HSF 600W 042315
9
shown in Figure 6A (factory default) To adjust voltage, first place the unit under an operating load.
Then monitor the (+) and (–) test points on the front panel with a precision voltmeter and turn the
voltage control to the desired operating value. Refer to Table 2 for the recommended Adjustment
Range of all the HSF 600W Models.
3.4.2 REMOTE VOLTAGE CONTROL
For remote voltage control, set positions 1, 2 and 7 as shown in Figure 6B. This removes control
from the front panel Vadj control and allows the output voltage to be adjusted by either an external
trimmer pot (resistance) or by an external variable voltage source connected across the rack
adapter I/O connector pin 12 (RV, Remote Voltage) and pin 10 (–COM, Common) as shown in
Figure 7. At the rack adapter I/O connector use a shielded wire 6.6 feet (2M) maximum in length,
for connection of REF (pin 2), RV (pin 12), and –COM (pin 10) to the trimmer control or external
voltage source.
NOTE: If remote voltage control is not implemented, the factory default for positions 1, 2 and 7 of
DIP switches SW1 and SW2 must be restored (Figure 6A).
FIGURE 6. DIP SWITCH SETTINGS FOR CONTROL OF OUTPUT VOLTAGE
It is possible that overvoltage protection may be triggered if the output voltage is decreased to a low
level very quickly when the power supply is at a low load condition.
RESISTANCE: Connect the external trimmer as shown in Figure 7A. Suggested value for the trim-
mer control is 5K ohms. Referring to Figure 7 (A), Resistor R is used to obtain minimum output
voltage required to ensure proper operation of the alarm relay and LED indicator; see Table 4 for
values. NOTE: Output voltage may not adjust to 0V due to residual trimmer resistance.
VOLTAGE. By adjusting an external 0 to 6V voltage source (0 to 5.5V for the 48V model), the HSF
power supply output voltage can be adjusted as specified in Table 2. To ensure proper operation of
the alarm relay and LED indicator do not adjust external voltage below minimum listed in Table 4.
Connect the voltage source across the RV and –COM pins as shown in Figure 7B.
TABLE 4. MINIMUM CONDITIONS FOR RELAY AND LED OPERATION
MODEL
HSF 12-53
HSF 15-43
HSF 24-27
HSF 28-23
HSF 48-13
Minimum HSF output voltage required for relay and
LED functioning (Volts d-c)
1
9.0
11.5 17
21.5
35
Minimum resistance of Limit resistor R (Figure 7A) in
series with 5K ohm Trimpot to ensure proper operation
of LED and relay (Ohms)
1
9.1K
9.1K
7.5K
9.1K
10K
Minimum external voltage (Figure 7B) to ensure proper
operation of LED and relay. (Volts d-c)
1
3.8
3.8
3.6
3.9
3.4
1
- If operating below minimums listed, see PAR. 3.7.2.2 to implement ±PF alarm signals to monitor power supply status.
OFF
SW1
3043032
COM 7
REF 1
RV 2
7
7
SW2
7 COM
1
ON
2
1
2
OFF
1 REF
2 RV
ON
7
7
1
2
OFF
ON
1
2
OFF
ON
USING Vadj CONTROL
FRONT PANEL VOLTAGE CONTROL
A
B
(FACTORY DEFAULT)
REMOTE VOLTAGE CONTROL
OR VOLTAGE SOURCE
USING EXTERNAL TRIMPOT
COM 7
REF 1
RV 2
2 RV
1 REF
7 COM
SW1
SW2
TAB
