Commissioning Instructions

Safety notes
1
A6V11604303_en--_e
Restricted 2022-01-28
9 | 36
CAUTION
Device safety
Device-related safety is guaranteed, among others, by low voltage power supply
AC 24 V, DC 24 V and double insulation between the mains voltage AC 230 V,
AC 24 V circuits and the housing or Power over Ethernet (PoE Class 4).
Comply with specific regulations for electrical wiring per the following sections.
CAUTION
Grounding ⊥ (system neutral AC/DC 24 V)
Observe the following points when grounding ⊥ AC 24 V (system neutral):
● Operating voltage of AC 24 V is permitted in principle for both grounded as
well as non-grounded system neutrals. Local regulations and customs apply
accordingly. Grounding may be required or not allowed for functional reasons.
● Recommendation: AC 24 V systems are generally grounded unless otherwise
not recommended by the manufacturer.
● In order to avoid ground loops, connect systems with PELV to the ground at
one location only (especially for transformers), unless otherwise indicated.
● The same applies to DC 24 V power supplies.
CAUTION
Functional ground
The connections of the functional earth must be connected on the installation side
with the building grounding system (PE).
CAUTION
Operating voltage AC/DC 24 V
It must meet requirements for SELV or PELV. Permissible deviation to nominal
voltage:
At the transformer/power unit: AC / DC 24 V -10 … + 20%
At the end device (web server): AC 24 V ±20%, DC 24 V ± 20%
At the end device (touch panel): AC 24 V ±20%, DC 24 V ± 20%
CAUTION
Transformer specification AC 24 V
IEC: Use safety insulating transformers as per IEC 61558 with double insulation
designed for 100% duty to supply SELV or PELV circuits.
USA: Class 2 circuits per UL 5085-3
Power taken from the transformer should be at least 50% of nominal load for
efficiency reasons (effectiveness).
Transformer nominal power should be at least 25 VA. For smaller transformers,
the ratio of open circuit voltage to full load is unfavorable (> + 20 %).