2 Operator Interface and Adjustable Frequency
Drive Control
2.1 Introduction
Adjustable frequency drives are designed with self-diagnostic circuitry to isolate fault conditions
and activate display messages which greatly simplify troubleshooting and service. The operating
status of the adjustable frequency drive is displayed in real-time. Virtually every command given
to the adjustable frequency drive results in some indication on the local control panel LCP display.
Fault logs are maintained within the adjustable frequency drive for fault history.
The adjustable frequency drive monitors supply and output voltages along with the operational
condition of the motor and load. When the adjustable frequency drive issues a warning or an
alarm, it cannot be assumed that the fault lies within the adjustable frequency drive itself. In fact,
for most service calls, the fault condition will be found outside of the adjustable frequency drive.
Most of the warnings and alarms that the adjustable frequency drive displays are generated by
response to faults outside of the adjustable frequency drive. This service manual provides tech-
niques and test procedures to help isolate a fault condition whether in the adjustable frequency
drive or elsewhere.
Familiarity with the information provided on the display is important. Additional diagnostic data
can be accessed easily through the LCP.
2.2 User Interface
2.2.1 How to Operate the Graphic Local Control Panel (LCP)
The LCP is divided into four functional groups:
1.
Graphical display with status lines.
2.
Menu keys and indicator lights (LEDs) - selecting mode, changing parameters and
switching between display functions.
3.
Navigation keys and indicator lights (LEDs).
4.
Operation keys and indicator lights (LEDs).
Graphical display:
The LCD display is back-lit with a total of 6 alpha-numeric lines. All data is displayed on the LCP
which can show up to five operating variables while in [Status] mode.
High Power Service Manual for VLT
®
FC Series
Adjustable Frequency Drives
2 Operator Interface and Adjustable Frequen-
cy Drive Control
MG.90.L1.22 - VLT
®
is a registered Danfoss trademark
2-1
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Summary of Contents for VLT HVAC FC 100
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