Where a neutral conductor is used also to connect equipment enclosures to earth, care must be taken that the neutral conductor never rises to a high voltage with respect to local ground. The terms “ground” and “earth” are used synonymously here. Ground” is more common in North American Multiple earthed neutral system pdf, and “earth” is more common in British English.
Under normal conditions, a grounding conductor does not carry current. Adding new grounds requires a qualified electrician with information particular to a power company distribution region. That is for simple single panel installations, for multiple panels the situation is more complex. In the electrical trade, the conductor of a 2-wire circuit connected to the supply neutral point and earth ground is referred to as the “neutral”. Canadian electrical code only define neutral as the grounded, not the polyphase common connection. Neutral conductors are usually insulated for the same voltage as the line conductors, with interesting exceptions.
Other arrangements of polyphase transformers may result in no neutral point, and no neutral conductors. The letter symbols are common in countries using IEC standards, but North American practices rarely refer to the IEC symbols. The differences are that the conductors may be separate over their entire run from equipment to earth ground, or may be combined over all or part of their length. Different systems are used to minimize the voltage difference between neutral and local earth ground. Current flowing in a grounding conductor will produce a voltage drop along the conductor, and grounding systems seek to ensure this voltage does not reach unsafe levels. Normal circuit currents flow only in the neutral, and the protective earth conductor bonds all equipment cases to earth to intercept any leakage current due to insulation failure. The neutral conductor is connected to earth at the building point of supply, but no common path to ground exists for circuit current and the protective conductor.