Is the appliance connected to zero or protective ground? The difference between protective grounding and protection zero

If the power supply and distribution of the power supply is directly connected to the neutral point of the three windings on the low-voltage side of the distribution transformer, and the three-phase four-wire power supply and distribution of the power supply and distribution line is connected, its power supply and distribution is zero. When the line is densely and multi-point repeatedly grounded along the main line of power supply and distribution and the 220V single-phase line, it is of course more effective and reliable for the user to protect the zero. The connection method and the selection of the wires are as follows: the contact point is connected to the zero line of the power supply and distribution in front of the user's metering energy meter, and the wire for protecting the zero line (using the yellow and the edge two-color line) is either the total power source or the user. The safe current carrying capacity of the protection connection zero line of each line <back> road should match the total circuit breaker <leakage circuit breaker> and the trip current value of each line <back> circuit breaker to ensure safety. The working principle of protection and zero connection is as follows: when the insulation inside the user's power receiving device is damaged, the phase line is in direct contact with its metal outer casing. Because the metal outer casing of the power receiving device is actually connected to the protective connection line, the pole is generated. The large short-circuit current, the circuit breaker (leakage circuit breaker) that matches the safe current-carrying trip current value of the line conductor, is instantaneously tripped to ensure safety. If the user uses his own grounding grid for grounding protection, even if the grounding resistance of the new installation is suitable, but the small users do not have a full-time electrician for maintenance, it is inevitable that there will be safety hazards due to long-term disrepair.

All electrical appliances of the household appliances are protected grounding. (PN) example: washing machines, refrigerators, air conditioners, heaters, desktop computers ,, ironing machine, and so on.

The main difference between the ground and the protection of ground zero protection:

1. Protection principle Different protection grounding is to limit the ground voltage after leakage of equipment so that it does not exceed the safety range. In the power supply system, in addition to limiting the protective ground outside the ground voltage, in some cases, also cause the effect of the grid protective devices; protective zero is zero by connection lines (10) form a single phase short-circuit the drain apparatus, causes the line protective devices, and a cutting device power failure. Further, the protective grid access to zero, when the protection of the ground voltage and the neutral limiting device may repeat ground leakage.

2. Scope of application Different protection grounding is applicable to high and low voltage power grids that are generally ungrounded. It is also applicable to low voltage power grids that have adopted other safety measures (such as installing leakage protectors). The protection connection is only applicable to neutral grounding. Low voltage grid.

3. Different line structure If the protective grounding measures are taken, there may be no working zero line in the power grid, only the protective grounding line; if the protective zeroing measures are taken, the working zero line must be set, and the working zero line is used for zero protection. The protective zero line should not be connected to switches or fuses. When installing a disconnector such as a fuse on the working zero line, a protective ground wire or a zero wire must be additionally installed.