RR3 Series Rail Mount 230VAC 1CO 10A Three Phase Analog Voltage Protection Electronic Relay
The RR3VP02 extends EMAS's voltage protection relay to three-phase supplies, adding phase sequence and phase loss detection alongside the same adjustable low/high voltage thresholds as the single-phase RR3VP01. That phase monitoring matters for three-phase motors, which can be damaged by running on the wrong rotation or with a phase missing entirely.
A simple to install voltage protection relay for three phase supplies:
- Easy adjustment of setpoints by potentiometer
- Time delay 0-20 seconds
- Status LEDs for easy diagnosis
- Checks for phase sequence and phase loss
Technical Details
Frequently Asked Questions
What's the difference between this and the RR3VP01?
This RR3VP02 is for three-phase supplies and adds phase sequence and phase loss detection. The RR3VP01 is single-phase and monitors voltage level only — choose based on your supply type.
Why does phase sequence matter for motors?
Running a three-phase motor with the wrong phase rotation can reverse its direction unexpectedly; this relay detects incorrect sequence and trips before the motor runs the wrong way.
What happens if one phase is lost?
The relay detects phase loss and trips, protecting the motor from running single-phased, which can cause overheating and premature failure.
What does the time delay setting do?
It delays tripping by 0-20 seconds after detecting a fault condition, letting the relay ride through brief transients rather than tripping on every momentary fluctuation.
Industry Applications
- Three-phase motor protection — preventing damage from phase loss, incorrect sequence, or voltage excursions
- Generator & backup power systems — detecting out-of-tolerance three-phase supply before it reaches equipment
- Panel builders & OEMs — adding comprehensive voltage and phase supervision to three-phase control circuits