Before Commencing Repair Work; Special Conditions - Danfoss VLT Instruction Manual

1 Safety
• Make sure the adjustable frequency drive is properly grounded.
• Do not remove AC line input connections, motor connections or other power connections while the adjustable frequency drive is connected to
1
line power.
• Protect users against supply voltage.
• Protect the motor against overloading in accordance with national and local regulations.
• The ground leakage current exceeds 3.5 mA.
• The [OFF] key is not a safety switch. It does not disconnect the adjustable frequency drive from line power.

1.1.4 Before Commencing Repair Work

1. Disconnect the adjustable frequency drive from line power.
2. Disconnect DC bus terminals 88 and 89.
3. Wait at least the time mentioned above in the section General Warning.
4. Remove motor cable

1.1.5 Special conditions

Electrical ratings:
The rating indicated on the nameplate of the adjustable frequency drive is based on a typical 3-phase line power supply within the specified voltage,
current and temperature ranges, which are expected to be used in most applications.
The adjustable frequency drives also support other special applications, which affect the electrical ratings of the adjustable frequency drive.
Special conditions that affect the electrical ratings might be:
• Single phase applications.
• High temperature applications that require derating of the electrical ratings.
• Marine applications with more severe environmental conditions.
Other applications might also affect the electrical ratings.
Consult the relevant sections in this manual and in the
Installation requirements:
The overall electrical safety of the adjustable frequency drive requires special installation considerations regarding:
• Fuses and circuit breakers for overcurrent and short-circuit protection
• Selection of power cables (line power, motor, brake, load sharing and relay)
• Grid configuration (IT,TN, grounded leg, etc.)
• Safety of low-voltage ports (PELV conditions).
Consult the relevant clauses in these instructions and in the
1-2
VLT HVAC Drive Design Guide, MG.11.BX.YY
VLT HVAC Drive Design Guide
for information about the installation requirements.
MG.11.A9.22 - VLT ® is a registered Danfoss trademark
VLT ® HVAC Drive Instruction Manual
for information about the electrical ratings.