Parallel Connection Of Firing Pulses; External Amplification Of Firing Pulses - Siemens SINAMICS DCM Operating Instructions Manual

Connecting
6.7 Connecting the firing pulse transformers
6.7.3

Parallel connection of firing pulses

Up to three firing pulse transformers (containing 33 Ω series resistors) can be connected in
parallel. This involves connecting additional "Firing pulse transformer modules" (firing pulse
transformers) (spare part article number 6RY1703-0CM01) via ribbon cables or using two
twisted cables to wire each individual firing pulse transformer in parallel with the terminal with
the same name.
● Two or three firing pulse transformers can be connected in parallel to increase the firing
current of the thyristors. This involves connecting the secondary sides of the firing pulse
transformers in parallel for each firing pulse. The firing current actually achieved should
be checked with a current probe and an oscilloscope.
● For operation with just one current direction (torque direction), the second half of the
"Firing pulse transformer module" can be used for connecting a power unit in parallel or
increasing the firing current. This involves connecting connector X21PAR on the "Firing
pulse transformer module" with connector X22PAR via a 26-pin ribbon cable. Where this
is the case, numbers X21 to X26 on the firing pulse transformers are no longer really
applicable.
NOTICE
Only connect a maximum of three firing pulse transformers to any one firing pulse output!
There is a risk of the firing drivers on the "Power interface for the Control Module" module
being damaged due to overload.
The power interface for the Control Module is protected by F400 fuses (1 A, time-lag).
6.7.4

External amplification of firing pulses

No more than three power units can be connected in parallel unless external firing pulse
amplifiers with their own 24 V supply are connected. The maximum possible load of the
internal firing pulse drivers (open drain) is 2.5 A per pulse.
The associated cables for the electronic ground are also brought out at connectors X21A
and X22A.
The P24 cables of connectors X21A and X22A must not be subjected to loads greater than
1 A (this is not normally connected either). The external firing pulse amplifiers must be
provided with 24 V (22 V to 30 V) via their own power supply. The supply lines for the
external firing pulse amplifiers must be sufficiently interference-proof to prevent thyristors
misfiring under the prevailing conditions.
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SINAMICS DCM Control Module
Operating Instructions, 12/2018, A5E34888669A