WQ/EC small submersible sewage pumps are mainly used in municipal engineering, building construction, industrial sewage and sewage treatment situations to discharge sewage, wastewater and rainwater containing solids and short fibers.

1. The power supply is 380V, three-phase, 50Hz.
2. The medium temperature does not exceed 40°C, the PH value is 4-10, and the medium density is ≤1050kg/m3.
3. The minimum liquid level should comply with the liquid level marked with “▽” in the installation dimension diagram.
4. It cannot be used in media that are highly corrosive and contain highly abrasive solid particles.
5. The diameter of the solid matter in the medium should not be greater than 80% of the minimum flow channel size of the pump. For the flow channel size, see the “Main Parameters” of each pump below. The length of the fibers in the medium is not greater than the discharge diameter of the pump.

1. Selected pump body and impeller

CAD technology is used to repeatedly modify the design to ensure that the pump body and impeller are optimally matched so that fibers and debris can easily pass through without getting entangled and blocked. The impeller is strictly balanced, resulting in small vibration and smooth operation of the pump.

2. Highly reliable submersible motor

The specially designed and manufactured submersible motor has a protection level of IP68 and a stator winding with Class F insulation. Due to the good cooling effect during submersible operation, the actual temperature rise of the winding is low, making the motor more durable.

The motor dissipates heat through the casing. As long as the medium submerges half of the height of the motor stator, it can run reliably and safely. The more submerged, the more conducive to the cooling of the motor.

The cable is a sewage-resistant heavy-duty rubber-sheathed flexible cable. The cable core cross-section is selected for continuous full-load operation at an ambient temperature of 40°C, and is very reliable. The cable is re-fixed on the handle to avoid damage during transportation, installation and use.

3. The motor has tight sealing and strict inspection.

1) Shaft sealing

Two independent single-end mechanical seals are arranged on the pump side and motor side respectively to form two shaft seals. The leakage volume is only less than one-tenth of the double-end mechanical seal. The lubricating oil in the oil chamber lubricates and cools the friction pair of the motor side mechanical seal.

The mechanical seal on the pump side that contacts the medium uses a silicon carbide/silicon carbide “hard-on-hard” friction pair, which has high hardness and low friction coefficient and is not prone to wear and failure;

The mechanical seal on the motor side, which is entirely immersed in oil, uses a graphite/silicon carbide “soft-to-hard” friction pair. The friction coefficient is very low and it is easy to “run in”, making the seal reliable. The small gap between the impeller and the pump cover can prevent impurities from entering the shaft seal cavity while maintaining good working conditions of the mechanical seal. The rubber parts of the mechanical seal are made of nitrile rubber with excellent oil resistance, and the springs and other structural parts are made of stainless steel.

2) Full sealing of cables

The WQ/EC pump motor cable adopts a fully sealed structure with a cast head. The cable sheath, cable core and cast head are vulcanized into a whole to ensure that water will not enter the motor cavity through the cable sheath or the gap between the wire cores. However, the cable ends should not be exposed to water. Water entering the cable will seriously reduce the insulation resistance of the cable and affect safety.

3) Seal between parts

O-rings are used as reliable static seals at the joints between the parts.

4) Sealing inspection

Parts can only be assembled after passing the pressure test. Each pump undergoes strict air pressure tests during and after assembly to ensure the sealing of the motor.

4. Reliable bearing configuration

We use famous brand and high-quality deep groove ball bearings with sufficient load margin to ensure reliable operation of the product.

5. Jet mixing function

A spray mixing hole is opened on the pump body. When the pump is running, the pressure water in the pump forms a high-speed jet stream through the spray hole for powerful stirring, suspending a large range of impurities, which are sucked into the pump and then drained away. Precipitation will not form within a wide range, which is superior to mechanical stirring only at the pump suction inlet.

6. Protection device

An overheating protection element is installed in the motor winding. When the winding temperature exceeds the specified temperature, the overheating protection element lights up the “overheating” indicator light through the electric control cabinet and automatically shuts down the machine. Remind the operator to check to find out the cause of motor overheating. After the winding temperature drops, the overheating protection element will automatically reset and the motor will return to the start-up state, but it must not be started until the fault that caused the winding overheating is eliminated.

A water leakage probe is installed in the oil chamber. When the mechanical seal on the impeller side is damaged and the water in the leakage oil chamber reaches a certain level, the two electrodes of the water leakage probe are connected and an alarm signal is sent through the electric control cabinet (the indicator light is on) to remind the operation Personnel should promptly check the mechanical seal or replace the oil in the oil chamber.

For power 5.5kW and 7.5kW, a leakage probe is installed in the lower cavity of the motor. When the mechanical seal on the motor side fails, the oil or water in the oil chamber enters the inner cavity of the motor through the bearing chamber. The leakage probe installed in the lower cavity of the motor sends an alarm signal through the electric control cabinet (the water leakage indicator light turns on) and the pump automatically stops running.Remind the operator to inspect the pump.

List of motor protection components installed in the pump:

Viewed from the pump suction port, the impeller rotates counterclockwise.

Light blue (U), black (V), and brown (W) are three-phase power lines.

The yellow/green two-color wire (11) is the ground wire and signal common wire.

White (14) is the stator winding thermistor signal line.

Purple (12) is the signal line of the oil chamber leakage probe.

Pink (13) is the water leakage probe signal line under the motor cavity (only 5.5kW and 7.5kW)

1. When ordering, please indicate the product name, model, installation form, optional parts, spare parts, etc.
   The impact of medium gravity on power should be taken into consideration when selecting models. Users are warmly welcome to consult our company’s technical department for technical issues.
2. The standard length of the motor cable is 5m. It can be optionally increased in length units of 5m (such as 10m, 15m…). The optional cable length should be stated when ordering and noted on the order.
3. Complete sets of supplied parts are supplied according to the installation method selected by the user. Optional parts and spare parts must be ordered separately by the user.
4. Due to the simple design of the coupling device, only ordinary water pipes or steel pipes are needed for the guide rods. We have previously provided the specifications and length calculation method of the water pipe or steel pipe used as a guide rod. Users only need to purchase the water pipe or steel pipe by themselves, cut it into the required length, and then use it. Therefore, when the guide rod is not installed as a coupling complete set of supplied parts. When users need guide rods provided by our company, they must order separately and write them into the order.