VLT
®
4000 VT
Installation
■
High voltage test
A high voltage test can be carried out by short-circuiting
terminals U, V, W, L
1
, L
2
and L
3
and energizing
by max. 2.5 kV DC for one second between
this short-circuit and the chassis.
NOTE
The RFI switch must be closed (position ON)
when high voltage tests are carried out . The
line and motor connection must be interrupted
in the case of high voltage tests of the total installation
if the leakage currents are too high.
■
Heat emission from VLT 4000 VT
The tables in
General technical data
show the power
loss P
ϕ
(W) from VLT 4000 VT. The maximum cooling air
temperature t
IN, MAX
is 40° at 100% load (of rated value).
■
Ventilation of integrated VLT 4000 VT
The quantity of air required for cooling AFD
can be calculated as follows:
1. Add up the values of P for all the AFDs to be
integrated in the same panel.
The highest cooling air temperature (t
IN
) present
must be lower than t
IN, MAX
(40°C).
The day/night average must be 5°C lower.
The outlet temperature of the cooling air must
not exceed: t
OUT, MAX
(45° C).
2. Calculate the permissible difference between
the temperature of the cooling air (t
IN
) and
its outlet temperature (t
OUT
):
t= 45° C-t
IN
.
3. Calculate the required
Insert
t in Kelvin
The outlet from the ventilation must be placed
above the highest-mounted AFD.
Allowance must be made for the pressure loss
across the filters and for the fact that the pressure
is going to drop as the filters are choked.
MG.40.A7.22 - VLT is a registered Danfoss trademark
37
