MR-2900 Installation Manual
15
Addressable Style 6 (Class A) Circuit
This is a 4-wire power-limited and supervised Style 6 (Class
A) communications circuit using addressable devices. It
requires the use of the MR-2929 or MR-2919 module.
Maximum wire loop lengths are up to 10 000 ft (see Table
3). The recommended wiring is twisted unshielded pair.
Wire capacitance and resistance affects the allowable wire
length. Consult Secutron's Applications Department for
specific requirements. Devices are connected as illustrated
in Figure 14. Use only approved devices. Return wiring
must be in a separate conduit. When using isolators, it is
necessary to put an isolator between panel terminal blocks
and the device.
Table 3: Maximum Wiring Length for Addressable Circuits
Note:
T-taps may NOT be allowed by the authority having jurisdiction. Refer to NFPA 72 and
ULC-S524. This circuit may be wired on any input circuit from 9 to 24 on the MR-2900 terminal
boards.
Notes:
• All distances refer to total wire length.
• This circuit may be wired on any input circuit from 9 to 24 on the MR-2900 terminal boards.
Gauge
Belden No.
Distance
12
9582
3 048m (10 000 ft)
14
9580
2 438m (8 000 ft)
16
9572
1 402m (4 600 ft)
18
9571
975m (3 200 ft)
Figure 14: Addressable Style 6 (Class A)
Wiring
