Lenze Inverter EMC - Manual (Page 13)

Arrangement according to EMC requirements
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EDBEMV EN 1.3
6 Arrangement according to EMC requirements
6.1 Specification for shielded cables for arrangement according to
EMC
6.1.1 Motor cable design
z Only use shielded, four-core motor cable (core U, V, W, PE and overall shield).
z Cables with a YCY copper braid have a good shielding effect, cables with SY steel-tape
armour are less suitable (high shield resistance).
z The contact ratio of the braid:
– At least 70% to 80% with overlap angle of 90 °.
z Use low-capacitance cables to reduce the discharge currents.
– The values depend on the cable cross-section.
z The rated voltage of the motor cable for inverter operation amounts to Uo/U= 0.6/1 kV.
z The cables used must comply with the required approvals of the application (e.g. UL).
The EMC safety of the connection for motor temperature monitoring depends on how the shielded
connecting cables are laid.
EMC safety Type of laying Note
Very good Motor cable and PTC/thermal
contact cable are laid separately Ideal laying system with very low interference
injections.
Treat PTC/thermal contact cable like a control cable
Medium Motor cable and PTC/thermal
contact cable are laid together
with separate shields
Laying system is permitted but shows higher
interference injections.
Unfavorable Motor cable and PTC/thermal
contact cable are laid together
with a common shield
High-energy interference injections!
6.1.2 Cable design for DC connection and brake resistor
z These DC cables must be designed like the motor cable.
– Shielding
– Rated voltage
– Approval
z Being relatively short, low-capacitance versions are not necessary.
6.1.3 Control cable design
Control cables must be shielded to minimise interferences.
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