1. Conditions of safe operation
1. Conditions of safe operation
This manual contains notices intended to ensure personal safety, as well as to protect the products
and connected equipment against damage so read it carefully before using the drive.
Not knowing or ignorance of the information contained in it can cause physical injury, death or
damage to the frequency converter and connected equipment.
In the further part of this User manual, the frequency converter, to which this instruction applies, will
be also referred to as the FC, drive or converter.
1.1 Warnings
Incorrect installation, usage, and maintenance of the drive can cause physical injury, death, or damage to the
device and connected equipment.
R I S K O F E L E C T R I C S H O C K !
The dangerous voltage is still present after
disconnecting the power supply
•
Installation, usage, and maintenance of the drive must be performed only by qualified personnel.
•
Before switching on the voltage, make sure the drive has been correctly installed and all housing elements have
been properly assembled.
•
It is forbidden to touch the drive's voltage terminals if it is connected to the power supply.
•
After connecting the drive to the supply voltage, its internal components (without the control terminals) are on the
power supply potential. Touching these components can cause an electric shock.
•
When the drive is connected to the supply voltage, dangerous voltage appears at its output terminals U, V, W even
when the motor is not running.
•
Externally supplied control circuits may carry dangerous voltage even when the input power of the frequency
converter is switched off.
•
The drive contains DC link circuit capacitors that remain charged even when the drive is not powered. It can cause
an electric shock. The time required for self-discharge of capacitors in an undamaged drive is usually between
5÷15 minutes (a higher power rating of the frequency converter means the longer time).
Before starting any installation works, wait at least 5 minutes after disconnecting all power supplies sources and
make sure that voltage on clamps is not present.
CAUTION! The lack of voltage at the connection terminals is not synonymous with the lack of dangerous
voltage in the internal DC circuit of a drive.
•
Don’t make any connections changes when the drive is connected to the power supply.
•
Do not install and use the frequency converter in flammable or explosive atmosphere because it could cause fire or
explosion.
1.2 Basic rules
•
Don’t connect mains voltage to output terminals U, V, W.
•
Don’t measure the voltage endurance of any unit drives.
•
To measure the cables insulation it is necessary to disconnect them from the drive.
•
Do not repair the unit yourself. Any repairs must be performed only by authorized service.
Any modifications or self-repairs of the drive can cause physical injury or death, or damage to the drive and
connected equipment. Any attempt at unauthorised repairs will void any warranty.
•
Don’t touch integrated circuits and any other parts on the drive’s electronic board, as they can be damaged by
electrostatic discharge.
•
Don't connect any capacitors to motor wires (e.g. intended for improvement of power factor).
•
Don't measure output voltage of converter using digital voltmeters without low-pass filter. The voltage can be
measured correctly using an electromagnetic voltmeter.
•
The drive is not designed to operate with periodically switched on/off supply voltage. After turn off supply voltage
wait 5 minutes before turn on it again.
•
If the electric motor runs at low speed (below 25 Hz), additional cooling of the motor is necessary.
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Frequency converter MFC710 type. TWERD Power Electronics
