Guides · TOSUNLUX
How to protect a pumping station?
A submersible or surface pump is often far from the grid, fed by a long line where the voltage varies, and unattended. It must protect itself: against bad voltage, the loss of a phase, overload and dry running. Here are the suitable TOSUNLUX (Tosun) protections.
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The short answer
- Voltage and overcurrent, with display: TDP-2-3 in three phase (63 or 80 A).
- Phase sequence and phase loss, imbalance: TRV8 phase monitoring relay.
- Motor overload and short circuit: MP2 motor circuit breaker, or TSC1-D contactor with TSR2-D thermal overload relay.
- Dry running: TRL8 electrode level relay, or TSY-3 float switch.
- All in an IP65 weatherproof enclosure.
1. Voltage and current
Too low a voltage overheats the pump motor; too high a voltage wears it out. The TDP-2-3 monitors the 380 V three-phase voltage (overvoltage thresholds 390–500 V, undervoltage 260–370 V), displays voltage and current on the front and also cuts off on overcurrent, with a threshold adjustable from 1 A up to the rating (63 or 80 A). It restores the supply after an adjustable delay. In single phase, the TDP-2-1 does the same job at 40 or 63 A.
2. The phases
A lost phase makes a three-phase motor run on single phase: it overheats and can burn out within minutes. A phase reversal makes the pump run backwards. The TRV8-05, on an 18 mm module, monitors phase sequence and phase loss, overvoltage and undervoltage (adjustable from 2 to 20%) and imbalance (8%), with a delay adjustable from 0.1 to 10 s. Its output contact controls the coil of the pump contactor.
3. The motor
The motor starter is sized from the power and nameplate current of the pump: see the guide contactor and thermal overload relay for a motor. Up to 18.5 kW, an MP2 / MP3 motor circuit breaker protects against overloads and short circuits; above that, a TSC1-D contactor with a thermal overload relay and short-circuit protection upstream.
For a single-phase pump, the TCP-2 run capacitor (2.5 to 100 µF, 250 or 450 V) is replaced with an identical value, read on the old capacitor or on the motor nameplate.
4. Dry running
A pump running without water destroys itself. The TRL8 level relay measures the level in a well, a basin or a tank through electrodes, for conductive liquids such as water: the TRL8-01 handles two levels, the TRL8-02 one or two levels, for filling or emptying. Sensitivity is adjustable from 5 to 100 kΩ and the probe cable can reach 800 m (at 25 kΩ).
The TSY-3 float switch (3, 5 or 10 m cable, IP68) directly controls a single-phase pump up to 0.75 kW at 220 V; above that, it controls the coil of a contactor.
Summary
| Risk | TOSUNLUX protection | What it does |
|---|---|---|
| Voltage out of range | TDP-2-3 (or TDP-2-1) | Cuts off and restores after a delay, displays V and A |
| Overcurrent | TDP-2-3 · MP2 · TSR2-D | Cuts off above the set threshold |
| Phase loss or reversal | TRV8-05 | Opens the contactor control circuit |
| Short circuit | MP2 / MP3 or upstream breaker | Magnetic trip |
| Dry running | TRL8 · TSY-3 | Stops the pump below the low level |
| Rain, dust | HT / HB IP65 enclosure | Protects the devices |
Frequently asked questions
How to protect a pump against dry running?
With a TRL8 electrode level relay in the well or tank, or a TSY-3 float switch that stops the pump below the low level.
How to protect a three-phase pump against the loss of a phase?
With a TRV8-05 phase monitoring relay, which monitors phase sequence, phase loss and imbalance, plus a thermal overload relay or a motor circuit breaker.
Which voltage protector for a pump?
The TDP-2-3 in three phase (63 or 80 A) or the TDP-2-1 in single phase: they monitor voltage and current and also cut off on overcurrent.
Can a float switch control the pump directly?
The TSY-3 directly controls a single-phase pump up to 0.75 kW at 220 V. Above that, it controls the coil of a contactor.
TOSUNLUX series mentioned
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