Inverter Application Precautions; Selection; Installation - Omron VARISPEED E7 User Manual

Inverter Application Precautions

Selection

Observe the following precautions in selecting an Inverter.
Installing Reactors
A large peak current will flow in the power input circuit when the Inverter is connected to a large-capacity
power transformer (600 kVA or higher) or when switching a compensating capacitor. Excessive peak current
can destroy the rectifier section. To prevent this, install a DC or AC reactor (optional) to improve the power
supply power factor.
DC reactors are built into Inverters of 22 and more.
If a thyristor converter, such as a DC drive, is connected in the same power supply system, connect a DC or
AC reactor regardless of the power supply conditions shown in the following diagram.
Inverter Capacity
When connecting special motors or multiple motors in parallel to an Inverter, select the Inverter capacity so
that the rated output current of the Inverter is minimum 1.1 times the sum of all the motor rated currents.
Initial Torque
The startup and acceleration characteristics of the motor are restricted by the overload current ratings of the
Inverter that is driving the motor. The torque characteristic generally is different from those when starting a
motor on the power supply directly. If a large initial torque is required, select an Inverter one size bigger or
increase the capacity of both, the motor and the Inverter.

Installation

Observe the following precautions when installing an Inverter.
Installation in Enclosures
Install the Inverter in a clean location where it is not subjected to oil mist, dust, and other contaminants, or
install the Inverter in a completely enclosed panel. Provide cooling measures and sufficient panel space so that
the temperature surrounding the Inverter does not exceed the allowable temperature. Do not install the Inverter
on wood or other combustible materials.
Installation Direction
Mount the Inverter vertically to a wall or other vertical surface.
10-2
DC or AC reactor
Power supply
Required
capacity (kVA)
Inverter capacity (kVA)
DC or AC reactor
Not required