Danfoss VLT HVAC - 8.2.6. Automatic adaptations to ensure performance

If the frequency converter is operated at high ambient temperatures, the continuous output cur-
rent should be decreased.
The derating depends on the switching pattern, which can be set to 60 PWM or SFAVM in pa-
rameter 14-00.
A enclosures
60 PWM - Pulse Width Modulation
Illustration 8.1: Derating of I
out
for different T
AMB,
MAX
for enclosure A, using 60 PWM
SFAVM - Stator Frequency Asyncron
Vector Modulation
Illustration 8.2: Derating of I
out
for different T
AMB,
MAX
for enclosure A, using SFAVM
In enclosure A, the length of the motor cable has a relatively high impact on the recommended
derating. Therefore, the recommended derating for an application with max. 10 m motor cable is
also shown.
Illustration 8.3: Derating of I
out
for different T
AMB,
MAX
for enclosure A, using 60 PWM and maximum
10 m motor cable
Illustration 8.4: Derating of I
out
for different T
AMB,
MAX
for enclosure A, using SFAVM and maximum
10 m motor cable
VLT
®
HVAC Drive Operating Instructions 8. Specifications
MG.11.A4.02 - 09.10.06. VLT
®
is a registered Danfoss trademark 139
8