KEPCO BHK-MG 40W (Half Rack) Series - Manual (Page 26)

1-10
BHK-1/2-MG (OPR) 121313
1.4.4 OVERVOLTAGE/OVERCURRENT PROTECTION
Overvoltage and Overcurrent protection values can be individually programmed. The range for
overvoltage and overcurrent values are 0 to 1.1 x E
O
max, 0 to 1.1 x I
O
max. If the output volt-
age/current is maintained at or above the overvoltage/overcurrent protection value for more
than 9ms, the protection circuit cuts the pass element off, discharges the output capacitor, trips
the POWER circuit breaker to OFF and sends a flag on a dedicated line (status port connector).
The default values are 1.1 x E
O
max for overvoltage protection, and 1.1 x I
O
max for overcurrent
protection. Refer to PAR. 3.2.10 for more information.
1.4.5 USER-DEFINED VOLTAGE/CURRENT LIMITS
The BHK-MG 40W Power Supply can be programmed not to exceed user-defined values that
can be lower than the maximum values. For example, the BHK 500-80MG, which has maximum
output values of 500V d-c, 0.08A d-c, can be limited to 100V d-c, 0.04A d-c for working with cir-
cuitry that might be damaged by higher levels. Once the limits are set, the power supply
becomes, in effect a 100V d-c, 0.04A d-c supply and values exceeding the limit values will not
be accepted. Refer to PAR. 3.2.11 for more information.
1.4.6 NONVOLATILE STORAGE OF PROGRAMMED SEQUENCES OR ACTIVE SETTINGS
The BHK-MG 40W Power Supply contains 40 memory locations that can be used either to pre-
program a sequence of output values or to store active settings. For programming sequences
each memory location accommodates six parameters: output voltage, output current, overvolt-
age, overcurrent, time (how long the parameters are in effect) and the next address in the
sequence. Values are stored in the nonvolatile memory, and are retained when the unit is turned
off. Refer to PAR. 3.2.15 for more information.
The same 40 memory locations are also available to save the active programmed settings (volt-
age, current, overvoltage, overcurrent). The saved setting can be recalled by specifying the
memory location. Refer to PAR’s. 3.2.12 and 3.2.13 for more information.
1.4.7 CURRENT MEASUREMENT SCALE
Measurement of a decreasing output current of the power supply that falls below 8.98% ±0.1%
of the rated value is automatically measured with increased resolution/accuracy by a factor of
10 until the current rises above 9.69% ±0.1% of rated value.
1.4.8 FAST MODE/SLOW MODE SELECTION
BHK-MG Series Power Supplies can be configured by external strapping for either slow mode
operation with the internal output capacitor connected to the output, or fast mode operation with
the internal output capacitor disconnected from the output. The slow mode (default state) is rec-
ommended for voltage stabilization because of its low output noise and low recovery amplitude
to a dynamically changing load. The fast mode offers a faster response to step or dynamic pro-
gramming of the output voltage (in voltage mode), when the power supply is used as a power
amplifier. Fast mode is also recommended for current stabilization because of its fast response
to a dynamically changing load. Refer to PAR. 3.9.1 for more information.
1.4.9 BUILT-IN PROTECTION
BHK-MG Series Power Supplies provide built-in protection against the following:
a. Overtemperature of the pass element. Heatsink temperature is monitored. If an overtem-
perature condition is maintained for more than 2.5ms, the following actions are initiated: the
pass element is cut off, the output capacitor is discharged, and the unit is turned off by trip-