Carrier 09FC020, Инструкции по установке, запуску и обслуживанию

Страница: 28 / 72

28
ENABLE-OFF on the unit label diagram and by the switch)
allows the control circuit to be manually disconnected when
necessary.
ENABLE SIGNAL
Remote control of the unit enable function is active when SW2 is
in the remote position. The control requires 24 Vac across termi -
nals TB1-1 and TB1-2. This is the “Enable” signal for the con -
trols. Voltage at these terminals will allow the 09FC unit to operate
when conditions allow.
If connected with a 30XV chiller, this power can be taken from
TB4-1 and TB11-X2. This will “Enable” the 09FC unit whenever
the chiller is “Enabled” locally from SW2.
The 09FC may be kept independent from the chiller by placing
SW2 in the local position. With the switch in this position, the unit
is always enabled.
COMMUNICATION OPTIONS
The 09FC controls can support communication via BACnet
ARC156 (156 kbps) or BACnet MS/TP (9600 bps - 76.8 kbps).
Wiring for BACnet communication is at Net +, Net -, and Shield
at the top left of the 09FC controller. Disconnect the 09FC con -
trols power by placing SW2 in the OFF position before wiring
BACnet cable. While disconnected, check cable for shorts and
grounds. Wire the controllers on an MS/TP network segment in a
daisy-chain configuration. Install a BT485 on the first and last
controller on a network segment to add bias and prevent signal
distortions due to echoing. See Fig. 30 and Table 6 and 7.
NOTE: BT485 does not come with controller. It must be pur -
chased separately.
Fig. 30 — Wiring Diagram
IMPORTANT: For 208-volt systems, sizes 020-040 only,
the primary connection tap for all transformers must be
changed. The factory default setting is for 230-volt. Failure
to connect to the proper tap may result in unreliable
operation.