GAI-Tronics DEX-101 Hazardous Area Driller's Intercom Station - Manual (Page 9)

Pub. 42004-679L2G
M ODEL DEX-10 X AND DEX-20 X D RILLER ’ S I NTERCOM S TATIONS Page 8 of 13
f:\standard ioms - current release\42004 instr. manuals\42004-679l2g.doc
07/13
Auxiliary Devices
Terminal block TB1 is provided for connection of the speaker, system cable, footswitch, and beacon.
This terminal block accepts a #12–22 AWG wire. Refer to Table 2 for the recommended conductor sizes.
Conductor ends can be stripped and terminated with or without a wire ferrule.
Table 2. Recommended Cable Sizes
Cable Use Size
System Digital: Two-conductor twisted pair, No. 22 AWG is typical
Analog: Four-conductor twisted pair (A/B twist; C/D twist), No. 22 AWG is
typical
Power Three-conductor, No. 12 AWG is typical
Beacon Two-conductor, No. 18 AWG is typical (for digital models only)
Footswitch Two-conductor, No. 22 AWG is typical
Speaker Cable Two-conductor twisted pair, No. 18 AWG is typical
1. Install the system cable on TB1 system terminals A–D. Each system cable must be home run to the
Central. Digital stations require termination of a 2-conductor twisted pair cable on system terminals
A and B only. Analog stations require termination of a 4-conductor twisted pair cable (A/B twist &
C/D twist) on system terminals A–D. Refer to Table 3 for the maximum system cable lengths.
Table 3. Maximum System Cable Lengths
Digital Models Analog Models
Cable Capacitance No. 22 AWG No. 20 AWG No. 22 AWG No. 20 AWG
30.5 nf/1000 feet 6562 feet 6562 feet 4921 feet 6562 feet
13.7 nf/1000 feet 9843 feet 9843 feet
2. Install the speaker cable on TB1 Speaker terminals LS1 and LS2. Refer to Table 2 for recommended
conductor sizes.
3. Install the beacon control cable on TB1 terminals C1 and C2. This control output is available on
digital stations only. Refer to Table 2 for recommended conductor sizes.
4. Install the footswitch cable on TB1 terminals N.O. and C. Refer to Table 2 for recommended
conductor sizes.
After all connections are made, inspect and clean the machined and threaded surfaces of both the
termination cover and box. Clean the surfaces by wiping with a clean, lint-free cloth. Apply a light coat
of Killark LUBG lubricant to the cover threads. Install and hand-tighten the cover to the box.