How to wire the leakage protection switch
1. According to the power supply mode of different electrical equipment, choose different leakage protection devices
For electrical equipment powered by single-phase 220V power supply, two-pole two-wire or single-pole two-wire leakage protectors should be used.
For electrical equipment powered by a three-phase three-wire 380V power supply, a three-pole leakage protector should be used.
A three-pole four-wire or four-pole four-wire leakage protector should be used for electrical equipment powered by a three-phase four-wire 380V power supply or a circuit shared by single-phase equipment and three-phase equipment.
2. Select the rated leakage current of the leakage protector according to the normal leakage current of the electrical circuit
Select the rated leakage current of the leakage protector The normal leakage current value that may occur in the protected circuit and equipment should be fully considered.
The rated leakage non-operating current of the selected leakage protector should be less than 2 times the maximum value of the normal leakage current of the electrical circuit and equipment.
The rated voltage, rated current, short-circuit breaking capacity, rated leakage current and breaking time of the leakage protector shall meet the requirements of the protected power supply line and electrical equipment.
The leakage protection switch is correct wiringmethod
1. When used for branch line protection, each branch line should have its own dedicated zero line, and the neutral lines of two adjacent branch lines shall not be connected. If the two branch lines are connected, the current in the zero line will flow each other, which will destroy the working current balance in the zero-sequence current transformer and cause the leakage protector to malfunction. If you want to use the zero line of the power branch line as the zero line of the lighting branch line, it will cause the leakage protector of the power branch line to act.
2. An electrical equipment can only be connected in one protection branch, not in two branch circuits, not in front of zero-sequence transformer, and not in one-line-one-ground system. Power supply, otherwise, it will cause the leakage protector to malfunction.
3. Electrical equipment with and without a leakage protector shall not share a grounding device. For example, when the insulation of the motor M1 is damaged and the casing is electrified, the casing of the motor M2 is also electrified. Since the current does not pass through the leakage protector, it does not play the role of leakage protection.
4. The single-phase load should be distributed as evenly as possible. If the distribution is uneven (for example, the line of one phase is too long and the equipment is concentrated), the leakage current of the phase with heavier load is too large, so the three-phase unbalanced leakage current of the main line increases, and when it reaches a certain value, the main line will be damaged. The leakage protector at the head end operates.
5. The protected lines (including the working zero line) should all pass through the through holes of the zero-sequence current transformer and the leakage protector, and the three-pole leakage protector should not be used to replace the four-pole three-phase four-pole ,leakage protector. If it is a three-phase five-wire system, the protective ground wire must not pass through the transformer of the leakage protector, but must be connected to the zero trunk line at the front end (incoming line end) of the first-pole leakage protector or the repeated grounding pole.
Now I will take 1P+N leakage protection switch, 2P leakage protection switch and 3P leakage protection switch as examples to teach you how to wire the leakage switch.
The wiring method of 1P+N leakage protection switch
The usage rate of 1P+N leakage protection switch in home improvement is very high. The wiring with the zero line has strict requirements. It is not judged according to our conventional left zero right fire or left fire right zero. The wiring should be carried out according to the mark on the leakage protection switch, that is, the live wire is connected to L or not. On the marked terminal, the neutral wire is connected to the terminal marked with N.
The wiring method of 2P leakage protection switch
Compared with 1P+N leakage protection switch, 2P leakage protection switch takes up more space and is expensive Higher, but the safety of 2P leakage protection switch is significantly higher than that of 1P+N leakage protection switch, and is now more and more used;
The wiring of 2P leakage protection switch is not strict It is required, that is to say, the terminals of the incoming and outgoing lines can be connected to the live wire and the neutral wire at will. The conventional connection methods include left zero and right fire and left fire and right zero. Both of these connection methods are actually possible, we only need to ensure that the incoming line is connected. It should be consistent with the outgoing wiring.
3P leakage protection switch wiring method
3P leakage protection switch is not seen in most of our homes, but only in villas In the home decoration, the usage rate is very low, so I will only give you a brief talk about it.
The wiring of the 3P leakage protection switch also has strict requirements. The neutral line N will be marked on the leakage protection switch. When we connect, the three terminals on the left are generally connected to the three of the live wire. Phase, the one marked with N on the right is used to connect the neutral line.
Residual current switch wiring precautions
1. The neutral wire on the load side of the leakage protector shall not be shared with other circuits.
2. When the leakage protector is marked with the load side and the power supply side, the wiring should be installed and connected in accordance with the regulations, and the connection should not be reversed.
3. When installing a leakage protector with short circuit protection, it must be ensured that there is sufficient arcing distance in the direction of arc spraying. The arcing distance is specified by the manufacturer of the leakage protector.
4. The neutral line and the protection line must be strictly distinguished during installation. The neutral line of the three-pole four-wire or four-pole leakage protector should be connected to the leakage protector. The neutral line passing through the leakage protector shall not be used as a protection line, and shall not be repeatedly grounded or connected to the external leakage conductive parts of the equipment. The protection wire shall not be connected to the leakage protection device.
