B&K Precision 8500-8526 - Manual - Manual (Page 43)

Shift + A
Shift + B
Shift + Short
Shift + Tran
Shift + Trigger
On/Off
To remove the password, enter the menu CONFIG:KEY LOCK SET and do not press any number
keys, then press Enter.
Protection features
To protect external hardware when using the DC Load, you can set the maximum allowed values for
current, voltage, and power. These settings will override any settings subsequently made from the
front panel using the I-set, V-set, P-set, or R-set keys.
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
8500 DC Load Series Version: 030614 Page 43 of 77