
Technical Specifications
Overvoltage
involved the internal brake resistor might reach its thermal limit. It will turn off and the DC-bus voltage
might increase further until the drives turn off. Then the axis does not stop and might cause mechanical
damage.
This failure is avoided by using an external brake resistor or reducing the deceleration of the drives.
Slower stopping reduces the load on the brake resistor.
3.8.2 External Brake Resistor
The optional external brake resistor must be dimensioned properly to account for the amount of energy
to be dissipated in the axis system.
It is recommended to use a resistor that is protected against over-temperature. Contact manufacturer
for dimensioning.
3.8.3 Overvoltage Protection
If the external braking resistor is not dimensioned correctly, the DC-Bus voltage may exceed the maxi-
mum DC voltage level. The TP indicates this by switching the Status output to 0V. If the voltage further
increases and reaches the internal limit of the drives, they will protect themselves by turning off their
semiconductor switches. The axis is not decelerated anymore and the voltage will not increase any fur-
ther. However, turning off the drives during fast motion leaves the axis at the original speed. The axis
might crash into its end-limits, which might cause significant damage to the mechanical system.
Therefore it is important to choose a well dimensioned braking resistor. Also, the Status output signal
and the overvoltage error message of the drives may be used by the control system for damage preven-
tion.
3.9 LED Diagnostics and Status
There is a green and a red LED for diagnostics. The green LED indicates the DC-Bus voltage. Steady on
means the voltage is in its normal range. Flashing short means the voltage is too low and flashing long
means the voltage is too high. The red LED indicates any caution or error.
Green LED
Red LED
Status Output
No line power
off
off
0V
Charging DC-Bus
flashing short
off
0V
Ready
on
off
24V
One AC-Line missing
(3-Phase Mode only)
[according to device state]
flashing short
0V
Line disturbance check (20ms)
on
on
24V
Line disturbance (1s)
on
on
0V
HWTP50-TP350_E_HardwareManual_EP008
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