AFP-400 Installation
PN 50253:A2 03/12/96
4-17
Connecting VCM-4 Telephone Circuits
Follow these guidelines when connecting VCM-4 telephone circuits:
1) Telephone circuits are supervised and power-limited.
2) Use twisted-pair cable for telephone circuit wiring.
3) Maximum telephone circuit wire resistance is 40 ohms.
4) Install End of Line Resistors according to the table below:
Overview
Typical Telephone Circuits
Four-wire Circuit
4.7K ELR
part no. 71245
End each unused VCM-4
circuit with a 4.7K ELR
(part no. 71245)
VCM-4 or VCE-4
Telephone
Circuits
Resistor Requirements
For ELR connection to devices...
Use resistor part number...
with terminals
71252
with flying leads
71245
installed in Canada
N-ELR
Wiring Diagram
Telephone
Stations
VCM-4
(configured
for Telephone
operation)
Four-wire
Telephone Circuit
4.7K, 1/2 watt ELR
Part no. 71252
Optional Telephone Expander Circuits
(provides positions E, F, G, and H)
Telephone Circuits
positions A, B, C, and D
Connections
to FFT-7
