VLT
®
6000 HVAC Series
■
Derating for air pressure
Below 1000 m altitude no derating is necessary.
Above 1000 m the ambient temperature (T
AMB
) or
max. output current (I
VLT,MAX
) must be derated in
accordance with the diagram below:
1. Derating of output current versus altitude
at T
AMB
= max. 45°C
2. Derating of max. T
AMB
versus altitude at
100% output current.
■
Derating for running at low speed
When a centrifugal pump or a fan is controlled by a VLT
6000 HVAC frequency converter, it is not necessary
to reduce the output current at low speed because
the load characterstic of the centrifugal pumps/fans,
automatically ensures the necessary reduction.
■
Derating for long motor cables or cables
with larger cross-section
VLT 6000 HVAC has been tested using 300
m unscreened/unarmoured cable and 150 m
screened/armoured cable.
VLT 6000 HVAC has been designed to work using a
motor cable with a rated cross-section. If a cable with
a larger cross-section is to be used, it is recommended
to reduce the output current by 5% for every step
the cross-section is increased. (Increased cable
cross-section leads to increased capacity to earth,
and thus an increased earth leakage current).
■
Derating for high switching frequency
A higher switching frequency (to be set in parameter
407,
Switching frequency
) leads to higher losses in
the electronics of the frequency converter.
VLT 6000 HVAC has a pulse pattern in which
it is possible to set the switching frequency
from 3.0- 10.0/14.0 kHz.
The frequency converter will automatically derate
the rated output current I
VLT,N,
when the switching
frequency exceeds 4.5 kHz.
In both cases, the reduction is carried out
linearly, down to 60% of I
VLT,N
.
The table gives the min., max. and factory-set
switching frequencies for VLT 6000 HVAC units.
Switching frequency [kHz]
Min.
Max.
Fact.
VLT 6002-6005, 200 V
3.0
10.0
4.5
VLT 6006-6032, 200 V
3.0
14.0
4.5
VLT 6042-6062, 200 V
3.0
4.5
4.5
VLT 6002-6011, 460 V
3.0
10.0
4.5
VLT 6016-6062, 460 V
3.0
14.0
4.5
VLT 6072-6122, 460 V
3.0
4.5
4.5
VLT 6152-6352, 460 V
3.0
4.5
4.5
VLT 6402-6602, 460 V
1.5
3.0
3.0
VLT 6002-6011, 600 V
4.5
7.0
4.5
VLT 6016-6032, 600 V
3.0
14.0
4.5
VLT 6042-6062, 600 V
3.0
10.0
4.5
VLT 6072, 600 V
3.0
4.5
4.5
VLT 6102-6352, 690 V
1.5
2.0
2.0
VLT 6402-6652, 600 V
1.5
1.5
1.5
MG.61.A5.02 - VLT is a registered Danfoss trademark
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