D7024
| Operation and Installation Guide | 4.0 Control Panel Terminal Connections
20
Bosch | 7/05 | 31499J
Avoid shielded or twisted pair wire, except for special applications where a reduced length of wiring (approximately
50%) is acceptable for an unusually harsh electrical environment to be tolerated.
The length of wire allowed between the control panel and the last device on a wiring run depends on the current
drawn on that wiring run. Reducing the number of devices on a wiring run allows the individual runs to be longer.
When devices are all the same type on a given wire run, use the guidelines in
Table 9
.
When there are more than one type of device installed on a given wiring run, total the alarm current drawn by all
the devices on the wiring run to determine the maximum allowable distance between the option bus terminals on
the control panel and the last device on the wire run (the device furthest from the control panel).
Add all alarm loads for option bus devices on the wire run, and use to determine the maximum allowed length for
the run. For example, if the total load of option bus devices on a particular run is 400 mA, the maximum length of
the run can be up to 500 ft (152.4 m). No more than 4000 ft (1219.2 m) of wire can be connected to the option bus
terminals, even if the individual lengths of the runs are all within limits.
Figure 12
shows the lengths for 18 AWG (1.2 mm). For 16 AWG (1.5 mm) wire, cable lengths can be 1.5 times longer,
and for 14 AWG (1.8 mm) wire, cable lengths can be 2.5 times longer. The maximum length of connected wire
(4000 ft [1219 m]) still applies.
Table 9:
Option Bus Wiring Guidelines
Device
Number of
Wiring Run
Maximum Allowed Cable Length to
Last Device (18 AWG [1.2 mm])
Current Draw (for reference)
D7030 LED Annunciator
1
1000 ft (304 m)
175 mA
D7030 LED Annunciator
2
500 ft (152 m)
175 mA x 2 = 350 mA
D7030 LED Annunciator
4
250 ft (76 m)
175 mA x 4 = 700 mA
D7033 Remote Keypad
1
2000 ft (608 m)
100 mA
D7033 Remote Keypad
2
21000 ft (304 m)
100 mA x 2 = 200 mA
D7033 Remote Keypad
4
500 ft (152 m)
100 mA x 4 = 400 mA
D7035 Remote Relay
1
500 ft (152 m)
330 mA
D7035 Remote Relay
2
250 ft (76 m)
330 mA x 2 = 660 mA
D7036 LCD Annunciator
1
2000 ft (608 m)
100 mA
D7036 LCD Annunciator
2
1000 ft (304 m)
100 mA x 2 = 200 mA
D7036 LCD Annunciator
4
500 ft (152 m)
100 mA x 4 = 400 mA
D7038 Remote NAC
2
4000 ft (1216 m)
< 50 mA each
Figure 12:
Option Bus Cable Length versus Current Draw
1 – Cable length (ft)
2 – Current draw (mA)
1
2
0
200
400
600
800
1000
0
2000
1500
500
1000
2500
