Honeywell COMMERCIAL PROGRAMMABLE T7350 - Manual (Page 7)

T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT
7 63-4368
Fig. 2. Dimensions of thermostat and subbase in in. (mm).
Communications
The T7350H provides networking capability in a L ON W ORKS®
system using a Free Topology Transceiver (FTT) transformer-
coupled communications port running at 78 kilobits per
second (kbs). The transformer-coupled communications
interface offers a much higher degree of common-mode noise
rejection while ensuring dc isolation. L ON W ORKS® FTT
networks are very flexible and convenient to install and
maintain, but it is imperative that the network layout be
carefully planned and accurate documentation created and
maintained. This aids in compliance verification and future
expansion of the network. It also minimizes unknown or
inaccurate wire run lengths, node-to-node (device-to-device)
distances, node counts, total wire length, inaccurate repeater/
router locations, and misplaced or missing terminations.
L ON W ORKS® networks can be configured in a variety of ways;
refer to the E-Bus FTT Network Wiring Guidelines, form 74-
2865, for a complete description of network topology rules and
maximum network wire length. If longer runs are required, add
a Q7740A 2-way or Q7740B 4-way repeater to extend the
L ON W ORKS® Bus length. Q7751A routers are not supported
on LCBS L ON S PEC ™ configured systems. Approved cable
types for L ON W ORKS® Bus communications wiring are Level
IV, 22 AWG (0.34 sq mm) plenum or non-plenum rated
unshielded, twisted pair, solid or stranded conductor wire.
Refer to Table 2 for a list of Honeywell network cable part
numbers. Other Echelon® approved cable may also be used.
Run communications wiring in a conduit, if needed, with non-
switched 24 Vac or sensor wiring. The Free Topology
Transceiver (FTT) communications L ON W ORKS® Bus supports
a polarity insensitive, free topology wiring scheme that, in turn,
supports star, loop, and/or bus wiring.
6-3/4 (171)
2-3/16 (56)
1-9/16
(40)
4-1/2
(114)
2-1/32
(52)
2-1/32
(52)
4-1/16
(104)
1-5/8
(42)
2-3/8 (60)
3-1/4 (83)
6-9/16 (166) M22432
1-5/8
(42)
SUBBASE