6 protection circuits, 1 overvoltage and overtemperature protection, 2 overcurrent setting and protection – KEPCO HSF 300W Series (no suffix) Operator Manuals User Manual

Page 11: 3 fan failure, Ar 3.6.1) fault, R. 3.6.2)

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HSF 300W 050113

9

“high” and 0.0 to 0.4V “low”), or a contact closure. When the ±RC pins are open, using either a

mechanical switch or a high level logic signal, the HSF 300W output is cut OFF. When the ±RC

pins are shorted, the output returns to within specifications. At low level logic, the maximum

source current is 1.6mA and at high level the sink current is 1.0mA. Positions 3 and 4 of both DIP

switches must be restored to the factory default setting (Figure 8A) if remote ON-OFF is not used.

The ±RC pins are isolated from DC output pins and a-c input terminals.

FIGURE 8. DIP SWITCH SETTINGS FOR USING RESET BUTTON OR REMOTE ON-OFF

3.6

PROTECTION CIRCUITS

The following protection features are implemented in the HSF 300W Series: overvoltage and

overtemperature (PAR. 3.6.1), overcurrent (PAR. 3.6.2), fan failure (PAR. 3.6.3), and undervolt-

age (PAR. 3.6.4). The HSF 300W Series provides a configurable visual alarm (see PAR. 3.7.1) as

well as an option to use either relay contacts or logic levels for alarm signals (see PAR. 3.7.2)

3.6.1 OVERVOLTAGE AND OVERTEMPERATURE PROTECTION

When the output voltage of the HSF 300W 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, if the remote on/off feature is in use

(see PAR. 3.5), open 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.

When the internal temperature of the HSF 300W Power Supply increases beyond allowable limit,

the output is cut OFF and the fans turn OFF. The restart cycle (Power ON) should not begin until

the temperature returns to within specifications. To restart (reset) the unit, set the POWER ON/

OFF switch to OFF, wait until unit cools, 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 seconds.

3.6.2 OVERCURRENT SETTING AND PROTECTION

The output characteristic of the power supply is a square type, and the unit is set to produce an

alarm (see PAR. 3.7.2) and shut down if output current exceeds specifications (see Table 2) for

more than 30 seconds. After the cause of overcurrent is removed, the power supply output is auto-

matically restored.and shut down if output current exceeds specifications (see Table 2) for more

than 30 seconds. Once unit shuts down, to recover either: a) press and release the front panel

OUTPUT RESET switch, or b) open and close connection across ±RC terminals, or c) remove a-c

input power (set POWER switch to OFF), wait 40 seconds, then restore a-c input power.

3.6.3 FAN FAILURE

A cutoff of the fan supply voltage or a decrease in fan speed causes the output to shut down and the

fans to turn OFF. Fan failure and all the other protection circuit operations produce an alarm (see

PAR. 3.7.2). 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. 3.5), open the connection between the

±RC pins and then reconnect the pins. The unit may also be restarted by turning the POWER ON/

3042877

3

3 +RC

+RC 3

3

SW1

-RC 4

4

SW2

4

4 -RC

OFF

ON

OFF

ON

(FACTORY DEFAULT)

USE FRONT PANEL

RESET BUTTON

A

B

(LOGICAL LEVEL OR

MECHANICAL SWITCH)

USE REMOTE ON-OFF

3

3

SW2

SW1

4

4

ON

OFF

OFF

ON

3 +RC
4 -RC

+RC 3

-RC 4

TAB

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