16
UMC710D4_D00379_00_M_XXEN / 01.2020
Installation and connection
Changeover modules with switch disconnectors
For changeover modules with switch disconnectors, the following applies:
I
v
= Manufacturer‘s technical data for short-circuit protection
I
e
= Manufacturer‘s technical data for rated continuous current
3.1.2 Selecting a fuse with several loads at one phase conductor
This circuit branches into several load groups. The result is that every fuse of every load group is
moved downstream of the changeover module. Regardless of this, the maximum possible fuse is
calculated in the same way as described above.
The rating of fuse F1 or F2 must be coordinated with the rating of fuse F3 (and of course F4 and
F5) so that selective shutdown is ensured. The fuse specified by the manufacturer for the IT sys-
tem transformer must therefore be at least two stages smaller in rating than the fuse calculated
using the formula above for the changeover module. Of course, the total nominal current for the
changeover module must be calculated from the sum and simultaneity factor of all load groups
connected, and the required or minimum rated current calculated according to the formula
above.
The values listed in the ordering information apply for the changeover modules.
3.2
Changeover module
i
Connect the changeover module according to the supplied circuit diagram.
3.2.1 UMC710D4-..HA
Version UMC710D4-..HA provides the relay module RK474 for the output of different messages via
relay contacts. This version is suitable for the following application:
• Use in combination with the alarm indicator and operator panel TMX-HA.
• Output of messages about the condition of the changeover module via relay contacts,
F1
F2
F3
F4
F5
Four-pole
Changeover module
Two-pole
circuit breaker
2
2
2
4
4
