GB - 38
Annex
A.3 Calculation of the motor voltage
The motor voltage for dimensioning of the drive is depending on the used components. The
mains voltage reduces according to the following table:
Mains choke Uk 4 % Example:
Inverter open loop 4 % Closed loop inverter with mains- and motor choke at
non-rigid supply system:
400 V mains voltage - 15 % = 340 V motor voltage
Inverter closed loop 8 %
Motor choke Uk 1 %
Non-rigid supply sys-
tem
2 %
A.4 Maintenance
Allworkmayonlybedonebyqualiedpersonnel.Thesecuritymustbeensuredasfollows:
• Disconnect power supply at MCCB
• Secure against restarting
• Await discharge time of capacitors (if necessary controlling by measurement at „+PA“ and
„-“, respectively “++“ and „--“)
• Ensure loss of voltage by measurement
In order to avoid premature ageing and avoidable malfunctions, the measures mentioned
below must be carried out in the appropriate cycle.
Cycle Function
Constant
Pay attention to unusual noises of the motor (e.g. vibrations) as well as of the
frequency inverter (e.g. fan).
Pay attention to unusual smells of the motor or frequency inverter (e.g. evap-
oration of capacitor electrolyte, braise of the motor winding)
Monthly
Check unit for loose screws and plugs and if necessary tighten up.
Clean frequency inverter from dirt and dust deposits. Pay attention especially
tocoolingnsandprotectivegridofthefans.
Examineandcleanextractedairlterandcoolingairlterofthecontrolcabi-
net.
Examine function of the fans of the KEB COMBIVERT. The fans must be re-
placed in case of audible vibrations or squeak.
Annual
Check the connecting ducts for corrosion and change it if necessary for units
with water cooling.
A.5 Storage
The DC link of the KEB COMBIVERT is equipped with electrolytic capacitors. If the electrolyt-
ic aluminium capacitors are stored de-energized, the internal oxide layer is removed slowly.
Due to the leakage current the oxide layer is unrenewed. If the capacitor starts running with
rated voltage there is a high leakage current which can destroy the capacitor.
In order to avoid defectives, the KEB COMBIVERT must be started up depending on the
storageperiodinaccordancewiththefollowingspecication: