JD3,JD8 type leakage relayDetailed product description：

Structure and working principle:
JD3 is an electronic current operated leakage relay, mainly composed of zero sequence current transformers, electronic circuits, test circuits, and small relays. The working principle is as follows:
As shown in the figure, when ground leakage occurs in the circuit passing through the zero sequence current transformer, iA+iB+iC+iN ≠ 0. The auxiliary side of the zero sequence current transformer generates an induction signal, which is processed by the electronic circuit. When the leakage current reaches the operating value, the thyristor conducts the small relay to close, and uses normally open and normally closed contacts to control the main line relay or contactor to disconnect and cut off the faulty line.
The test circuit is composed of resistor R5, button AN1, and wiring. When button AN is pressed, a current flows through the transformer, which is equivalent to leakage in the main circuit. The leakage relay should operate.

1、 The JD3-FS series leakage device is suitable for AC voltage up to 660V, frequency of 50Hz, current up to 630A and below, in transformer neutral grounding circuits. Leakage relays can be combined with circuit breakers, AC contactors, magnetic starters, etc. with shunt release or voltage loss release to form leakage protection devices for leakage and electric shock protection. They can also be combined with various sound and light indicators such as buzzers and signal lights to form leakage alarm devices. The action time of the leakage relay is divided into fast type and delay type, and when used together, it can provide graded selective protection for lines and branches. It is an improved model of JD3. This relay can completely replace the JD3 series leakage relay of the past.

rated voltage	Diameter of transformer through-hole ￠ (mm)				Rated leakage current (mA)	Rated leakage non operating current (mA)	Action time (s)		Rated control capacity
	And maximum rated current reference value (A)						Quick type	Slo-Blo
660/380	25/100	45/200	75/400	100/630	100 or user-defined	50 or user-defined	≤0.1	0.2,0.4 0.8,1 1.5,2	~220V 3A

JD3 and JD8 leakage relays