To set these protection values, use the following keystrokes:
Keys
Display
Shift
+
Menu
:CONFIG
▽
:SYSTEM SET
Enter
Select between:
:MAX CURRENT SET
:MAX POWER SET
:MAX VOLTAGE SET
using the
△
and
▽
arrow keys, then press
Enter
. Enter the desired value,
then press
Enter
to accept it.
Esc
Esc
Exit from the menu.
Example: Suppose you are measuring current vs. voltage characteristics of a 1 watt resistor. You
could set the maximum allowed power to 1.1 watts to test the resistor's rating, yet not go over the
maximum rating by more than 10% to ensure you don't destroy the resistor. If you tried to use the
P-
set
key to set the power to more than 1.1 W, the instrument will limit the set value to 1.1 W.
Over Voltage protection
If input voltage exceeds the voltage limit set by the user, the DC load will turn the input OFF and the
buzzer will sound. The display will show
OVER VOLTAGE.
The maximum voltage limit value is equal to
the maximum rated voltage for each model. For the over voltage protection state to be activated, the voltage
level presented to the load terminal must exceed the limit set value by approximately 5%.
Over Current protection
When operating in CR, CC or CW mode, the load current will be limited by a current limit value set
by the user. The maximum current limit value is equal to the maximum rated current for each model.
Once the maximum current limit is reached, the DC Load will enter the over current protection state
and the current will be limited to the set value. (The input will not turn off). If the DC load previously
operated CR or CW mode, the DC load will automatically revert to CC mode and the VFD display
will indicate CC. When the DC load operates in a combined CV / transition mode or CV / List mode,
the buzzer will sound if the input current exceeds the current limit and the display will show a
flashing current value.
Over Power protection
If the input power exceeds the power limit in the normal operation mode, the DC load
will enter the over power
protection state. The display will show CW.
If the input power exceeds the limit when in transition mode or list mode, the buzzer will sound and the
display will flash the current value and voltage value.
Reverse voltage protection
This feature protects the load module in case the DC input terminals are connected to a power source with
reversed polarity. If a reverse voltage condition is detected, the buzzer will sound and
REVERSE VOLTAGE
will be displayed on screen.
8500 DC Load Series
Version: February 4, 2009
Page 41 of 76
