Electrical Installation; Over Temperature Protection; Capacitor Disconnect - Danfoss AHF005 Design Manual

How to Install

6.2 Electrical Installation

6.2.1 Over Temperature Protection

The Danfoss harmonic filters AHF005 and AHF010 are all
equipped with a galvanic isolated switch (PELV) that is closed
under normal operating conditions and open if the filter is
overheated.
NOTE
The over temperature protection must be used to
prevent damage of the filter caused by over tempera-
ture. An immediate stop or a controlled ramp down
within max. 30 s has to be performed to prevent filter
damage.
There are many ways the switch can be used and one example
is to connect terminal A of the harmonic filter to terminal 12 or
13 (voltage supply digital input, 24 V) of the Danfoss frequen-
cy converter and terminal B to terminal 27. Program digital
input terminal 27 to Coast Inverse. The frequency converter
will coast the motor and thereby unload the filter if an over
temperature is detected. Alternatively use terminal 12/33 and
set par. 1-90 to motor terminal protection.
AHF005/010 Design Guide
NOTE
The maximum rating of the over temperature contactor
is 250 V AC and 10 A.

6.2.2 Capacitor Disconnect

The power factor of the harmonic filter AHF 005/010 is
decreasing with decreasing load. At no load the power factor
is zero and the capacitors produce leading current of approx-
imately 25 % of rated the filter current. In applications where
this reactive current is not acceptable the terminals X3.1, X3.2,
X3.3 and X4.1, X4, X4.3 provide access to the capacitor bank,
so it can be disconnected.
Default (on delivery) 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 that no
capacitor disconnect is required, no changes should be made
to these shorted terminals.
If a disconnection of the capacitors is required a three-phase
contactor should be placed between terminals X3 and X4. It is
recommended to use AC3 contactors.
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MG.80.C3.02 - VLT is a registered Danfoss trademark
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