
17/89 Device handbook A
PLUS
with / without LED display
,
157
679-19, 04/2016
5.4 Inputs
All voltage measurement inputs must originate at circuit breakers or fuses rated 10 Amps or
less. This does not apply to the neutral connector. You have to provide a method for
manually removing power from the device, such as a clearly labeled circuit breaker or a
fused disconnect switch.
When using
voltage transformers
you have to ensure that their secondary connections
never will be short-circuited.
No fuse may be connected upstream of the
current measurement inputs
!
When using
current transformers
their secondary connectors must be short-circuited
during installation and before removing the device. Never open the secondary circuit under
load.
The connection of the inputs depends on the configured system (connection type). The required device
external fusing of the voltage inputs is not shown in the following connection diagrams.
Single-phase AC mains
1L
Direct connection
L1
L2
L3
N
I1
I2
I3
l
l
l
l
k
k
k
A
PLUS
L1
N
With current and voltage transformer
L1
L2
L3
N
I1
I2
I3
l
l
l
l
k
k
k
A
PLUS
L1
N
K
k
L
l
U
u
V
v
With current transformer
L1
L2
L3
N
I1
I2
I3
l
l
l
l
k
k
k
A
PLUS
L1
N
K
k
L
l