Calculation Of The Motor Voltage; Maintenance; Storage - KEB COMBIVERT F5 Series Instruction Manual

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
Inverter open loop
Inverter closed loop
Motor choke Uk
Non-rigid supply sys-
tem
A.4

Maintenance

All work may only be done by qualified personnel. The security must be ensured as follows:
• 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
Constant
Monthly
Annual
A.5

Storage

The DC link of the KEB COMBIVERT is equipped with electrolytic capacitors. If the electro-
lytic 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 sto-
rage period in accordance with the following specification:
Storage period < 1 year
• Start-up without special measures
4 %
4 %
8 %
1 %
2 %
Function
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. evapo-
ration of capacitor electrolyte, braise of the motor winding)
Check unit for loose screws and plugs and if necessary tighten up.
Clean frequency inverter from dirt and dust deposits. Pay attention especially
to cooling fins and protective grid of the fans.
Examine and clean extracted air filter and cooling air filter of the control cabi-
net.
Examine function of the fans of the KEB COMBIVERT. The fans must be repla-
ced in case of audible vibrations or squeak.
Check the connecting ducts for corrosion and change it if necessary for units
with water cooling.
Example:
Closed loop inverter with mains- and motor choke at
non-rigid supply system:
400 V mains voltage - 15 % = 340 V motor voltage
Annex
further on next side
GB - 33