. 3.8.2) and shut down if output current exceeds specifica-
tions (see Table 2) for more than 30 seconds and undervoltage detection is present (see PAR.
3.7.4). From 85 to 170V a-c input, operation (including alarm signals) is intermittent when current
limit condition occurs. To restart (reset) the unit, remove AC input power, wait 30 seconds, then
reconnect AC input power, or open the RC terminals and then reclose the terminals.
3.7.3 FAN FAILURE
A cutoff of the fan supply voltage causes the output to shut down and the fans to turn OFF. Fan fail-
ure and all the other protection circuit operations produce an alarm (see PAR. 3.8.2). 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. 3.6), 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 30 seconds, then setting the POWER switch to ON. If fan rotation is out of specification
the power supply will not recover.
3.7.4 UNDERVOLTAGE
If the output voltage of the power supply falls below 60 percent of the rated voltage for 30 seconds (5V
for the 36V model) while overcurrent is detected,
the unit turns off and an alarm occurs (either from
the internal relay or optically-coupled alarm circuit, see PAR. 3.8.2). 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. 3.6), 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 30 seconds,
then setting the POWER switch to ON.
3.8 ALARM SETTINGS
3.8.1 VISUAL ALARM.
When the unit is connected in a parallel configuration, the front panel VDC ON/ALARM indicator
can be 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 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. The visual alarm is normally disabled: DIP switch SW1, position 8 set to OFF
(factory default).
3.8.2 ALARM SIGNALS.
Either of two options are available for signalling alarms: isolated relay contacts (factory default,
PAR. 3.8.2.1) or logic level alarm signals ±PF (PAR. 3.8.2.2).
3.8.2.1 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 power supplies.) Setting posi-
tions 5 and 6 of the DIP switches as shown in Figure 9A 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).