AMETEK PLA-PLW - Manual (Page 63)

PROTECTION
OV PROTECTION
UC
PROTECTION
OV DELAY UC DELAY
UV PROTECTION OP PROTECTION
UV DELAY OP DELAY
OC PROTECTION UP PROTECTION
OC DELAY UP DELAY
AMREL eLOAD provides programmable OVP/OCP/OPP and UVP/UCP/UPP over-limit and under-limit protection
capabilities. The user can program all of the protection values and delay times. Protection will be activated once the
protection mode has been tripped and then shut down the eLOAD input. The protection delay setting provides a
programmed delay time to accommodate short duration surges without inadvertently shutting the input off.
Protection Sub-Menu Navigation: Press the "Menu/Local" key then turn the 43 encoder to select the PROTECTION
function then the "ENTER" key. Turn the 43 encoder to select the appropriate protection or delay function by pressing
the "ENTER key to display the current value. Press the "ENTER" key to edit or enter the new value then press the
“ENTER” key to confirm entry. Press the “CLEAR” key to exit from the PROTECTION MODE sub-menu.
V-ON (Under Voltage Lockout): To prevent the eLOAD from operating under unstable conditions such as voltages
below the minimum operating voltage, the V-On Protection feature can be utilized. The V-On protection will force the
input to remain off until the V-On voltage threshold is exceeded, the purpose is to ensure sufficient voltage is delivered to
the eLOAD for normal operation. When operating under strict turn-on sequences, such as sending power via a power
supply into an eLOAD with the input already turned on, current overshoot, bounce or ringing may occur. As a
recommendation for improved performance without changing the turn-on sequence, the V-On threshold can be increased
to a voltage closer to the application’s operating voltage and the V-On detection mode changed to “Continuous”. By
making the necessary adjustments, both the DUT and eLOAD can operate under stable conditions to avoid irregular
results. To achieve best results, the V-On Voltage should be set to a level higher than the stabilizing voltage of the power
supply or DUT, and higher than the eLOAD’s minimum operating voltage. Please refer to “Protection Feature” in section
one for a detailed explanation of the different V-On modes.
Fault Signal: Each time a protection fault triggers, the Fault pin becomes active TTL high. When this occurs, the
appropriate bits in the status register are set and the fault signal is latched. The status bits will remain set until the
electronic load is reset via the GPIB or RS232 (*RST command) or at the front panel (CLEAR key). The condition that
caused the protection feature to trip must be corrected or the load will turn off again.
Note: Because the protection is done through software, the response time for the delay trip time must be set to at least
50ms for each protection feature. Otherwise the load may not reset correctly if the trip delay time is too short.
MAX/MIN SETTING FUNCTION
To change the values, press the "Menu/Local" key press Enter, then use the 43 keys to select the Max/Min Limit
function then the "ENTER" key. Use 43 keys to select the appropriate Min/Max setting by pressing the "ENTER key.
The LCD will display the current value, press the "ENTER" key to enter a new value and press the “ENTER” key to
confirm entry. Press “CLEAR” key to escape the Max/Min Setting MODE.
The following are special eLOAD MAX/MIN settings that can be programmed to prevent erroneous value entry for
specific applications or special power sources that are sensitive to inappropriate operating values.
MAX VOLTAGE - Max V
MIN VOLTAGE - 0.000V
MAX CURRENT - Max A
MIN CURRENT - 0.0000 A
MAX RESISTANCE - Max OHM
MIN RESISTANCE - 0.00 OHM
MAX POWER - Max W
MIN POWER - 0.00 W
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