Electric motor power calculation at enduring operation mode (S1) and at constant load

There are a lot of mechanisms that work long time with constant load or hardly changed load.

Power calculation is pretty simple if the power of mechanism is known.

Having chosen motor power it is sure the power is used in over temperature. If there is no motor to the calculated power, the more maximum power should be chosen.

As motor operates in long-term mode rarely, so the heating of starting losses can be neglected. But in some issues starting moment should be checked.

For example motor power of pump is specified:

[kWt],

Where - pump productivity, [m³/s];

- calculated overflow height, ;

- water density, ;

- pump efficiency (for higher pressurefor lower pressure);

- transmission efficiency.

,

де - retraction height, ;

- feeding height, ;

- head losses, ;

- free head.

Physic units check:

.

Дата добавления: 2014-01-05