3 DC Power Supply Operation  
Protection Functions
78 U3606A User’s and Service Guide
Protection Functions
Overvoltage protection (OVP)
In constant current mode, the U3606A regulates the output current at the 
selected value, while the voltage varies as required by the load. The 
overvoltage protection protects against overvoltage conditions on the 
output. If the load attempts to draw more voltage than required, such that 
it exceeds the programmed protection value, the overvoltage protection 
circuit will protect the load by disabling the output.
The following steps shows you how to set the OVP trip level, how to check 
OVP operation, and how to clear the OVP condition.
Setting the OVP trip level
1 The OVP trip level can be programmed when the output is enabled 
(OUT) or disabled (SBY). Ensure that the U3606A is operating in 
constant current mode. (The CC annunciator is illuminated.) Press  
Shift > Protect to enter the OVP edit menu.
2 Press   or   to select which digit position to be changed.
3 Press   or   to increase or decrease the value. The OVP value is set 
to the maximum protection limits by default. 
• 33.000 V when range S1 is selected, and
• 8.8000 V when range S2 is selected.
4 Press  Shift > Save or Voltage (Protect) to save the changes. “donE” will be 
briefly displayed in the upper secondary display. The display will then 
return to normal.
5 Alternatively, press Shift > Exit or Shift > Protect to exit the edit mode 
without saving.