HOW OFTEN DO YOU NEED TO CHANGE THE OIL IN A SUBMERSIBLE ELECTRIC PUMP?
The oil in the lubrication chamber ensures the mechanical seals are properly lubricated, protecting them against wear, overheating and sticking.
In normal operating conditions the oil should be changed every 10,000 / 15,000 hours at the most.
If, when changing the oil, water is found in the oil chamber, check the seals and mechanical parts immediately and repair or replace them if necessary. Water in the oil chamber will cause the pump to break down.
HOW MUCH DOES A SUBMERSIBLE PUMP HAVE TO BE IMMERSED IN THE LIQUID TO WORK CORRECTLY?
The minimum level of immersion for a submersible electric pump depends on the type of service and the load the motor is subjected to. For continuous service, the pump must be completely immersed in the pumped fluid; for intermittent service, the pump also works when partially immersed but it must be allowed to rest for reasonable periods to prevent the motor from overheating.
Some of our models are fitted with a special cooling casing so they can operate continuously even when partially immersed.
WHAT IS CAVITATION?
Cavitation is the formation and violent implosion of vapour bubbles.
To prevent cavitation, it is very important that the pressure in the pump’s suction area is not lower than the vapour pressure of the pumped liquid.
Cavitation can occur for a number of reasons, such as the temperature of the liquid, the type of liquid, the atmospheric pressure, the type of system etc..
You know your pump is experiencing cavitation when you hear a continuous crackle or hammering coming from the hydraulics.
Cavitation should be avoided in electric pumps as it can compromise their performance in a very short space of time.
WHAT IS A PUMP PERFORMANCE CURVE?
The performance of every pump and, therefore, that of submersible electric pumps, is normally summarised in a graph called the characteristic curve of the pump. In this Cartesian graph, the pump data is represented on a curve which shows the relation between flow (Q) and head (H). It is an intuitive system to understand the flow at a certain head and vice versa. If you are familiar with the data of the system where the pump will be installed and you use the characteristic curve graph, you can make a good approximation of the working point.
WHAT ARE THE MAIN CAUSES OF OVERLOAD IN A PUMP MOTOR?
During operation, a pump motor can experience overload. Knowing the most frequent causes of overload can help prevent malfunctions. The main reasons for overload can be: the impeller is blocked by foreign bodies, the mechanical parts block due to excessive stopping times, the density of the liquid is greater than the maximum permitted density etc..
If you have any doubts, contact your dealer or specialised Hydropompe maintenance technician.
HOW DO YOU TRANSPORT AND STORE ELECTRIC PUMPS IN A WAREHOUSE?
When you store an electric pump in the warehouse, it should be cleaned thoroughly beforehand. Do not use compounds derived from hydrocarbons to do this.
Always keep an electric pump indoors, in a dry, dust-free environment. Stand it in such a way it cannot roll over and fall.
If the pump is to be idle for long periods of time, every so often turn the impeller by hand to stop the parts from sticking.
Always handle electric pumps with care and caution, using appropriate lifting equipment that complies with safety regulations.
If you need to move the pump, always do so using the special handle or eyebolts. Never lift an electric pump by the power supply cables.
When placing the pump back down, make sure you do not damage its cables or bend them sharply. Do not leave a pump exposed to the weather or water.
HOW MANY DECIBELS DOES AN ELECTRIC PUMP PRODUCE DURING OPERATION?
The acoustic pressure level permitted by the machine in the envisaged operating range is below 70 dB (A). The sound level of Hydropompe electric pumps has been measured in compliance with the ISO 3746 standard and the measurement points, according to Directive 2006/42/EC, are one metre from the reference surface of the machinery and 1.6 metres from the floor or access platform.