Applicable Model: 8500, 8502, 8510, 8512, 8514, 8518, 8520, 8522, 8524, 8526
Q: How come my 85xx DC load does not allow me to set a higher value or at the maximum input rated limit for current, voltage, or power?
A: This happens most often when the internal maximum input protection settings are not configured to a value at or higher than the value you are trying to set to for current, voltage, and power.
To verify and configure this from the front panel, go into the menu system (shift + 0). Use the down arrow key to go into the submenu system "SYSTEM SET". Press enter and the display will first show "MAX CURRENT SET". Press enter to adjust the maximum input current for the load. This value will limit the range adjustable for current when in CC mode. It will also limit the load from exceeding this current when operating and loading from a connected DC source. Similarly, users can use the down arrow to toggle through "MAX VOLTAGE SET" and "MAX POWER SET" to configure the maximum voltage and power limit respectively.
Note: Be sure to verify the maximum input power because in all instances, settable current and voltage may also be limited by the maximum input power because if the current and voltage values are calculated to hit the power limit, user will not be able to adjust current or voltage any higher. For example, if maximum input power is set to 20 W and the source connected is 20 V, running in CC mode current adjustability will not exceed 1 A even if under "MAX CURRENT SET" the limit is set above 1 A.
To verify and configure this from the PV8500 software included with the instrument, open up the software and go into the "Config" menu by clicking the top "Config" labeled button. On the right side of the configuration window, there are several tabs for CC, CV, CW, and CR modes. Each of them has a maximum input limit setting. The value set here at the time of connecting the load with the software will be applied. For example, the default current maximum input value is 15 A. So if user try to adjust more than 15 A from the software, it will not be allowed due to this maximum input setting. Verify and/or change these values before connecting to the instrument.