Planning the electrical installation 39
Selecting the control cables
All control cables must be shielded.
Use a double-shielded twisted pair cable for analog signals. Employ one individually
shielded pair for each signal. Do not use common return for different analog signals.
A double-shielded cable (figure a below) is the best alternative for low-voltage digital
signals but single-shielded (b) twisted pair cable is also usable.
Signals in separate cables
Run analog and digital signals in separate, shielded cables.
Never mix 24 V DC and 115/230 V AC signals in the same cable.
Signals allowed to be run in the same cable
Relay-controlled signals, providing their voltage does not exceed 48 V, can be run in the
same cables as digital input signals. It is recommended that the relay-controlled signals be
run as twisted pairs.
Relay cable type
The cable type with braided metallic screen (eg, ÖLFLEX by LAPPKABEL, Germany) has
been tested and approved by ABB.
To Next Page
Loading...
