It was released worldwide in November 2010 for Microsoft Windows, the PlayStation 3, Wii, and Xbox 360, with a separate version for Nintendo DS developed by n-Space. Aspyr later ported the game to OS X in September 2012. It is the seventh title in the Call of Duty series and the sequel to Call of Duty: World at War.
Yes, the majority of the Call of Duty games are set within the same universe, with interconnected storylines and recurring characters. However, some of the games, particularly those in the "Black Ops" and "Modern Warfare" sub-series, have their own separate continuities and story arcs.
Grounding transformers are typically used to: Provide a relatively low-impedance path to ground, thereby maintaining the system neutral at or near ground potential. Limit the magnitude of transient overvoltages when restriking ground faults occur. Provide a source of ground fault current during line-to-ground faults.
NGR Sensing Resistors are attached in parallel to the Neutral Grounding Resistor. The sensing resistor allows a protective relay which detects resistor failure in a continuous manner. Sensing Resistors are used in combination with neutral grounding resistor monitor relays.