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A differential switch upstream will also be triggered for a fault occurring
downstream of the UPS. In calculating reactivity of this switch, account
must be taken of the leakage current of the UPS (approx. 8 mA) plus that
of the load which come together on the UPS's earth conductor.
UPS input
Differential switch
Single-phase
Type B or Type A
Three-phase
Type B
The neutral arrangements are altered only if there is an isolating
transformer or when the UPS operates with a neutral that is disconnected
upstream.
In any case avoid connecting the output neutral with the input neutral
or to the earth as this could damage the UPS.
Reminder : The UPS needs a neutral connection to work properly.
Operation without Neutral may damage the unit.
For installation with change in system earthing arrangement or
galvanic isolation see below schematic
Fig.3-1 Change in SEA or Galvanic isolation
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