KEPCO BOP-GL 1KW, Руководство оператора

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BOP-1K-GL 111315
3-19
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 3.3.10 for details. External protection
limits can also be configured remotely by sending either CURR:MODE:PROT EXT (see PAR.
B.31) or VOLT:MODE:PROT EXT (see PAR. B.98). The following paragraphs explain the opera-
tion 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 pro-
tect channel: ±current protect limit for voltage mode and ±voltage protect limit for current mode.
A voltage b1V and +10V at the following pins (referenced to Ground, pin 12) will con-
trol 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.
3.4.2.1 USING LESSER OF DIGITAL VS. ANALOG (EXTERNAL) LIMITS
The BOP provides the ability to automatically choose the lesser absolute value between the
external limits (applied to Analog I/O port pins 5, 6, 13 and 14) and the limits established by a
digital command. This feature is accessible through digital control and can be restored upon
power-up using a saved location.
For example, with a BOP 50-20GL, the maximum limit value in current mode can be set to 20V
using the digital interface, but the limits can be controlled by the analog limit signals applied to
pins 6 and 14 of the analog I/O port. However, if the signals at pins 6 or 14 exceed 4V (10V = full
scale or 50V, 4V is 2/5 of full scale = 20V), the digital limit will take effect and prevent the limit
from exceeding 20V. To implement this send the following commands: