Lenze 8400 BaseLine Manual - Manual (Page 48)

Electrical installation
Important notes
Device protection
6

48 EDS84ABD302 EN 4.0
6.1.2 Device protection
ƒ In case of condensation, do not connect the controller to the mains voltage before
the moisture has evaporated completely.
ƒ
The controller must be protected by external fuses.
6.1.3 Maximum motor cable length
ƒ
The motor cable must be as short as possible for having a positive effect on the drive
behaviour.
ƒ
For group drives (several motors connected to one drive controller) the resulting
cable length l
res
is the crucial factor:
I
res
[m] = (l
1
+ l
2
+ l
3
... + l
i
) ⋅ i  l
x
Length of the individual motor cable
l
res
Resulting length of the motor cable
i Number of the individual motor cables
ƒ At rated mains voltage and a switching frequency of 4 kHz and without additional
output filters, the maximum permissible length of the motor cable is as follows:
– 50 m shielded
– 100 m unshielded

Note!
For compliance with EMC regulations, the permissible cable lengths must be
reduced.
6.1.4 Motor protection
ƒ Extensive protection against overload:
– Through overcurrent relay or temperature monitoring.
– We recommend to use thermostats for motor temperature monitoring.
– Thermostat contacts can be used to activate a digital input DI1 ... DI4 for ”external
fault” alarm.
ƒ Only use motors which have a suitable insulation for the inverter operation:
– Insulation resistance: min. û = 1.5 kV, min. du/dt = 5 kV/μs
– When using motors with an unknown insulation resistance, please contact your
motor supplier.
6.1.5 Interaction with compensation equipment
ƒ Controllers only consume very little reactive power of the fundamental wave from
the AC supply mains. Therefore a compensation is not required.
ƒ If the controllers are connected to a supply system with compensation equipment,
this equipment must be used with chokes.
– For this, contact the supplier of the compensation equipment.