The UL‑E2 motor protector from Julong Electric provides comprehensive overload, stall, phase‑loss and imbalance protection for three‑phase motors.
The UL‑E2 series motor protector is a passive, fully enclosed, through‑core design that protects three‑phase motors against symmetric faults such as overload, stall, over‑voltage, under‑voltage and asymmetric faults like phase loss and current imbalance. It operates without an external power supply and uses a smart zero‑cross solid‑state relay for reliable, spark‑free switching.
Installation is straightforward: pass the three motor conductors through the dedicated wire holes, connect the output interface in series with the AC contactor secondary circuit, and set the current dial to the motor’s rated current. The device includes LED indicators for phase status and offers both reverse‑time and fixed‑time over‑current characteristics, making it suitable for harsh environments and automatic control applications. This manual is written in Chinese.
| Current adjustment range | 1/2.5 A to 256/640 A |
|---|---|
| Applicable motor power | 0.5 kW to 320 kW |
| Start delay time | 5 s, 10 s or 20 s (selectable) |
| Output interface control current | 1 A AC (or 2 A AC) |
| Dimensions (L×W×H) | 90 mm × 56 mm × 31 mm |
| Mounting size | 38 mm × 64 mm |
| Protection functions | Phase‑loss, over‑current, overload, stall, three‑phase current imbalance |
| Applicable voltage | 220 V, 380 V, 660 V, 1140 V |
| Frequency range | 45 Hz – 65 Hz |
| Operating temperature | -40 °C to +60 °C |
| Maximum humidity | < 90 % at 25 °C |
| Output interface reset time | ≤ 60 s |
| Output voltage limit | ≤ 50 V |
| Output current limit | ≤ 200 mA |
It protects against phase loss, over‑current, overload, stall and three‑phase current imbalance faults.
No, the protector has no built‑in temperature protection; users must monitor motor temperature and ensure proper ventilation.