8 Selection And Configuration Of Peripheral Facilities; Options - DEMA D5M Series Manual

NO.8 Selection and Configuration of Peripheral Facilities
No.8 Selection and Configuration of Peripheral Facilities

8.1 Options

Name
Breaker and leakage switch
for connection
Electromagnetic contactor
Surge absorber
Isolation transformer
DC reactor
AC reactor
Brake resistor and brake unit
1. Leakage switch
The inside of inverter, inside of motor and input and output leads have earth electrostatic
capacitance and the inverter has relatively high carrier frequency, so large earth leakage
current is induced to the inverter, which is more obvious for high-capacity machines; the
application of leakage switch may cause misoperation of protection circuit, so the attention
should be paid to the selection of leakage switch during the application, simultaneously
carrier frequency shall be reduced and the lead shortened appropriately.
2. AC reactor
AC reactor can be used for suppressing higher harmonic of inverter input current, improving
input power factor of the inverter and preventing leakage-induced impact. It is suggested to
use input AC reactor under following circumstances:
1) Unbalanced three-phase power;
2) The same power supply is connected with thyristor or switch-controlled power factor
compensating device;
82
Protect the connection of inverter, be sure to set breaker
on power side, and please use the leakage switch with
higher harmonic prevention
Set electromagnetic contactor to prevent burning out
brake resistor and connect surge absorber while
applying.
Absorb switching surge current of electromagnetic
contactor and relay for controlling
Isolate input and output effects of the inverter and
produce effect on reducing the interference
Improve input power factor of the inverter
Improve input power factor of the inverter and prevent
surge voltage impact
Consume recovered energy of the motor and shorten
deceleration time
Function