ZIEHL-ABEGG MAXvent FV31 Series, Assembly Instructions Manual, Page: 21 / 32

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If the cable shield cannot be contacted or not contacted suf fi ciently due to special
framework conditions, use a separate high-frequency equipotential bonding conduc-
tor between the motor housing and the protective earth bar of the inverter.
– Install the separate high-frequency equipotential bonding conductor using braided
fl at copper strips or high-frequency stranded conductors. Solid copper lines are not
suitable for high-frequency earthing due to the current displacement effect.
•
Use suitable common mode fi lters at the inverter output.
•
Limit the voltage increase by using suitable output fi lters (du/dt fi lters).
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We recommend the use of all-pole sinusoidal fi lters.
•
When using all-pole sinusoidal fi lters, screened motor leads, metal terminal boxes
and a second earth connection to the motor can be omitted.
•
General recommendation: Continuous operation of the fan / motor below 15 %
of the nominal speed is not economically and technically reasonable.
5.4 Motor protection
The thermal motor protection is to be implemented depending on the motor design,
observing the motor manufacturer
’ s instructions.
•
For a motor with no temperature monitor in the winding, a motor protection switch is
required.
•
For a motor with “ TP ” temperature sensors (PTC thermistor) a PTC thermistor relay is
required, e.g. ZIEHL-ABEGG type U-EK230E with disconnection via a contactor.
On the design with PTC thermistor, observe the max. permitted test voltage of 2.5 V.
•
On a motor with KTY or PT100 temperature sensors, a suitable temperature monitor-
ing unit is required.
•
On a motor with “ TB ” thermostatic switches, a suitable motor contactor is required,
e.g. ZIEHL-ABEGG type STDT16/25 or AWE/SK with disconnection via a contactor.
Caution! Thermostatic switches switch on again automatically after cooling. The
constructor of the plant must ensure that the fan does not start up automatically, or
that an automatic start-up does not result in any hazard. ZIEHL-ABEGG motor
contactors prevent an automatic restart after the drive has cooled.
Assembly instructions MAXvent Electrical installation
L-BAL-F054-GB 2018 Index 005 Part.-No. 00501414-GB
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