A voltage relay is actually an "automatic switch" that uses a smaller current to control a larger current. Therefore, it plays the role of automatic adjustment, safety protection, and conversion circuit in the circuit.
Voltage relay structure and principle
1. Electromagnetic voltage relays are divided into protruding fixed structures, protruding plug-in structures, embedded plug-in structures, etc., and have a transparent plastic cover, which can observe the setting value and specifications of the relay.
2. The relay is of electromagnetic type and operates instantaneously. The magnetic system has two coils, and the coil outlet is connected to the base terminal. Users can connect in series and parallel according to their needs so that the setting range of the relay can be doubled.
3. The scale value and rated value of the relay nameplate are the current (in A) when the coils are connected in series for the current relay, and the voltage (in V) when the coils are connected in parallel for the voltage relay. Turn the pointer on the dial to change the reaction torque of the hairspring to change the action value of the relay.
How to use the voltage relay
1. For the overcurrent (voltage) relay, when the current (voltage) rises to the set value or greater than the set value, the relay will act, the moving closing contact will be closed, and the moving breaking contact will be disconnected.
2. When the current (voltage) drops to 0.8 times the set value, the relay will return, the moving closing contact will be disconnected, and the moving breaking contact will be closed. The closing contact is opened, and the moving and breaking contact is closed.
Voltage relay debugging method
1. Before using the relay, check whether there is any damage during transportation, that is, set the relay on the first set point, turn the movable system in the direction of the magnetic pole by hand, and then release it, the movable system should be turned back to the original position until the stop.
2. When the relay is readjusted, it must be ensured that:
a. The air gap between the moving plate and the magnetic pole should be uniform, and the moving plate and the magnetic pole should not collide under any action conditions;
b. During the action, the movable system shall not be stagnant in the middle position;
. When the pointer rotates from the first scale to the maximum scale, the circles of the hairspring must not touch;
e. When the contacts are in the open position, the total air gap between the dynamic and static contacts is not less than 1.5mm;
f. The gap between the static contact piece and the limiting piece is 0.1mm to 0.3mm.
3. The adjustment of the minimum setting value of the relay is mainly to change the size of the reaction force of the hairspring, and the adjustment of the maximum setting value is mainly to change the air gap between the moving piece and the magnetic pole.
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