8
HSF-A 1500W 010421
FIGURE 7. CONNECTIONS FOR REMOTE VOLTAGE CONTROL
3.6
REMOTE ON-OFF
When power is ON at the source, the output may be turned ON or OFF using the +RC signal if the
remote ON-OFF feature is enabled. Note that when remote ON-OFF is enabled, the RESET OUT-
PUT switch does not function. The unit can be reset using the remote ON-OFF feature or by leav-
ing the unit OFF for at least 40 seconds
Remote ON-OFF is enabled by setting DIP switch position 4 to ON and position 5 to OFF. The
+RC signal, referenced to COM (at the rack adapter I/O connector, pins 15 and 10, respectively)
then turn the unit on or off. These pins accept a logic level (3.3 to 5V “high” and 0.0 to 0.4V “low”),
or a contact closure. When +RC to COM is open using a high level logic signal, the power supply
output is cut OFF. When +RC is shorted to COM, the output returns to within specifications. Posi-
tions 4 and 5 of the DIP switch must be restored to the factory default setting (Figure 5) if remote
ON-OFF is not used. The +RC pin is not isolated from the negative DC output pin.
3.7
PROTECTION CIRCUITS
The following protection features are implemented in the power supplies: overvoltage and over-
temperature (PAR. 3.7.1), current limit/excess power (PAR. 3.7.2) and fan failure (PAR. 3.7.3).
The power supply provides a configurable visual alarm (see PAR. 3.8.1) as well as an option to
use either relay contacts or logic levels for alarm signals (see PAR. 3.8.2)
3.7.1 OVERVOLTAGE AND OVERTEMPERATURE PROTECTION
When the output voltage of the power supply increases beyond the specified values (see Table 2),
the output is cut OFF and the fan turns OFF. To restart (reset) the unit, press and release the
OUTPUT RESET switch on the front panel or use the remote on/off feature (see PAR. 3.6).The
unit may also be restarted by turning the POWER ON/OFF switch to OFF, waiting at least 40 sec-
onds, then setting the POWER switch to ON.
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 40 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 40 sec-
onds.
REMOTE VOLTAGE
CONTROL USING
EXTERNAL RESISTANCE
RA 19-4C
RA 19-4C
HSF SLOT 1
I/O 1
LOAD
J2
RV
COM
J2
I/O 1
10
12
VOLTAGE
SOURCE
LOAD
REMOTE VOLTAGE
CONTROL USING
EXTERNAL VOLTAGE
- +
- +
COM
RV
10
12
