The power of the submersible sewage pump in general is always increased with increasing flow, popular point is a power curve increase with the rising flow curve, the use of submersible sewage pump will bring about a problem: in the design of sewage pump running condition, sewage pump power is less than rated power of motor. Then use this pump is safe, but when the pump head decreases, the flow will increase, the power also increases. When the flow rate exceeds the design point flow and reaches a certain value, the input power of submersible sewage pump may exceed the motor rated power and cause motor overload and burn. Motor overload operation or protection system action to stop the pump rotation, or to protect the system failure to burn the motor.
Submersible sewage pump head below the design point lift usage, a case in practice is often encountered in the pump selection, the pump head selected too high, but the actual use is to lower the lift pump use. Another situation is that in the use of the pump operating point is not good to determine, in other words, the flow of the pump needs to be regulated, there is a situation is that the pump needs to often change the location of the use of. These three circumstances may cause the pump overload and affect the pump's reliability. It can be said, for the pump without the characteristics of the whole pump (including the sewage pump), the scope of its use will be largely restricted.
Full lift characteristics refers to the so-called power curve increase with the rising flow speed is very slow, it is more desirable when the flow rate increased to a certain value, the power will not rise again, it will decline, that is to say the power curve is a hump curve, if so, as long as we choose the motor rated power is slightly more than the power of hump point value, then in 0 traffic to the entire range of maximum flow, whether you run on that one point, power submersible sewage pump will not exceed the motor power and the pump overload, to have the performance of the pump, whether the selection or use, are will be very convenient and reliable. In addition, the motor power is not too large, can save considerable equipment costs.
