KEPCO BOP-GL 1KW Operator Manual Firmware Ver.3.05 and higher - Manual (Page 79)

BOP-1K-GL 022814
3-17
saved settings upon power up: output set to voltage (gain) mode of operation with gain set to
2.9.
The gain in voltage mode is G
V
= V
SET
/10 where V
SET
is the desired full scale voltage (in Volts)
entered at the front panel.
The gain in current mode is G
A
= I
SET
/10 where I
SET
is the desired full scale current (in
Amperes) entered at the front panel.
NOTE: If the system limits have been modified (PAR. 3.3.5), the output of the power supply will
never exceed the modified system limits.
3.4.2 EXTERNAL PROTECTION LIMITS
External protection limits are established upon power-up by switches S3-3 and S3-4. Once the
unit is powered up, the signals at the analog I/O port and the digital commands can be used to
control the protection limits. Refer to Table 2-2 and PAR 3.3.11 for details. The following para-
graphs explain the operation of the analog signals assuming that they have been enabled.
Only two of the four LIM_EXT signals are active at a time, affecting the complementary protect
channel: ±current protect limit for voltage mode and ±voltage protect limit for current mode. A
voltage between +1V and +10V at the following pins (referenced to Ground, pin 12) will control
the corresponding protection parameter between 10% of the nominal value (see Figure 1-3) and
the corresponding positive or negative nominal full scale value.
• –I_LIM_EXT (pin 5) - This +1V to +10V analog signal sets the negative current protect
limit from 10% of the nominal value to –full scale current. +10V corresponds to rated
minimum (maximum negative) current (e.g., for BOP 36-28GL, +10V sets negative cur-
rent limit to –28A).
• –V_LIM_EXT (pin 6) - This +1V to +10V analog signal sets the negative voltage protect
limit from 10% of the nominal value to –full scale voltage. +10V corresponds to rated
minimum (maximum negative) voltage (e.g., for BOP 36-28GL, +10V sets negative volt-
age limit to –36V).
• +I_LIM_EXT (pin 13) - This +1V to +10V analog signal sets the positive current protect
limit from 10% of the nominal value to full scale current. +10V corresponds to rated max-
imum current (e.g., for BOP 36-28GL, +10V sets positive current limit to +28A).
• +V_LIM_EXT (pin 14) - This +1V to +10V analog signal sets the positive voltage protect
limit from 10% of the nominal value to full scale voltage. +10V corresponds to rated max-
imum voltage (e.g., for BOP 36-28GL, +10V sets positive voltage limit to +36V).
The maximum frequency of an a-c signal used for the external protection limit must be at least
10 times lower that the sampling rate of the external signal (10Hz), resulting in a bandwidth of
1Hz.
The external programming circuit must be able to sink 0.15mA maximum provided by the BOP.
When the input is an open circuit, the corresponding input signal automatically goes to 20%
above the nominal protection limit, but internally the protection value is clamped to 1.01 of nom-
inal.