rating for Inverter

Well, according to procedure, there are several steps we need to go through:

1. Definition of continuous operation: Operation pattern such as continuous operation or cyclic operation.

2. Capacity selection:

(2.1) Permissible temperature of the motor should not be exceed during operation.

Because temp. characteristics of a motor differs according to: Motor type, inverter control system, output frequency.

(2.2) Can motor be started: The starting torque of motor operated by an inverter is smaller than that of motor operated by a commercial power supply. (low-speed operation or high-speed operation).

Because starting torque of motor varies according to inverter capacity, inverter control system, and torque boost.

(2.3) Acceleration and deceleration capabilities: Motor current is larger during acceleration so we should select inverter that can supply this current. Need to break or not?

3. what kind of load:

4. As a conclusion, select the inverter that has capacity not less than motor capacity.

Dear,

Inverter is to be selected on the basis of KVA , i.e. KW @ PF 0.8

Consudering Star Delta Operation of motor starter ,

Starting current of motor - 5 * 35A = 175 Amp.

No. of Start / Stops / Hr. = _______ times.

Normal Starting capacity of Inverter( is 1.5 times In) = 175 / 1.5 = 116 Amp.

So, KVA capacity of Inverer = 116 * 1.732 * 0.415 = 83 KVA i.e. 66KW

Please consult the Inverter manufacturer, to confirm the starting KVA capacity of Inverter.

HP, in this modern world where people are trying to save every penny. Is that practical when we have to purchase the double capacity of an inverter for an unknown motor application?