Frequent electrical problems in waste water treatment operation

Incidents during the operation of the wastewater treatment system are something no one wants, but as technicians, we can’t let the problems happen and run after them to solve them. To be able to prevent unexpected damage, the only thing we can do is recognize those hazards and incidents and take preventive measures. With many years of operation in the field of wastewater treatment, Vietnam Water and Environmental Sanitation Company Limited (VESA) has classified and introduced to readers the common electrical problems encountered in wastewater treatment operations.

1. Trash jam in pump, submersible stirrer

This is one of the most common problems when operating the wastewater treatment system. The reason is that there is no garbage blocking system or the garbage blocking system is not working properly. Leads to large objects entering the treatment tank, causing jamming of pump impellers and submersible agitators.


The remedy is to install a garbage blocking system, adjust as well as install more gabions in the submersible pumps. Carry out periodic garbage collection.

2. The problem of the pump is not up to the water

This problem usually occurs with empty pumps. The reason is that the pump is damaged, leading to a drop of water in the suction pipe, leading to the next time the pump runs, it will not be able to absorb water. In addition, with submersible pumps, there may be a situation where there is no water due to misalignment of the pump coupling at the bottom of the tank or damage to the one-way valve.

The motor is not running in the right direction, the pipe is open, which is also the cause of the pump not getting up.


The remedy is to use pump jacks of well-known brands, installed according to technical standards. Check the direction of rotation and the piping system. Regularly check and pick up trash in the tank to avoid jamming the pump or one-way valve

3. Damage to the electrical junction box outside the treatment tank

The cause of electrical box damage is due to placing the box in a wet location, using a box with a low level of water resistance, which is not suitable. Improper installation leads to water and steam entering, damaging the terminals and connection positions.


It is necessary to use a waterproof box with IP 67-68 for installation locations under the treatment tank. Use cable screws that match the cable type and have rubber gaskets to connect the power cable to the box. Priority is given to putting junction boxes up high and using silicone to fill the gaps, preventing water vapor from entering.

4. Stuck problem, damage to the level indicator

The level indicator float is stuck to the pump, the lead pump wire cannot signal to the electrical cabinet. The float can also damage the internal contacts leading to incorrect operation.


To overcome it, it is necessary to use well-known float companies in the market, proceed to hang the float neatly, away from the pump and other equipment.

5. Moisture oxidizes the device

In the process of wastewater treatment, it is particularly corrosive, which seriously affects the quality of the work items. Especially with equipment and materials located in the wastewater treatment tank area. Even the electrical system is greatly affected such as damage to the cable tray system, oxidation of equipment in the electrical cabinet.


Therefore, it is necessary to conduct sealing of the open positions in the treatment tank to prevent odors as well as moisture from escaping. Use equipment and supplies with suitable materials, with high corrosion resistance such as PVC or Inox 304. Regularly check and replace and overcome oxidized positions.

6. High temperature in station area

Wastewater treatment systems often use air blower systems with high capacity, the amount of heat generated when operating is often very large. Leads to the temperature in the station area is always from 40-45 degrees Celsius or more, greatly affecting electronic equipment and electrical cabinets.


It is necessary to conduct ventilation and cooling for the station area. Separate the electrical cabinet area and the machine placement area if possible. Periodic temperature measurement and need to have a plan to deal with when the temperature exceeds the allowable level.

7. Failure due to improper operation


All of the above incidents can be prevented and predicted if a complete and appropriate operating process is built. Operators need to strictly follow the set procedures. Report immediately when there is an emergency to ensure that the system operates stably, without unexpected problems.

Through the above article, VESA hopes that customers will better understand the common problems of the wastewater treatment system. If you need advice on environmental services, you can contact VESA for the most detailed advice. We have a full package of services from environmental consulting to design, construction and commissioning of environmental treatment systems, re-operation and supply of microorganisms…

VESA always ready to bring the best service experience, in accordance with the needs of our customers./.