NewTrend · Frequency monitoring relay
Product overview
NewTrend RF8-01 supervises overfrequency and underfrequency in nominal 50Hz or 60Hz AC circuits. It is powered from the monitored voltage at A1-A2, with a rated AC 120-277V supply and operating limits of AC 100-310V. The front controls set the upper and lower frequency offsets, threshold multiplier, memory mode and 0.1-10 second tripping delay. The relay measures 40-70Hz with a specified error of ±0.05Hz and provides two SPDT outputs rated 8A AC-1.
Technical selection summary
| Model | RF8-01 |
|---|---|
| Function | Overfrequency and underfrequency monitoring |
| Nominal monitoring frequency | 50Hz or 60Hz, selected by Y1-Y2 wiring |
| Rated monitored supply | AC 120-277V |
| Operating voltage limits | AC 100-310V |
| Supply/measurement terminals | A1-A2 |
| Power source | From the monitored AC voltage |
| Frequency measurement range | 40-70Hz |
| Upper threshold offset F> | -2 to +10Hz relative to selected nominal frequency |
| Lower threshold offset F< | -10 to +2Hz relative to selected nominal frequency |
| Threshold scaling | x1 or x2, using the front multiplier/mode control |
| Hysteresis | Fixed 0.3Hz |
| Measurement error | ±0.05Hz |
| Tripping delay Tt | Adjustable 0.1-10 seconds; 10% setting accuracy |
| Power-up delay | 0.5 second |
| Memory mode | With or without memory, selected on the front |
| 50Hz selection | Y1-Y2 open |
| 60Hz selection | Y1-Y2 linked; make this connection with power off |
| Output contacts | 2 SPDT |
| Output terminals | 11-12-14; 21-22-24 |
| Contact rating | 8A, AC-1 |
| Switching voltage | 250VAC / 24VDC |
| Minimum DC breaking power | 500mW |
| Output indication | Green R LED |
| Fault indication | Red Fault LED |
| Mechanical life | 10,000,000 operations |
| Electrical life (AC-1) | 100,000 operations |
| Temperature coefficient | 0.05% per degree C at 20 degrees C |
| Operating temperature | -20 to +55 degrees C |
| Storage temperature | -35 to +75 degrees C |
| Mounting | DIN rail to EN/IEC 60715; 18mm module |
| Protection | IP40 front panel; IP20 terminals |
| Operating position | Any |
| Overvoltage category / pollution degree | III / 2 |
| Maximum conductor size | Solid: 1 x 2.5mm² or 2 x 1.5mm²; with sleeve: 1 x 2.5mm² (AWG 12) |
| Terminal tightening torque | 0.4Nm |
| Body dimensions | 90 x 18 x 64mm |
| Overall height in drawing | 95mm including rail-clip projection |
| Weight | 59g |
| Referenced standard | EN/IEC 60947-5-1 |
Operation
- For nominal 50Hz monitoring, leave Y1-Y2 open. For nominal60Hz, link Y1-Y2. The original manual requires making this connection with power off.
- Set F> and F< as offsets from the selected nominal frequency. The multiplier and operating-mode control provides x1/x2 scaling and operation with or without memory.
- Set Tt from 0.1 to 10 seconds to coordinate response to frequency excursions. Power-up delay is 0.5 second.
- Set the upper threshold above the lower threshold. Both thresholds cannot be set to OFF simultaneously; the original manual shows that invalid settings make all LEDs flash and disconnect the outputs.
Typical applications
- Frequency supervision in motor and equipment control circuits
- Generator and normal/emergency supply monitoring
- Frequency-alarm or interlocking circuits with two changeover outputs
View or download RF8-01 frequency-monitoring instruction manual V1.0 (PDF)
Product reference images and drawings
Original frequency specifications and front-panel setting controls
Original 50/60Hz jumper, memory timing, valid settings and dimensions
Follow the original mode and timing diagrams for memory operation. Set the 50/60Hz jumper only with power off, as instructed in the manual. Match the external switching circuit to the contact rating and required response to frequency faults. Installation and wiring must be performed by qualified electricians.
