Test Procedures; Introduction - Danfoss VLT HVAC Drive FC 100 Service Manual

High Power Service Manual for VLT
Adjustable Frequency Drives

6 Test Procedures

6.1 Introduction

This section contains detailed procedures for testing adjustable frequency drive. Previous sections
of this manual provide symptoms, alarms and other conditions which require additional test pro-
cedures to further diagnose the adjustable frequency drive. The results of these tests indicate the
appropriate repair actions. Again, because the adjustable frequency drive monitors input and out-
put signals, motor conditions, AC and DC power and other functions, the source of fault conditions
may exist outside of the adjustable frequency drive itself. Testing described here will isolate many
of these conditions as well. Sections 7 and 8, Disassembly and Assembly Instructions, describes
detailed procedures for removing and replacing adjustable frequency drive components, as re-
quired (D- or E-sized adjustable frequency drives, respectively).
Adjustable frequency drive testing is divided into
or After Repair Drive Tests
frequency drive. Most adjustable frequency drive problems can be diagnosed simply with these
tests. Static tests are performed with little or no disassembly. The purpose of static testing is to
check for shorted power components. Perform these tests on any unit suspected of containing
faulty power components prior to applying power.
Dynamic tests are performed with power applied to the adjustable frequency drive. Dynamic test-
ing traces signal circuitry to isolate faulty components.
Both D-frame and E-frame size adjustable frequency drives are covered here. Differences in the
procedures are noted, as required. However, the Soft Charge and Rectifier Circuit Test, Soft
Charge Rectifier Test, and Fan Continuity Test sections are independent for D-frame and E-frame
adjustable frequency drives.
Replace any defective component and retest the adjustable frequency drive with the new com-
ponent before applying power to the adjustable frequency drive as described in
After Repair Drive Tests
®
FC Series
Touching electrical parts of the adjustable frequency drive may be fatal even after
equipment has been disconnected from AC power. Wait 20 minutes for D-frame sizes
or 40 minutes for E-frame sizes after power has been removed before touching any
internal components to ensure that capacitors have fully discharged. See label on
front of adjustable frequency drive door for specific discharge time.
. Static tests are conducted without power applied to the adjustable
For dynamic test procedures, main input power is required. All devices and power
supplies connected to line power are energized at rated voltage. Use extreme cau-
tion when conducting tests on a powered adjustable frequency drive. Contact with
powered components could result in electrical shock and personal injury.
.
MG.90.L1.22 - VLT ® is a registered Danfoss trademark
Static Tests Dynamic Tests
, , and
6 Test Procedures
6
Initial Start Up
Initial Start Up or
6-1