Similar to the OCP, the OPP is one of the protective circuits built into the power supply. OPP stands for Over Power Protection. If a power supply is operated at an excessive power level, the OPP protects the power supply against a technical breakdown.

Overclocking Key

The Overclocking Key is a concept developed by be quiet! to connect several 12V rails. The key is used for the DARK POWER PRO series since generation P8. Several 12V rails can be connected into a high-powered 12V rail. This is particularly beneficial for high-performance computer systems that work at the edge of their performance envelope (overclocking) and for which standard power supply via divided 12V rails is insufficient.


Over Voltage Protection protects the PC against overly high voltages. To prevent damages to the PC, the power supply turns off when an over voltage is present.


This important protective circuit stands for Over Temperature Protection. Heat is created within the power supply during control actions. It the interior of the power supply becomes overheated, the OTP protects the electronics against damages.

On-site replacement service

As the name indicates, on-site replacement service is a type of service. It involves the replacement of defective devices without the need to travel to a specialised dealer. If a device is defective during the guarantee period, then a technician travels to your residence or office to replace the defective device.


The OCP is one of the power supply's protective functions. It stands for Over Current Protection. If a voltage rail draws more current from a power supply than the power supply specification permits, then the OCP intervenes and switches off the power supply.