KEPCO EL Series Electronic Load Operator Manual P/N 243-1295 Firmware Version 4.00 to 4.xx - Manual (Page 63)

SERIES EL 071414
3-27/(3-28 Blank)
3.17 ANALOG PROGRAMMING
The Analog input applied to either ±REF IN terminals (hazardous) or ANALOG CONTROL pins
2 and 7 (isolated SELV), is summed with the digital setpoint value. ±REF IN terminals are
enabled at the factory (default); refer to PAR. B.96 to change the external programming source.
Refer to PAR. 2.6.5 for analog input signal details. A positive Analog input voltage increases the
digitally determined setpoint, a negative voltage decreases the digitally determined setpoint.
Because the analog input signal is summed with the digital setpoint, it must produce a result that
is either 0 or positive, since the load can not control current in the negative direction.
For example, for the EL 5K-400-400 in CI Mode, if the digital setpoint is zero, a 0 to10V signal
applied to the Analog input adjusts the controlled parameter (current) from 0 to full scale (400A).
However, if the digital setpoint is set to 200A, ±5V applied to the Analog input allows current
from 0A (-5V) to 400A (+5V).
For Master/Slave configurations, the Analog input programming signal must be simultaneously
applied to all parallel-connected units.
3.18 OPERATOR MAINTENANCE
No scheduled maintenance is required, other than to keep the high current connections tight
and to ensure all airways are clear of obstructions that could cause the load to overheat during
operation at higher power. Calibration Verification should be performed yearly or as required.
The exterior of the load should be cleaned periodically, as is necessary, using a soft cloth damp-
ened with a mild, non-abrasive, water-soluble detergent, and then rinsed with a water-damp-
ened soft cloth.