O
UTPUT LINE FUSES
/
THERMAL MAGNETIC SWITCHES
Output protections (recommended values for selectivity)
Normal fuses (gL-gG)
In (Nominal current)/7
Thermal magnetic switches (C Curve)
In (Nominal current)/7
D
IFFERENTIAL
In the absence of an input separation transformer, the neutral coming from the power mains is connected to the output neutral
of the UPS. The system neutral connectivity is not modified:
THE INPUT NEUTRAL IS CONNECTED TO THE OUTPUT NEUTRAL
THE DISTRIBUTINO SYSTEM POWERING THE UPS IS NOT MODIFIED BY THE UPS
ATTENTION: ensure proper connection to the input neutral as failure to do so can damage the
UPS.
Neutral connectivity is modified only if an isolation transformer is present or when the UPS operates with neutral
disconnected upstream.
When operating with mains power present, a differential switch inserted in the input can intervene since the output circuit is not
isolated from the input circuit. In any case, it is always possible to insert more differential switches in the output, possibly
coordinated with those present in the input.
The differential switch set upstream must have the following characteristics:
suitable differential current for the sum of UPS + load; it is advisable to keep an adequate margin to prevent
inopportune interventions (300mA recommended)*
type B or type A
delay higher than or equal to 0.1s
* The load dispersion current is added to that of the UPS on the ground protection conductor
www.upsdirect.com