JDH-2 Motor protection relayDetailed product description：

Purpose:
JDH-2 motor protection relay is mainly used for the protection of small and medium-sized motors. It determines the phase of the broken wire and issues an alarm when the motor is running with a broken wire or missing phase. It can also be used for secondary line protection in power systems as a missing phase monitoring component.

Relay model name:




Working Principle:
The schematic diagram of the relay principle is as follows: (see Figure 1)
The relay measures the three-phase voltage. When one phase is missing, the relay will trigger an alarm and maintain its operating state. When the voltage returns to normal, the relay will return. If two of the three phases are disconnected or all three phases are disconnected, the relay will instantly output, but due to the loss of working power, it will return after the action.



Usage:
4.1 Installation method: A single relay is installed in a protruding manner;
4.2 Use: It should meet the working environment conditions of the product;
4.3 Maintenance: This product should be regularly inspected, starting with a visual inspection to check for any loose solder joints on the printed circuit board and any bent wires. Next, check if the DC and AC circuits are working properly.
The product should be able to work reliably under the following conditions
a) Environmental temperature: -10 ℃ to+50 ℃;
b) Atmospheric pressure: 80kPa~110kPa;
c) Relative humidity: The average maximum relative humidity of the wettest month is 90%, and the average minimum temperature of that month is 25 ℃, with no condensation on the surface. When the highest temperature is 40 ℃, the average maximum relative humidity does not exceed 50%;
d) In an environment without conductive dust and corrosive gases that can damage metals and insulation;
e) In media without explosion hazard and not filled with dust (such as coal ash, abrasives, sawdust, etc.);
f) Working position: Tilt in any direction not exceeding 5 ℃ and without severe vibration and impact;
g) The usage location is equipped with rain, snow, wind and sand protection devices and is not filled with water vapor;
h) Places without severe mold presence;
i) Strong external magnetic induction is not allowed in the usage area.
Relay weight
The weight of the relay shall not exceed 1.25kg

Main technical parameters:
3.1 Rated voltage
a) Rated voltage: 380V, 100V
b) Rated frequency: 50Hz.
3.2 Phase indication for missing phases
After the relay is activated, it should indicate the phase of the missing phase.
3.3 The action time of the relay in the event of a phase loss action shall not exceed 50ms.
3.4 Power consumption: At rated voltage, the power consumption of the three-phase AC voltage circuit shall not exceed 5VA/phase.
3.5 Contact breaking capacity
a) DC circuit: Under the conditions of current not exceeding 1A and voltage not exceeding 250V, the external output contact can disconnect a DC inductive load of 30W with a time constant of (5ms ± 0.75ms).
b) AC circuit: Under the conditions of current not exceeding 5A and voltage not exceeding 250V, the external output contact can disconnect the load of the circuit with a power factor coso of (0.4 ± 0.1) of 250VA.
The conductive circuits of the 3.6 dielectric strength relay should be able to withstand an AC test voltage of 2kV (effective value) and 50Hz between the exposed non charged metal parts and the casing, as well as between the input circuit contacts, for a duration of 1 minute without insulation breakdown or flashover.

Wiring diagram behind the relay:
Rear wiring diagram of relay (see Figure 2)



Relay external dimensions and opening dimensions:
Structural form and external dimensions
The relay is based on a static principle and has an modular plug-in structure. The external dimensions and installation dimensions are shown in Figure 4 and Figure 8 of the protruding modular insertion structure.

Ordering instructions:
a) Product model, name, rated voltage;
b) Order quantity;
c) Supply completeness: 1 copy of product manual;
d) Relay accessories: such as base, socket, etc. (must be ordered separately)

JDH-2 Motor protection relay（No image available）