Remedies For The Interferences From The Surrounding Electromagnetic; Equipments To The Inverter; Remedies For The Interferences From The Inverter To The Surrounding; Electromagnetic Equipments - Powtran PI9100 Series Manual

3) It is recommended that the output power cables of the inverter shall use shield
cables or steel pipe shielded cables and that the shielding layer shall be grounded
reliably, the lead cables of the equipment suffering interferences shall use twisted-pair
shielded control cables, and the shielding layer shall be grounded reliably.
4) When the length of motor cable is longer than 30 meters, it needs to install
output filter or reactor.

6-3-3.Remedies for the interferences from the surrounding electromagnetic

equipments to the inverter

Generally the electromagnetic interference on the inverter is generated by plenty of
relays, contactors and electromagnetic brakes installed near the inverter. When the
inverter has error action due to the interferences, the following measures is
recommended:
1) Install surge suppressor on the devices generating interference;
2) Install filter at the input end of the inverter, please refer to Section 6.3.6 for the
specific operations.
3) The lead cables of the control signal cable of the inverter and the detection line
shall use the shielded cable and the shielding layer shall be grounded reliably.

6-3-4.Remedies for the interferences from the inverter to the surrounding

electromagnetic equipments

These noise interferences are classified into two types: one is the radiation
interference of the inverter, and the other is the conduction interference of the inverter.
These two types of interferences cause that the surrounding electric equipments suffer
from the affect of electromagnetic or electrostatic induction. Further, the surrounding
equipment produces error action. For different interferences, please refer to the
following remedies:
1) Generally the meters, receivers and sensors for measuring and testing have more
weak signals. If they are placed nearby the inverter or together with the inverter in the
same control cabinet, they easily suffer from interference and thus generate error actions.
It is recommended to handle with the following methods: away from the interference
source as far as possible; do not arrange the signal cables with the power cables in
parallel and never bind them together; both the signal cables and power cables shall use
shielded cables and shall be well grounded; install ferrite magnetic ring (with
suppressing frequency of 30 to 1, 000MHz) at the output side of the inverter and wind it
2 to 3 turns; install EMC output filter in more severe conditions.
2) When the interfered equipment and the inverter use the same power supply, it
may cause conduction interference. If the above methods cannot remove the
interference, it shall install EMC filter between the inverter and the power supply (refer
to Section 6.3.6 for the selection operation);
3) The surrounding equipment shall be separately grounded, which can avoid the
interference caused by the leakage current of the inverter's grounding wire when
common grounding mode is adopted.

6-3-5.Remedies for leakage current

There are two forms of leakage current when using the inverter. One is leakage
Chapter 6 EMC (Electromagnetic Compatibility)
183