Power Wiring; Capacitor Disconnect - Danfoss AHF 005 Operating Instructions Manual

4 Installation

4.1.3 Power Wiring

Standard connection
Supply voltage must be connected to the terminals X1.1, X1.2 and X1.3. The frequency converter supply terminals L1, L2 and L3 must be connected to
the filter module terminals X2.1, X2.2 and X2.3.
Paralleling of FC's
If several frequency converters are to be connected to the harmonic filter, the connection is similar to the standard connection - The supply terminals
L1, L2 and L3 of several frequency converters must be connected to the filter module terminals X2.1, X2.2 and X2.3.
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NB!
If several FC's are to be connected to the same filter, the harmonic filter must be sized according to the sum of the calculated input
current to the FC's.
Paralleling of filters
If the mains input current of the frequency converter exceeds the nominal current of the largest harmonic filter, several harmonic filters can be paralleled
to achieve the necessary rating. Supply voltage must be connected to the terminals X1.1, X1.2 and X1.3 of the filters. The frequency converter supply
terminals L1, L2 and L3 must be connected to the filter modules terminals X2.1, X2.2 and X2.3.
NB!
Filters of different current ratings can be paralleled. The rating of the filter becomes the sum of the individual current ratings.

4.1.4 Capacitor Disconnect

The power factor of the harmonic filter AHF 005/010 is decreasing with decreasing load. At zero load the Power Factor becomes zero and the capacitors
produce approximately 30% leading current compared to the rated current of the filter. The reactive current generated by the filter at partial load is
normally not of any concern, mainly because of the small current compared to the system capacity (max 30%) as well as the fact that other load normally
compensates the capacitive current.
In applications where this reactive current may not be accepted, Terminals X3.1, X3.2, X3.3 and X4.1, X4, X4.3 are giving acces to the filter capacitors.
As default (on delievery) the wiring will shorten Terminal X3.1 with X4.1, X3.2 with X4.2 and X3.3 with X.4.3. In the case of that no capacitor disconnect
is required no changes should be made. If capacitor disconnecet is required a three-phase contactor should be placed between terminals X3 and X4.
Size the contactor and wiring according to below table. It is recommended only to use contactors with damping resistors.
NB!
It is not allowed to use one common 3 poled contactor in several paralleled AHF at once to disconnect the capacitors.
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MG.80.C1.02 - VLT is a registered Danfoss trademark
AHF 005/010 Operating Instructions