11
VLT
®
3500 HVAC
MG.35.B1.02 – VLT is a registered Danfoss trademark
Section 1Section 1Section 1Section 1Section 1
Section 2Section 2Section 2Section 2Section 2
Section 3Section 3Section 3Section 3Section 3
Section 4Section 4Section 4Section 4Section 4
The drawing shows the base and its dimensions.
VLT
type
3625-3700
3750-3800
A [mm]
127
127
B [mm]
495
495
C [mm]
361
495
D [mm]
4 x 12.7
4 x 12.7
b [mm]
445
445
c [mm]
310
445
The bases for VLT 3500 HVAC and options have been
updated to fit VLT 3625-3800 with its detachable
bottom plate. Please note that the ventilation slits
have been replaced by two apertures in the sides. If a
base for the mounting cabinet and RFI in IP 54 en-
closure are also used, make sure that the ventilation
apertures match.
A base of the new design can be used with previous
versions of VLT 3625-3800 HVAC; however, a base
with the previous design must never be used for
frequency converters with a detachable bottom plate.
Front door VLT 3542-3562 (230V), 3575-3800
HVAC
The front door for VLT 3542-3562 (230V) and 3575-
3800 HVAC is hinged on the left-hand side.
The table below gives the door radius and the neces-
sary distance from the mounting surface for the door
to be able to open freely:
VLT type 3575* 3600 3625 3650 3700 3750 3800
C [mm]
846
846
894
894
894
1008 1008
R [mm]
505
505
513
513
513
513
513
■
*
Dimensions for VLT 3575 also apply to VLT 3542-
3562, 230 volts.
2.3 Mechanical installation
■
∆
t
Σ
P
ϕ
x 3.1
Example
Total power loss and total quantity of air required at
100% load for eight VLT 3508 HVAC (380 volts)
integrated in the same panel.
•
The cooling air temperature (t
IN
) = 40° C and the
max. cooling air outlet temperature (t
OUT, MAX
) = 45° C.
P
Φ
= 280 W and t
IN, MAX
= 40° C.
1.
Σ
P
Φ
= 8xP
Φ
(
W) = t
IN, MAX
= 2240 W.
2.
∆
t = 45°C-t
IN
= 45°C-40°C= 5°K.
3. Quantity of air (at 40°C) =
■
■
2240 x 3.1
= 1388 m
3
/h
5
Heat emission from VLT 3500 HVAC
The table on page 5-7 show the power loss P
φ
(
W)
from VLT 3500 HVAC. The maximum cooling air
temperature t
IN, MAX
is 40° at 100% load (of rated value).
Ventilation of integrated VLT 3500 HVAC
The quantity of air required for cooling frequency
converters can be calculated as follows:
1. Add up the values of P
Φ
for all the frequency
converters 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
(VDE 160).
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
quantity of air =
m
3
/h
Insert
∆
t in Kelvin
The outlet from the ventilation must be placed
above the highest-mounted frequency converter.
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.
