2 Safety
2.1.1 Safety Note
WARNING
The voltage of the adjustable frequency drive is dangerous
whenever connected to line power. Incorrect installation of
the motor, adjustable frequency drive or serial communi-
cation bus may cause damage to the equipment, serious
personal injury or death. Consequently, the instructions in
this manual, as well as national and local rules and safety
regulations, must be complied with.
Safety Regulations
1. The adjustable frequency drive must be discon-
nected from line power if repair work is to be
carried out. Make sure that the line power supply
has been disconnected and that the necessary
time has passed before removing motor and line
power plugs.
2. The [Off/Reset] key on the LCP of the adjustable
frequency drive does not disconnect the
equipment from line power and is therefore not
to be used as a safety switch.
3. Correct protective grounding 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 ground leakage currents are higher than 3.5
mA.
5.
Protection against motor overload is set by
1-90 Motor Thermal Protection. If this function is
desired, set 1-90 Motor Thermal Protection 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. Note that the adjustable frequency drive has
voltage inputs other than L1, L2 and L3, when
load sharing (linking of DC intermediate circuit)
and external 24 V DC have been installed. Make
sure that all voltage inputs have been discon-
nected and that the necessary time has passed
before commencing repair work.
Installation at High Altitudes
WARNING
At altitudes above 10,000 feet [3 km], please contact
Danfoss regarding PELV.
Warning against Unintended Start
1. The motor can be brought to a stop by means of digital
commands, bus commands, references or a local stop,
while the adjustable frequency drive is connected to line
power. If personal safety considerations make it necessary
to ensure that no unintended start occurs, these stop
functions are not sufficient.
2. While parameters are being changed, the motor may
start. Consequently, the stop key [Reset] must always be
activated; after which data can be modified.
3. A motor that has been stopped may start if faults occur
in the electronics of the adjustable frequency drive, or if a
temporary overload or a fault in the line power or the
motor connection ceases.
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 external 24 V DC, load sharing
(linkage of DC intermediate circuit), as well as the motor
connection for kinetic backup.
2.1.2
General Warning
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, (linkage of DC intermediate circuit), as well
as the motor connection for kinetic backup.
Before touching any potentially live parts of the adjustable
frequency drive, wait at least as follows:
380–480 V, 175–275 hp [132–200 kW], wait at least 20
minutes.
380–480 V, 350–850 hp [250–630 kW], wait at least 40
minutes.
Shorter time is allowed only if indicated on the nameplate
for the specific unit. Be aware that there may be high
voltage on the DC links even when the control card LEDs
are turned off. A red LED is mounted on a circuit board
inside both the adjustable frequency drive and the active
filter to indicate the DC bus voltages. The red LED will stay
lit until the DC link is 50 V DC or lower.
Safety VLT Automation Low Harmonic Drive -AAF006 Instruction Manual
6 MG37A122 - VLT
®
is a registered Danfoss trademark
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