Avoid Unintended Start; Before Commencing Repair Work - Danfoss VLT Micro Drive FC 51 Series Programming Manual

1. Safety
Leakage Current
The earth leakage current from the frequency converter exceeds 3.5 mA. According to IEC 61800-5-1 a reinforced Protective Earth
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connection must be ensured by means of a min. 10mm² Cu or an addtional PE wire - with the same cable cross section as the Mains
wiring - must be terminated separately.
Residual Current Device
This product can cause a DC current in the protective conductor. Where a residual current device (RCD) is used for extra protection,
only an RCD of Type B (time delayed) shall be used on the supply side of this product. See also Danfoss Application Note on RCD, MN.
90.GX.YY.
Protective earthing of the frequency converter and the use of RCDs must always follow national and local regulations.
Motor overload protection is possible by setting Parameter 1-90 Motor thermal protection to the value ETR trip. For the North American
market: ETR functions provide class 20 motor overload protection, in accordance with NEC.
Installation in high altitudes:
For altitudes above 2 km, please contact Danfoss regarding PELV.
1.1.5. IT Mains
IT Mains
Installation on isolated mains source, i.e. IT mains.
Max. supply voltage allowed when connected to mains: 440 V.
As an option, Danfoss offers line filters for improved harmonics performance.

1.1.6. Avoid unintended Start

While the frequency converter is connected to mains, the motor can be started/stopped using digital commands, bus commands, references or via the
Local Control Panel.
• Disconnect the frequency converter from mains whenever personal safety considerations make it necessary to avoid unintended start of any
motors.
• To avoid unintended start, always activate the [OFF] key before changing parameters.
1.1.7. Disposal Instruction

1.1.8. Before Commencing Repair Work

1. Disconnect FC 51 from mains (and external DC supply, if present.)
2. Wait for 4 minutes for discharge of the DC-link.
3. Disconnect DC bus terminals and brake terminals (if present)
4. Remove motor cable
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Equipment containing electrical components must not be disposed of together with domestic waste.
It must be separately collected with electrical and electronic waste according to local and currently valid leg-
islation.
MG.02.C4.02 - VLT is a registered Danfoss trademark
VLT Micro Drive FC 51