E6581158
A-20
1
Q
Disposal
If an inverter is no longer usable, dispose of it as industrial waste.
1.4.3 What to do about the leak current
Warning
Current may leak through the inverter's input/output wires because of insufficient electrostatic capacity on the motor with
bad effects on peripheral equipment.
The leak current's value is affected by the carrier frequency and the length of the input/output wires. Test and adopt the
following remedies against leak current.
(1) Effects of leak current across ground
Leak current may flow not just through the inverter system but also through ground wires to other sys-
tems. Leak current will cause earth leakage breakers, leak current relays, ground relays, fire alarms
and sensors to operate improperly, and it will cause superimposed noise on the CRT screen or display
of incorrect current amounts during current detection with the CT.
Power
supply
ELCB
Inverter
Inverter
M
M
ELCB
Leak current path across ground
Remedies:
1.If there is no radio-frequency interference or similar problem, detach the built-in noise filter ca-
pacitor, using the grounding capacitor disconnecting switch or tap. (See 1.3.2-2)
2.Reduce PWM carrier frequency.
The setting of PWM carrier frequency is done with the parameter
H
.
3. Use high frequency remedial products (Schneider Toshiba electric corporation: Tesys J series
or Esper Mighty Series) for earth leakage breakers. PWM carrier frequency.
4.If the sonsors and CRT are affected, it can be remedied using the reduction of PWM carrier
frequency described in 1 above, but if this cannot be remedied since there is an increase in the
motor's magnetic noise, please consult with Toshiba.
