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

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 A7043 modules (firing pulse transformers)
(spare part order 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
● For operation with just one current direction (torque direction), the second half of module
6.7.4

External amplification of firing pulses

No more than 3 power units can be connected in parallel unless external firing pulse
amplifiers with their own 24 V supply are connected. The maximum possible load for 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.
Notes
● External firing pulse amplifiers usually have integrated pull-up resistors at their inputs. If
● Where several firing pulse amplifiers with their own power supply are connected in
SINAMICS DCM Control Module
Operating Instructions, 06.2010, C98130-A7067-A1-02-7619
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.
A7043 can be used for connecting a power unit in parallel or increasing the firing current.
This involves connecting connector X21PAR on module A7043 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.
CAUTION
Never connect more than three firing pulse transformers to any one firing pulse output!
There is a risk of the firing drivers on module A7109 (power interface) being damaged
due to overload.
The power interface (C98043-A7109) is protected by F400 fuses (1 A, time-lag).
this is not the case or interference immunity needs to be increased, additional pull up
resistors can be connected. However, the power pulse current must not exceed 1 A for
each output.
parallel on the input side (e.g. SITOR sets), the inputs will need to be decoupled by
isolation diodes. This is already the case with SITOR sets.
6.7 Connecting the firing pulse transformers
Connecting
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