Applicable Standards; Safety; Twelve-Pulse Units; Description Of The +Q954 Option - ABB ACS800 Series Hardware Manual

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Applicable standards

The following standards concern earth fault monitoring in IT systems:
• IEC/EN 60204-1:1997 "Safety of machinery – Electrical equipment of machines –
Part 1: General requirements".
• IEC 60364-4-41:2001 "Electrical installations of buildings – Protection for satefy –
Protection against electrical shock".

Safety

Follow the safety instructions in IRDH275 Operating Manual by Bender (code:
TGH1386).
The insulation monitoring device is constructed according to state-of-the-art and
recognised technical safety rules. Nevertheless, when the device is used, hazards
may occur to the life and limb of the user or of third parties, or there may be adverse
effects on the monitoring device or on other valuable property. The monitoring device
must only be used
• for the purpose for which it is intended
• when it is in perfect technical condition as far as safety is concerned.
The earth fault monitoring function (+Q954) is not a personal safety or fire protection
feature.

Twelve-pulse units

The supply voltage to the insulation monitoring device is taken from the L11-L21-L31
branch in six- and twelve-pulse connected drives. In units with line contactor, the
insulation monitoring device detects earth faults in both supply branches when the
line contactor is closed. When the line contactor is open, only the measured branch
is monitored.

Description of the +Q954 option

Earth faults in IT (ungrounded) systems are monitored by a Bender IRDH275
insulation monitoring device.
Earth fault monitoring in IT (ungrounded) systems (+Q954)