SSD 605C Product Manual - Ertification For The

Certification for the Inverter  

12-1

605C Frequency Inverter

12 

C

ERTIFICATION FOR THE 

I

NVERTER

Requirements for EMC Compliance

All Variable Speed Drives (VSDs) potentially produce electrical emissions which are radiated

into the environment and conducted back into the ac supply. VSDs are inherently immune to

any additional external electrical noise. The following information is provided to maximise the

Electro Magnetic Compatibility (EMC) of VSDs and systems in their intended operating

environment, by minimising their emissions and maximising their immunity.

Minimising Radiated Emissions

EN55011/EN55022 radiated emission measurements are made between 30MHz and 1GHz in

the far field at a distance of 10 to 30 metres. Limits lower than 30MHz or in close proximity are

not specified. Emissions from individual components tend to be additive.

•  Use a screened/armoured cable between VSD/cubicle and motor containing the motor

protective earth (PE) connection. It should  have a 360° screen termination. Earth screen at

both ends connecting to the motor frame and cubicle (or gland box if wall mounted).

Maintain the screen integrity using 360° terminations.

Note:  Some hazardous area installations may preclude direct earthing at both ends of the

screen, in this case earth one end via a 1

µ

F 50Vac capacitor, and the other as normal.

•  Keep unshielded cable as short as possible inside the cubicle.

•  Always maintain the integrity of the shield.

•  If the cable is interrupted to insert contactors etc., re-connect the screen using the shortest

possible route.

•  Keep the length of screen stripped-back as short as possible when making screen

connections.

•  Ideally use 360° screen terminations using cable glands or `U’ clips on power screen rails.

If a shielded cable is not available, lay unshielded motor cables in a metal conduit which will act

as a shield. The conduit must be continuous with a direct electrical contact to the VSD and

motor housing. If links are necessary, use braid with a minimum cross sectional area of 10mm

2

.

Note:  Some motor gland boxes and conduit glands are made of plastic, if this is the case, then

braid must be connected between the screen and the chassis. In addition at the motor

end, ensure that the screen is electrically connected to the motor frame since some

terminal boxes are insulated from the frame by gasket/paint.

Earthing Requirements

IMPORTANT:  Protective earthing always takes precedence over EMC earthing.

Protective Earth (PE) Connections

Note:  In accordance with installations to EN60204, only one protective earth conductor is

permitted at each protective earth terminal contacting point.

Local wiring regulations may require the protective earth connection of the motor to be

connected locally, i.e. not as specified in these instructions. This will not cause shielding

problems because of the relatively high RF impedance of the local earth connection.

EMC Earth Connections

For compliance with EMC requirements, we recommend that the “0V/signal ground” is

separately earthed. When a number of units are used in a system, these terminals should be

connected together at a single, local earthing point.