This will activate the PumpDrive's protective equipment and PumpDrive will be
switched off. The following motor connection cables are recommended depending
on the power range:
Table 16: Length of motor connection cable
Power range
[kW]
Maximum cable length
[m]
Stray capacitance
[nF]
≤ 7.5 (class B)
5
≤ 5
> 7.5 (class A1)
50
≤ 5
If longer connection cables than those listed above are required or the connection
cable's stray capacitance value exceeds the above values, we recommend installing a
suitable output filter between PumpDrive and the motor to be controlled. These
filters reduce the voltage ramp-up time of the PumpDrive output voltages and limit
their peaks.
5.4.2.2
Electrical protection equipment
Provide three fast-acting fuses in the mains power supply line to PumpDrive. Design
the fuse size in line with the nominal mains current of PumpDrive.
If fixed connections and appropriate supplementary earthing are used (cf. DIN
VDE 0160), RCDs are not mandatory for frequency inverters. If residual current
devices (RCDs) are used, three-phase frequency inverters in accordance with DIN VDE
0160 must be connected via universal AC/DC sensitive RCDs, as potential direct-
current components may cause standard AC sensitive RCDs to either fail to respond
or respond erroneously.
Table 17: RCD (residual current device) rated current
Size
RCD (residual current device) rated current
[mA]
A and B
150
C and D
300
29)
If you use a long shielded cable for the mains/motor connection, the residual-current
monitoring device may be triggered by the discharge current that flows to earth
(triggered by the carrier frequency). Remedies: Replace the RCD (residual-current
device) or lower the response limit.
Separate motor protection is not required because PumpDrive has its own safety
devices (e.g. electronic overcurrent trip). Set any motor protection switches fitted to a
minimum of 1.4 times the nominal (mains) current.
5.4.2.3
Information on electromagnetic compatibility
Electromagnetic interference from other electrical devices can affect PumpDrive.
Interference can also be generated by PumpDrive itself, however.
The interference emitted by PumpDrive is typically conducted through the motor
connection cables. The following measures are proposed for RFI suppression:
▪
Shielded motor connection cables for line lengths > 70 cm
(especially recommended for PumpDrives with low power ratings)
▪
Metal cable ducts made from a single piece with a minimum coverage of 80 % (if
shielded connection cables cannot be used)
For more effective shielding, install PumpDrive in a metal cabinet.
When installing the power components in the control cabinet, make sure they are
not too close to other devices (control and monitoring devices).
Maintain a minimum distance of 0.3 metres between the cabling and power
components as well as other cabling in the control cabinet.
Use different earth bus bars for the control cable and power/motor connection cable.
Output filter
RCD (residual current
device)
Motor protection switch
Installation at site/
Environment
Connect cables
29)
Use a permanent, fixed installation and reinforced protective earthing on the motor to accommodate the higher discharge
current (> 3.5 mA).
5 Installation at Site
PumpDrive
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