Varec 4000 - Manual (Page 19)

9
4000 Installation
2.4.6 ATT Mark/Space Wiring
For an ATT using the Mark/Space field communications option, the following additional wiring connections must be
made. (Refer to Input Power Wiring in Section 6 to determine the minimum wire size required.). See Figure 2-6.
•
Run two twisted pairs of 18 AWG wire (Mark/Space wires) into the ATT through the conduit entry along with the
48 VDC power wiring.
•
Connect the Mark line to terminal 11, M/485-, and the Space line to terminal 12,
S/485+, on the terminal block assembly.
Figure 2-6: Typical Mark/Space Field Wiring
Details of RTU8130 with 8210 expansion
module and ATT termination board wiring
Varec
Model 4000
ATT
External
Power Supply
To Other
4-Wire
Transmitters
in Area 0
Ground shield at RTU8130 ONLY!
Do NOT ground shield at transmitter.
4 Conductor
Cable
18 AWG
Shielded
8203 With 8210
expansion module
Field Junction Box