| Brand | Switchgear parts |
| Model NO. | GRV8 21~26 3 Phase Voltage Monitoring Relay |
| Rated frequency | 45Hz-65Hz |
| Series | GRV8 |
True RMS voltage measurement
Adjustable 8-level rated operating voltage via knob
Wide frequency range: 45Hz – 65Hz
High accuracy: <1%
LED status indicators
Compact and lightweight design
DIN rail mounting
CE marked and EN/IEC 60947-5-1 compliant
Engineered for precision, the GRV8-21-26 utilizes true RMS measurement to ensure accurate voltage readings across a frequency range of 45Hz to 65Hz, with an impressive measurement accuracy of less than 1%. Its compact and lightweight design (90 x 18 x 64mm, 68g-71g) allows for easy installation on a DIN rail.With adjustable voltage settings, LED status indicators, and compliance with EN/IEC 60947-5-1 standards, this 3 phase voltage monitoring relay ensures reliability and safety.making it ideal for applications such as moving equipment, agricultural machinery, and refrigerated trucks.
Operating Temperature: -20°C to +55°C
Storage Temperature: -35°C to +75°C
Protection Degree: IP40 (front panel), IP20 (terminals)
Dimensions: 90 x 18 x 64mm
Weight: 68g – 71g
Max. Cable Size: 1×2.5mm² or 2×1.5mm² (solid wire)
Tightening Torque: 0.4Nm
| Function code | Over voltage | Under voltage | Asymmetry | OFF delay time | Phase sequence | Phase failure |
| GYPV-21 | adjustable | available | ||||
| GYPV-25 | 5%…20% | 0.1s…30s | available | available | ||
| GYPV-26 | 15% | -15% | 8% | 2s | available | available |
| GYPV-22 | 5%…25%,OFF | OFF,-25%…-5% | 0.1s…30s | available | available | |
| GYPV-23 | 5%…25%,OFF | OFF,-25%…-5% | 8% | 0.1s…30s | available | available |
| GYPV-24 | 5%…25%,OFF | OFF,-25%…-5% | 5%…20%,OFF | 2s | available | available |

| Model | 3P3W | 3P4W |
| Function | Monitoring 3-phase voltage | |
| Monitoring terminials | L1-L2-L3 | L1-L2-L3-N |
| Supply terminals | L1-L2 | |
| Voltage range | 380-400-415-440-480 (P-P) |
220-230-240-254-277 (P-N) |
| Rated supply frequency | 45Hz-65Hz | |
| Measuring range | 260V-600V | 150V-350V |
| Threshold adjustment voltage | 5%-25%of Un selected or OFF | |
| Asymmetry threshold | 5%-20% or OFF | |
| Hysteresis | 2% | |
| Phase failure value | 70% of Un selected | |
| OFF delay time | Adjustable 0.1s-30s,10% | |
| Measurement error | ≤1% | |
| Delay at power up | 0.5s | |
| Knob setting accuracy | 10% of scale value | |
| Output indication | green LED | |
| Fault indication | red LED | |
| Reset time | 1s | |
| Output | 2×SPDT | |
| Current rating | 8A/AC1 | |
| Switching voltage | 250VAC/24VDC | |
| Min.breaking capacity DC | 500mW | |
| Temperature coefficient | 0.05%/℃,at=20℃(0.05%℉,at=68℉) | |
| Mechanical life | 1*107 | |
| Electrical life(AC1) | 1*105 | |