VARIABLE FREQUENCY DRIVE
LIFE CYCLE EXTENSION PROGRAM
THE PROBLEM
An end user experiences a variable frequency drive, VFD, failure in
the middle of the night. The operator quickly replaces the
damaged VFD with an emergency VFD replacement unit they had
purchased more than 8 - 12 months ago. Unfortunately, the
capacitors in the VFD replacement unit catastrophically fail when
power is restored, shutting down the plant.
Unfortunate events like this most likely occur when the VFD is out
of warranty.
This rupture can be very dramatic and destructive. Not only is the
boiling liquid and gas hot, it is also corrosive and will damage any
components covered by the solution.
The dielectric oxide-insulating layer is created during manufacture.
However, it will deteriorate in the absence of a sufficient
rejuvenating voltage, and eventually the capacitor will fail if voltage
is not applied. Maintaining the integrity of the dielectric requires
the steady application of power.
THE ARGO SOLUTION
Contact Argo International about the Argo International VFD Life
Cycle Extension Program. Argo ‘reforms’ the capacitors in
variable frequency drives, applying the rated voltage for a period
of 1 to 5 hours, depending on the condition of the capacitor, and
allowing for a resting period, thereby helping to rebuild the oxide
layer.
The Argo International VFD Life Cycle Extension Program:
Recieving
Inspection
Repair and reform of all capacitors - board caps and bus
capacitors
Testing - Operational Test1
Quality Inspection and Date Code ID
Shipment
WHAT HAPPENED?
ML-E011-R0 01/14
Should the drive not operate, Argo International will evaluate the VFD for free and
quote the repair.
1
The capacitor works by storing
a DC charge between the two
plates. One of the plates has
an insulating oxide layer that is
created and maintained when
the capacitor is charged up. It
is this insulating oxide layer (called a dielectric) that is crucial to
proper capacitor operation. If the dielectric was not present, the
capacitor would short circuit and draw large amounts of current.
When large amounts of current flow into the capacitor, it causes
the electrolyte solution to boil and turn into a gas. Once turned
into a gas, pressure builds rapidly until, hopefully, the safety vent
plug releases pressure.
Argo International recommends the VFD Life Cycle Extension
Program to be performed every 8 -12 months for each stored VFD
Drive to insure all components are fully functional.
CONTACT US
Argo International Texas - Houston
302 W 38th Street, Houston, TX 77018
Sales Office
www.argointl.com
P 1(800) 231 6305 • F (713) 697 6208
© 2014 Argo International. All rights reserved.
Printed in the U.S.A.