KEPCO BOP-GL 1KW Operator Manual Firmware Ver.3.05 and higher - Manual (Page 70)

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BOP-1K-GL 022814
To ensure these settings are restored after a power cycle send MEM:UPD LIM and tag the
unit with the new power-up configuration. To restore factory default limits and undo the limits
saved by MEM:UPD LIM command, perform a reset power-up (see PAR. 3.3.2.1).
3.3.6 MAXIMUM/MINIMUM PROTECTION LIMITS (SOFTWARE-CONTROLLED)
The ± protection limits are software limits that establish the maximum and minimum (maximum
negative) allowable levels of output voltage in current mode and current in voltage mode. The
default protection limits are 1% above E
Omax
or 1% above I
Omax
.
CAUTION: WHEN WORKING WITH ACTIVE LOADS, ALWAYS ADJUST THE BOP PRO-
TECTION LIMITS TO BE ABOVE THE MAXIMUM VALUES OF VOLTAGE OR CURRENT
EXPECTED FROM THE LOAD. FOR EXAMPLE, WHEN THE BOP IS OPERATING IN VOLT-
AGE MODE SINKING ENERGY FROM A CONSTANT CURRENT TYPE LOAD, SET THE
CURRENT PROTECTION LIMITS OF THE BOP ABOVE THE MAXIMUM CURRENT
EXPECTED FROM THE LOAD.
The protect channel limits are +V (voltage) Protect max, –V Protect min, +C (current) Protect
Max and –C Protect min (see Table 3-2); these prevent the unit from delivering voltage or cur-
rent that exceed these settings. In voltage mode the current protect channel is clamped to the
limit value; in current mode the voltage protect channel is clamped to the limit value. Adjustment
range is between a minimum (box) value (see Figure 1-3) and 1% above the nominal (rated)
value.
3.3.7 DETERMINING HOW THE UNIT RESPONDS WHEN OUTPUT IS OFF (LOAD TYPE)
The BOP supports three Load Type selections (see Table 3-3) which determine how the power
supply responds when the output is off: ACTIVE, RESISTIVE and BATTERY. These selections
are designed to provide proper operation with different load types. It is important to note that the
Load Type selection does not affect the settings of the power supply for ON state; it only affects
the main internal reference level and the protection levels during the OFF state. Load type is
selected by performing a Reset Power-up (see PAR. 3.3.2.1) or by using the digital
OUTP:MODE command (see PAR. B.17).
For inductive loads, and especially superconducting magnet type
loads, the inherent offset of the BOP in the OFF state may generate sig-
nificant current in the circuit. A properly rated switch in parallel with a
resistor must be connected between the power supply and the load.
The switch must be open and voltage and current measurements at the
output must read 0V, 0A before removing or installing connections
between BOP and load.
ACTIVE. Active mode (default setting) is necessary for the power supply to function properly
and safely with inductive loads and constant-current-type active electronic loads. Active mode
can also be used with resistive loads. Table 3-3 indicates how the power supply responds to a
command to go from Output ON to OFF. When the output is disabled, the unit is set to voltage
WARNING