VLT
®
4000 VT
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Motor thermal protection
The electronic thermal relay in UL-approved AFD has
received UL-approval for single motor protection, as
long as parameter 117
Motor thermal protection
has
been set to ETR Trip and parameter 105
Motor current,
I
VLT,N
has been programmed for the rated motor current
(can be read from the motor nameplate).
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Ground connection
Since the leakage currents to ground may be higher
than 3.5 mA, the AFD must always be grounded
in accordance with applicable national and local
regulations. In order to ensure good mechanical
connection of the ground cable, its cable cross-section
must be at least 8 AWG/10 mm
2
. For added security,
an RCD (Residual Current Device) may be installed. This
ensures that the AFD will cut out if the leakage currents
get too high. See RCD Instructions MI.66.AX.02.
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Installation of 24 Volt external DC supply:
Torque: 0.5 - 0.6 Nm
Screw size: M3
No.
Function
35 (-), 36 (+)
24 V external DC supply
24 V external DC supply can be used as low-voltage
supply to the control card and any option cards
installed. This enables full operation of the LCP (incl.
parameter setting) without connection to mains.
Please note that a warning of low voltage will be
given when 24 V DC has been connected; however,
there will be no tripping. If 24 V external DC supply
is connected or switched on at the same time as
the mains supply, a time of min. 200 msec. must
be set in parameter 111,
Start delay
.
A pre-fuse of min. 6 Amp, slow-blow, can be
fitted to protect the external 24 V DC supply.
The power consumption is 15-50 W, depending
on the load on the control card.
NOTE
Use 24 V DC supply of type PELV to ensure
correct galvanic isolation (type PELV) on
the control terminals of the VLT AFD.
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DC bus connection
The DC bus terminal is used for DC back-up,
with the intermediate circuit being supplied
from an external DC source.
Terminal nos.
Nos. 88, 89
Contact Danfoss if you require further information.
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High-voltage relay
The cable for the high-voltage relay must be connected
to terminals 01, 02, 03. The high-voltage relay is
programmed in parameter 323,
Relay 1, output
.
Relay output 1
No. 1
1+3 break, 1+2 make.
Max. 240 V AC, 2 Amp.
Min. 24 V DC, 10 mA or
24 V AC, 100 mA.
Max. cross-section:
4 mm
2
/10 AWG.
Torque:
4.5 - 5 ln lb.
Screw size:
M3
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Control card
All terminals for the control cables are located under
the protective cover of the VLT AFD.
The protective cover (see drawing below) can
be removed by means of a pointed object -
a screwdriver or similar.
MG.40.A7.22 - VLT is a registered Danfoss trademark
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