Danfoss VLT AutomationDrive FC 300 Instruction Manual page 9

VLT ® AutomationDrive FC 300 Instruction
Manual
Protection Mode
Once a hardware limit on motor current or DC link voltage is exceeded the adjustable frequency drive will enter "protection mode". "Protection mode"
means a change of the PWM modulation strategy and a low switching frequency to minimize losses. This continues 10 sec after the last fault and increases
the reliability and the robustness of the adjustable frequency drive while re-establishing full control of the motor.
In hoist applications, "protection mode" is not usable because the adjustable frequency drive will usually not be able to leave this mode again and therefore
it will extend the time before activating the brake – which is not recommended.
"Protection mode" can be disabled by setting par. 14-26
immediately if one of the hardware limits is exceeded.
NOTE!
It is recommended to disable protection mode in hoisting applications (par. 14-26
2.1.3 General Warning
Warning:
Touching the electrical parts may be fatal - even after the equipment has been disconnected from line power.
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 back-up.
Using VLT AutomationDrive: wait at least 15 minutes.
A 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 0.016 in.
rated ground wires terminated separately.
Residual Current Device
This product can produce D.C. 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 RCD Application Note MN.90.GX.02.
Protective grounding of the VLT AutomationDrive and the use of RCDs must always follow national and local regulations.
NOTE!
For vertical lifting or hoisting applications, ensuring that the load can be stopped in case of an emergency or the malfunction of a single
part (e.g., a contactor) is strongly recommended.
If the adjustable frequency drive is in alarm mode or in an overvoltage situation, the mechanical brake cuts in.
2.1.4 Before Commencing Repair Work
1. Disconnect the adjustable frequency drive from line power.
2. Disconnect DC bus terminals 88 and 89 from load share applications
3. Wait for the discharge of the DC link. See period of time on the warning label.
4. Remove motor cable
Trip Delay at Inverter Fault
to zero which means that the adjustable frequency drive will trip
®
MG.33.AG.22 - VLT is a registered Danfoss trademark
2 Safety Instructions and General Warning
Trip Delay at Inverter Fault = 0)
2 [10 mm
2
2 ] or 2 times
2-3