5–4

Component Descriptions

Zero-phaseReactor (RFNoise Filter)EMI Filter

Motor Control

Accessories

 

 

Ferrite CoreRF Noise Filter (Capacitive)DC Link Choke

Electrical noise interference may occur on nearby equipment such as a radio receiver. The zero-phase reactor helps reduce radiated noise from the inverter wiring. It can be used on the input or output side of the inverter. The example zero-phase reactor shown to the right comes with a mounting bracket. The wiring must go through the opening to reduce the RF component of the electrical noise. Loop the wires three times (four turns) to attain the full RF filtering

effect. For larger wire sizes, place

multiple zero-phase reactors (up toZCL–xfour) side-by-side for a greater filtering

effect.

The EMI filter reduces the conducted noise on the power supply wiring generated by the inverter. Connect the EMI filter to the inverter primary (input side). The NF–CEH–x series filter is required for compliance to the EMC Class A directive (Europe) and C-TICK (Austra- lia). See “CE–EMC Installation Guidelines” on page D–2.

WARNING: The EMI filter has high internal leakage current from power wiring to the chassis. Therefore, connect the chassis ground of the EMI filter before making the power connections to avoid danger of shock or injury.

NF–CEHxx

To meet EMC Class B limit an optional ferrite core (FC–Hx) must be inserted between the NF–CEHx filter (above) and the inverter.

This capacitive filter reduces radiated noise from the main power wires in the inverter input side. This filter is not for achieving CE compliance and is applicable only to the input side only of the inverter. It comes in two versions—for 200V class inverters or 400V class inverters. Please refer to the documentation that comes with the radio noise filter for installation instruc- tions.

The DC choke (reactor) suppresses harmonics generated by the inverter. It attenuates the high- frequency components on the inverter’s internal DC bus (link). However, note that it does not protect the diode rectifiers in the inverter input circuit.