Installation manual

UNIPOWER
Installation manual PQ Secure
29
4.6.3 Isolated (ungrounded) 3-wire systems
Typical examples: Industrial MV networks.
In a 3-phase, 3-wire network without neutral conductor it is also common to isolate the network and
leave it ungrounded.
Connect you’re UP-2210 to measure line-line voltages U1-U3 and phase currents I1-I3 according to
one of the sections 4.4.3, 4.4.4, 4.4.5 and 4.4.6 depending on how many PT/CT there is.
Channels U4 and I4 is normally not used. Connect them to ground.
4.6.4 Low voltage 4- or 5-wire systems
In a 4-wire network with neutral conductor or 5-wire network with neutral and ground connectors
phase (line-neutral) voltages should be measured.
Connect you’re UP-2210 to measure line-neutral voltages U1-U3 and phase currents I1-I3
according to section 4.4.2.
Connect channel I4 to measure the neutral current.
Channel U4 could be used to measure the voltage between neutral and ground. If it is not used,
connect it to ground.
4.6.5 Alternative connection option for MV/HV 3-wire systems
From a Power Quality point of view line-line voltages should always be measured (see sections
4.6.1, 4.6.2 and 4.6.3). This is in accordance with existing Power Quality standards like EN 50160.
As an alternative, from a disturbance point of view, you could choose to measure line-ground
voltages instead. With this configuration you can see earth faults per phase. This configuration is
mainly a tool for analyzing disturbances.
Connect you’re UP-2210 to measure line-neutral voltages U1-U3 and phase currents I1-I3
according to section 4.4.8.
If the system is impedance grounded, connect channel U4 to measure the transformer neutral point
voltage U
n
.
Channel I4 is normally not used. Connect it to ground.
4.7 Digital in- and outputs
The UP-2210 can be equipped with 8-32 digital inputs and 2-4 digital outputs. They can be used to
record external events to the PQ Secure system, or send signals to other equipment in case of a sag/
swell or transient. These in-/ outputs are used in a similar way if the recorder is used as a fault
recorder.
The configuration of the digital in-/outputs is made via the PQ Online program. For more
information about this, please see the “PQ Secure User manual”. These functions are optional
modules.
4.7.1 Connection of digital inputs
By connecting a signal voltage (max. 250 V DC) to the UP-2210’s digital inputs from external
equipment (e.g. circuit breaker, harmonics filter), events can be registered and recordings can be
trigged as a result of change in the digital signal.