HEIDENHAIN iTNC 530 HSCI - CML 110 Capacitor Module

416 HEIDENHAIN Technical Manual iTNC 530 HSCI
3.42 CML 110 capacitor module
The CML 110 (Capacitor Module Low Voltage) can be used to realize the
LIFTOFF function if line power fails.
The LIFTOFF function can protect workpieces and tools from damage. When
a power failure occurs and the LIFT OFF function is active, the iTNC 530 HSCI
tries to lift the tool off of the contour, using the residual energy of the DC-link.
In this case, the various releases for operating the control system must be
maintained during the LIFTOFF. The CML 110 ensures the 24 V supply for
this.
Connection The CML 110 capacitor module is connected via X1 parallel to the 24 V power
supply (++/- -).
The two ++ and - - terminals of the CML 110 are each connected to each other
internally. This makes it possible to connect several CMLs 110 in parallel
without needing to use additional external terminals.
Utilizability Calculating the utilizability of the CML 110:
A successful LIFTOFF mainly depends on sufficient energy being available in
the DC-link of the inverter system. Generally it suffices if the energy in the DC-
link is available for the duration of one second. The 24 V supply must also be
ensured for precisely this time. The following formula can be used to check
this:
where:
t = time until U
C
is reached
R
L
= ohmic load of the consumers
C = capacitance of the CML (for CML 110 = 8.3 F)
ln = natural logarithm
U
O
= output load of the power supply unit with which the CML is operated
U
C
= lowest voltage at which the consumers still fulfill their function
Danger
Before service or maintenance work, you must ensure that the CML 110
has been completely discharged.
t = R
L
x C x In (U
O
/U
C
)