Figure 3.5: Galvanic isolation
The functional galvanic isolation (a and b in drawing) is for the 24 V backup option and for the RS-485 standard bus interface.
Installation at high altitude:
380–500 V, enclosure A, B and C: At altitudes above 6,500 ft [2 km], please contact Danfoss regarding PELV.
380–500 V, enclosure D, E and F: At altitudes above 10,000 ft [3 km], please contact Danfoss regarding PELV.
525–690 V: At altitudes above 6,500 ft [2 km], please contact Danfoss regarding PELV.
Warning:
Touching the electrical parts may be fatal - even after the equipment has been disconnected from line power.
Also make sure that other voltage inputs have been disconnected, such as load sharing (linkage of DC intermediate circuit), as well as
the motor connection for kinetic backup.
Before touching any electrical parts, wait at least the amount of time indicated in the
Safety Precautions
section.
Shorter time is allowed only if indicated on the nameplate for the specific unit.
Leakage Current
The ground leakage current from the adjustable frequency drive exceeds 3.5 mA. To ensure that the ground cable has a good me-
chanical connection to the ground connection (terminal 95), the cable cross-section must be at least 3.9 in
2
[10 mm
2
] or two rated
ground wires terminated separately.
Residual Current Device
This product can cause DC current in the protective conductor. Where a residual current device (RCD) is used for protection in case of
direct or indirect contact, only an RCD of Type B is allowed on the supply side of this product. Otherwise, another protective measure
shall be applied, such as separation from the environment by double or reinforced insulation, or isolation from the supply system by a
transformer. See also RCD Application Note MN.90.GX.02.
Protective grounding of the adjustable frequency drive and the use of RCDs must always follow national and local regulations.
FC 300 Design Guide
3 Introduction to AutomationDrive FC 300
MG.33.BC.22 - VLT
®
is a registered Danfoss trademark
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