Calculation Of The Exact Filter Size Needed - Danfoss VLT AHF 005 Operating Instructions Manual

Ordering numbers, 690 V 50 Hz
I Typical Motor Used
AHF,N
[kW]
43 A
72 A
101 A
144 A 110, 132
180 A
217 A
289 A
324 A
370 A
• Please note that the matching of the typical Danfoss frequency converter and filter is pre-calculated based on
500V and assuming typical motor load. VLT 5000 series is based on a 160 % torque application, while the VLT
8000 series are based on 110% torque application.
The pre-calculated filter current may be varying from the input current ratings of VLT 5000 and VLT 8000 series
as stated in the respective operating instructions, as these numbers are based on different operating conditions.

Calculation of the exact filter size needed

For optimal performance the harmonic filter should be
sized for the line input current to the frequency con-
verter, i.e. the input current drawn based on the ex-
pected load of the frequency converter and not the size
of the frequency converter itself!
The line input current to the frequency converter
(I ) can by calculated using the nominal motor cur-
FC,L
) and displacement power factor (Cos φ)) of
rent (I
M,N
the motor. Both data are normally printed on the name-
plate of the motor. In the case where the nominal motor
voltage (U ) is unequal to the actual line-line voltage
M,N
(U ) the calculated current must be corrected with the
L
ratio between these voltages as shown in the equation
below.
6
Danfoss ordering number
AHF 005
37, 45 130B2328
55, 75 130B2330
90 130B2331
130B2333
160 130B2334
200 130B2335
250 130B2331 &
130B2333
315 130B2333 &
130B2334
400 130B2334 &
130B2335
AHF 005/010
Typical Danfoss frequency converter
AHF 010 VLT 5000 160 %
130B2293 5042, 5052
130B2295 5062, 5072
130B2296
130B2298 5122, 5152
130B2299
130B2300
130B2301
130B2302
130B2304
The harmonic filter chosen must have a nominal cur-
rent (I ) equal to or larger than the calculated
AHF,N
frequency converter line input current (I
If several frequency converters are to be connected to
the same filter, the harmonic filter must be sized ac-
cording to the sum of the calculated line currents.
If the harmonic filter is sized for the load,
and the motor of the corresponding fre-
quency converter is changed, the current
must be re-calculated to avoid overload of
the harmonic filter.
®
MG.80.B5.02 - VLT is a registered Danfoss trademark
series •
VLT 8000 HVAC
8052
8062, 8072
5102 8102
8122, 8152
5202 8202
5252 8252
5302 8302
5352 8352
8402
).
FC,L