2 Introduction to VLT HVAC Drive
2.1 Safety
2.1.1 Safety Note
The voltage of the frequency converter is dangerous whenever connected to mains. Incorrect installation of the motor, frequency
converter or fieldbus may cause death, serious personal injury or damage to the equipment. Consequently, the instructions in this
manual, as well as national and local rules and safety regulations, must be complied with.
Safety Regulations
1.
The frequency converter must be disconnected from mains if repair work is to be carried out. Check that the mains supply has been disconnected
and that the necessary time has passed before removing motor and mains plugs.
2.
The [STOP/RESET] key on the LCP of the frequency converter does not disconnect the equipment from mains and is thus not to be used as a
safety switch.
3.
Correct protective earthing of the equipment must be established, the user must be protected against supply voltage, and the motor must be
protected against overload in accordance with applicable national and local regulations.
4.
The earth leakage currents are higher than 3.5 mA.
5.
Protection against motor overload is set by par. 1-90
Motor Thermal Protection
. If this function is desired, set par. 1-90
Motor Thermal Protec-
tion
to data value [ETR trip] (default value) or data value [ETR warning]. Note: The function is initialized at 1.16 x rated motor current and rated
motor frequency. For the North American market: The ETR functions provide class 20 motor overload protection in accordance with NEC.
6.
Do not remove the plugs for the motor and mains supply while the frequency converter is connected to mains. Check that the mains supply has
been disconnected and that the necessary time has passed before removing motor and mains plugs.
7.
Please note that the frequency converter has more voltage inputs than L1, L2 and L3, when load sharing (linking of DC intermediate circuit) and
external 24 V DC have been installed. Check that all voltage inputs have been disconnected and that the necessary time has passed before
commencing repair work.
VLT
®
HVAC Drive Design Guide
2 Introduction to VLT HVAC Drive
MG.11.B9.02 - VLT
®
is a registered Danfoss trademark
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