The document describes a TRMS 3-phase over and under voltage, phase sequence and phase loss monitoring relay. It detects the presence of all 3 phases and their correct sequence. It also detects if the 3-phase-phase or phase-neutral voltages are within the set limits, with upper and lower limits separately adjustable. The relay has a selectable measuring range, adjustable delay function, and LED indication. It is designed for mounting on a DIN-rail.
The DPB71 is a true RMS 3‑phase (or 3‑phase+N) monitoring relay that detects over‑ and under‑voltage, phase sequence, and phase loss. It offers adjustable upper and lower voltage limits, a selectable measuring range via DIP‑switches, and a programmable delay from 0.1 to 30 s. The relay outputs a 5 A SPDT contact and includes LED indicators for power, alarm, and relay status.
The device is housed in a 35.5 mm DIN‑rail compatible enclosure (35.5 × 81 × 67.2 mm, approx. 100 g) and operates from 208‑480 VAC supplies with a 15 % tolerance. It meets UL, CSA, and CE approvals, and complies with IEC standards for over‑voltage category III and electromagnetic compatibility.
| Measuring range (low voltage) | 208‑240 VAC |
|---|---|
| Output type | 5 A SPDT relay |
| Rated insulation voltage | 250 VAC |
| Contact rating (resistive) | 5 A @ 250 VAC |
| Mechanical life | > 30 × 10⁶ operations |
| Electrical life | > 10⁶ operations (5 A, 250 V, cos φ = 1) |
| Operating frequency | < 7200 operations/h |
| Dielectric strength (rms) | 2 kV rms |
| Dielectric strength (impulse) | 4 kV (1.2/50 µs) |
| Housing dimensions | 35.5 × 81 × 67.2 mm |
| Weight | Approx. 100 g |
| Approvals | UL, CSA, CE |
It provides a 5 A SPDT (single‑pole double‑throw) relay output.
The measuring range is selected by setting the DIP‑switches on the device.
It is approved by UL, CSA, and carries CE marking.