4.3.1
External current transformers
When selecting the current transformer, remember that the secondary nominal current must be 5 A. The primary nominal
current is determined by the current consumption of the load. Appropriate PACT current transformers can be found in the
Phoenix Contact INTERFACE catalog.
DANGER: Risk of electric shock
Current transformers and the devices to be connected to them must only be installed when the system power
is switched off.
Observe the order in which the current transformers are connected when wiring them (direction of current
flow). Primary circuit: K-P1 → L-P2; secondary circuit: k-S1 → I-S2
When the current transformer is operated with an open secondary circuit, hazardous voltages may occur at
the secondary terminal blocks.
Do not ground the secondary side of a current transformer in an IT network.
4.3.2
Network types
The device is designed for connection to various network types in two, three or four-wire networks with even or uneven
load.
Network
Short description
type
4NBL
Three-phase network with uneven load, 4-wire with 3 or 4 current transformers
3NBL
Three-phase network with uneven load, 3-wire with 2 or 3 current transformers
4BL
Three-phase network with even load, 4-wire with 1 current transformer
3BL
Three-phase network with even load, 3-wire with 1 current transformer
2BL
Two-phase network, 2-wire with 1 current transformer
1BL
Single-phase network, 2-wire with 1 current transformer
The input circuit of the device must correspond to one of the network types listed.
When measuring by means of transformers, the accuracy is greatly influenced by the quality of the transform-
ers used.
104512_en_02
English
PHOENIX CONTACT
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