Shock-Hazard Protection; Leakage Current; Residual Current Protective Device (Rcd); Isolating Transformers - Kollmorgen AKD2G-S Series Installation Manual

3.2 Shock-hazard Protection

3.2.1 Leakage current

Leakage current via the PE conductor results from the combination of equipment and cable
leakage currents. The leakage current frequency pattern includes a number of frequencies,
whereby the residual-current circuit breakers definitively evaluate the 50 Hz current. For this
reason, the leakage current cannot be measured using a conventional multimeter. Contact
our application department for help to calculate the leakage current in your application.
Since the leakage current to PE is more than 3.5 mA, in compliance with IEC61800-5-1 the
PE connection must either be doubled or a connecting cable with a cross-section >10 mm²
must be used. Use the PE terminal and the PE connection screws in order to fulfill this
requirement.
The following measures can be used to minimize leakage currents:
Reduce the length of the engine cable.
Use low capacitance motor cables (➜ # 52).

3.2.2 Residual current protective device (RCD)

In conformity with IEC 60364-4-41 – Regulations for installation and IEC 60204 – Electrical
equipment of machinery, residual current protective devices (RCDs) can be used provided
the requisite regulations are complied with. The AKD2G is a 3-phase system with a B6
bridge. Therefore, RCDs which are sensitive to all currents must be used in order to detect
any DC fault current.
Rated residual currents in the RCDs:
10 to 30 mA
50 to 300 mA
Recommendation: In order to protect against direct contact (with motor cables shorter than
5 m) Kollmorgen recommends that each drive be protected individually using a 30 mA RCD
which is sensitive to all currents.
If you use a selective RCD, the more intelligent evaluation process will prevent spurious trip-
ping of the RCD.

3.2.3 Isolating transformers

When protection against indirect contact is absolutely essential despite a higher leakage cur-
rent, or when an alternative form of shock-hazard protection is sought, the AKD2G can also
be operated via an isolating transformer. A ground-leakage monitor can be used to monitor for
short circuits.
Keep the length of wiring between the transformer and the drive as short as possible.
AKD2G-S Installation, Safety 1 | 3 Product Safety
Protection against "indirect contact" (personal fire protection) for stationary
and mobile equipment, as well as for "direct contact".
Protection against "indirect contact" (personal fire protection) for stationary
equipment
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