What are the definitions of OVP, OPP, OCP, SCP, OTP and BOP?


What are the definitions of OVP, OPP, OCP, SCP, OTP and BOP?

A common misunderstanding/assumption about protection standards is that they are set with the intention of protecting the whole system. This is false. These protections are only designed to protect the unit itself, not the whole system. This is because a power supply unit cannot decide how much wattage it wants to export. It simply responds to the system's needs/demands from the motherboard, graphics card, and other directly connected components.


(V Platinum 1300W)

  • OVP (Over Voltage Protection): A power supply feature which shuts down the unit, or suspends the output, when the voltage exceeds a preset level. It is generally activated when the voltage output exceeds 110% to 130%. 
  • OPP (Over Power Protection): Prevents damage resulting from excessive power output. This is usually activated when the power to connected components reaches 130% to 150%.
  • OCP (Over Current Protection): Protects against the potential dangerous effects of pushing too much current into the PSU. This can cause the unit to overload or short-circuit, potentially creating a faulty current and damaging a power supply unit or connected components such as the motherboard. It will be activated when the export current reaches 130% to 150%. 

    Ironically, this protection setting is often the main reason systems can be unstable. This is because sometimes the motherboard and the graphics card are pushed to the point that current needs set of this protection prematurely, as in the system is working properly, but the amount of current is outside the predetermined range of safety, ultimately triggering the OCP and shutting down the system.
  • SCP (Short Circuit Protection): Prevents the motherboard from burning due to high temperature output.
  • OTP (Over Temperature Protection): Shuts down the power supply when the internal temperature exceeds the maximum safe operating temperature.
  • BOP (Brown Out Protection): Prevents a power supply unit from being damaged due to a sudden drop in voltage from inconsistent electrical grids.

The power supply unit usually takes the blame for system shut downs but in fact the main reason is rather complicated and often has more than one root cause working in tandem. PSU engineers are tasked with figuring out a way to conquer these complexities and provide users a stable power supply unit that will meet power demands of the system without burning out at the same time.