2.1.4 Before commencing repair work
1. Disconnect the frequency converter from mains
2. Disconnect DC bus terminals 88 and 89
3. Wait at least the time mentioned in section General Warning above
4. Remove motor cable
2.1.5 Special conditions
Electrical ratings:
The rating indicated on the nameplate of the frequency converter is based on a typical 3-phase mains power supply, within the specified voltage, current
and temperature range, which is expected to be used in most applications.
The frequency converters also support other special applications, which affect the electrical ratings of the frequency converter.
Special conditions which affect the electrical ratings might be:
• Single phase applications
• High temperature applications which require de-rating 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
VLT HVAC Drive Design Guide, MG.11.BX.YY
for information about the electrical ratings.
Installation requirements:
The overall electrical safety of the frequency converter requires special installation considerations regarding:
• Fuses and circuit breakers for over-current and short-circuit protection
• Selection of power cables (mains, motor, brake, loadsharing and relay)
• Grid configuration (grounded delta transformer leg, IT,TN, etc.)
• Safety of low-voltage ports (PELV conditions).
Consult the relevant clauses in these instructions and in the
VLT HVAC Drive Design Guide
for information about the installation requirements.
2.1.6 Installation at high altitudes (PELV)
Hazardous Voltage!
By altitudes above 2 km, please contact Danfoss regarding PELV.
Avoid un-intended start
While the frequency converter is connected to mains, the motor can be started/stopped using digital commands, bus commands,
references or via the LCP.
• Disconnect the frequency converter from mains whenever personal safety considerations make it necessary to avoid unin-
tended start.
• To avoid unintended start, always activate the [OFF] key before changing parameters.
• Unless terminal 37 is turned off, an electronic fault, temporary overload, a fault in the mains supply, or lost motor connection
may cause a stopped motor to start.
Failure to follow recommendations could result in death or serious injury.
VLT
®
HVAC Drive Operating Instructions 2 Safety
MG.11.AB.02 - VLT
®
is a registered Danfoss trademark 13
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