Danfoss VLT HVAC Drive Instruction Manual page 67

VLT ® HVAC Drive Instruction Manual
3-42
Value:
1 - 3,600 s
Function:
Enter the ramp-down time, i.e., the decelera-
tion time from the rated motor speed n
(par. 1-25) to 0 RPM. Choose a ramp-down
time so that no overvoltage arises in the in-
verter due to regenerative operation of the
motor, and so that the generated current does
not exceed the current limit set in par. 4-18.
See ramp-up time in par. 3-41.
par
.3 − 42 =
4-11
Value:
0 - 60,000 RPM
Function:
Enter the minimum limit for motor speed. The
motor speed low limit can be set to corre-
spond to the manufacturer's recommended
minimum motor speed. The motor speed low
limit must not exceed the setting in par. 4-13
Motor Speed High Limit [RPM]
4-12
Value:
0 - 1,000 Hz
Function:
Enter the minimum limit for motor speed. The
motor speed low limit can be set to corre-
spond to the minimum output frequency of
the motor shaft. The motor speed low limit
must not exceed the setting in par. 4-14
Speed High Limit [Hz]
4-13
Value:
0 - 60,000 RPM
Ramp 1 Ramp-down Time
t n par
× .1 − 25
dec norm
ref rpm
Δ
Motor Speed Low Limit [RPM]
Size related
.
Motor Speed Low Limit [Hz]
Size related
Motor
.
Motor Speed High Limit
[RPM]
Size related
MG.11.A4.22 - VLT ® is a registered Danfoss trademark
6. How to program the adjustable frequency
Function:
Enter the maximum limit for motor speed. The
motor speed high limit can be set to corre-
3 s
spond to the manufacturer's maximum rated
motor speed. The motor speed high limit must
exceed the setting in par. 4-11
M,N
Low Limit [RPM] . Only par. 4-11 or 4-12 will
be displayed, depending on other parameters
set in the main menu, and depending on de-
fault settings that are in turn dependant on
global geographical location.
NOTE
The output frequency value of
s
the adjustable frequency drive
must not exceed a value higher
than 1/10 of the switching fre-
quency.
4-14 Motor Speed High Limit [Hz]
Value:
0 - 1,000 Hz
Function:
Enter the maximum limit for motor speed. The
motor speed high limit can be set to corre-
spond to the manufacturer's recommended
maximum frequency of the motor shaft. The
motor speed high limit must exceed the set-
Motor Speed Low Limit [Hz]
ting in par. 4-12
Only par. 4-11 or 4-12 will be displayed de-
pending on other parameters set in the Main
Menu, and depending on default settings spe-
cific to global geographical locations.
NOTE
Max. output frequency cannot
exceed 10% of the inverter
switching
14-01).
drive
Motor Speed
Size related
.
frequency (par.
67
6