CHINT · Three-phase voltage protection relay
Product overview
The CHINT NJYB2 voltage protection relay monitors three-phase, three-wire AC control circuits. Choose NJYB2-G for phase-loss and phase-sequence monitoring, or NJYB2-H when adjustable overvoltage, undervoltage and voltage-unbalance protection is also required.
Technical selection summary
| Manufacturer model / supply | NJYB2-G or NJYB2-H; AC 380 / 400 / 415 V, 50 Hz |
|---|---|
| G protection / contacts | Phase loss and phase sequence; one changeover contact |
| H protection / contacts | Phase loss, phase sequence, overvoltage, undervoltage and three-phase voltage unbalance; one changeover contact plus one NC contact |
| Phase-loss / sequence response | ≤1 s |
| H overvoltage setting | 1.05–1.3 × Us, adjustable; delay 0.1–10 s, adjustable |
| H undervoltage setting | 0.7–0.95 × Us, adjustable; delay 0.1–10 s, adjustable |
| H unbalance setting | 5%–15% × Us, adjustable; delay 0.1–10 s, adjustable |
| Contact duty | AC-15: 0.47 A at 415 V; Ith 3 A is a separate thermal reference |
| Durability reference | Electrical life 100,000 operations; mechanical life 1,000,000 operations under manufacturer conditions |
| Mounting / environment | Rail mounting; −25 to +70 °C |
| Dimension reference | 36 ±0.1 mm, 65.5 ±0.2 mm and 94 mm maximum envelope references; match the manufacturer drawing for orientation and mounting clearances |
Match the rated control voltage to the actual three-phase supply and follow the G or H terminal diagram. H protection adjustments are not available on G. The 0.47 A contact rating is specified at AC-15 415 V; it is not a motor current or the 3 A thermal rating. Use the relay to control a properly rated contactor or control circuit.
Typical applications
- Phase-loss and phase-sequence monitoring in three-phase control panels
- Adjustable voltage and unbalance supervision with NJYB2-H
Specify your enquiry
For a focused quotation, include:
- NJYB2-G or NJYB2-H, rated supply voltage and quantity
- Required protection thresholds, delay settings and monitored circuit
- Controlled contactor/load duty, wiring and rail/panel installation requirements
Product reference images and drawings
Match the exact model, construction and supplied revision. Family reference pages can show other ratings or versions.
