Completing Heater Installation; Smoke Detectors; System; Controller - Bryant Preferred 549K 04-06 Service And Maintenance Instructions

Line-break/auto-reset limit switches, 24-v control side
break/auto-reset and line-break/non-resettable "one shot" limit
switches are mounted on the base plate of each heater module.
See Fig. 36. These are accessed through the indoor access
panel. Remove the switch by removing two screws into the
base plate and extracting the existing switch.
Fan stator/manual reset limit switch is located in the side plate
of the indoor (supply) fan housing. See Fig. 36.
CONTROL SIDE
AUTOMATIC RESET
LIMIT SWITCHES
Fig. 36 — Typical Location of Heater Limit Switches
(3-phase heater shown)

Completing Heater Installation

FIELD POWER CONNECTIONS
Tap conductors must be installed between the base unit's field
power connection lugs and the single point box (with or with-
out fuses). See Fig. 37. Refer to unit wiring schematic. Use
copper wire only. For connection using the single point box
without fuses, connect the field power supply conductors to the
heater power leads and the field-supplied tap conductors inside
the single point box. Use UL-approved pressure connectors
(field-supplied) for these splice joints.
LOW-VOLTAGE CONTROL CONNECTIONS
Pull the low-voltage control leads from the heater module(s) —
ORN, VIO and BRN — to the 4-pole terminal board TB4 located
on the heater bulkhead to the left of heater 1. Connect the ORN
lead to terminal TB4-1. Connect the VIO lead to terminal TB4-2.
Connect the BRN lead to terminal TB4-3. See Fig. 37.

SMOKE DETECTORS

Smoke detectors are available as factory-installed options on
549K models. Smoke detectors may be specified for supply air
only, for return air without or with economizer, or in combina-
tion of supply air and return air. Return air smoke detectors are
arranged for vertical return configurations only. All compo-
nents necessary for operation are factory-provided and mount-
ed. The unit is factory-configured for immediate smoke detec-
tor shutdown operation; additional wiring or modifications to
unit terminal board may be necessary to complete the unit and
smoke detector configuration to meet project requirements.

System

The smoke detector system consists of a four-wire controller and
one or two sensors. Its primary function is to shut down the roof-
top unit in order to prevent smoke from circulating throughout
the building. It is not to be used as a life saving device.
T
STATOR MANUAL
RESET LIMIT
SWITCH
LINE BREAK
"ONE SHOT"
LIMIT SWITCHES

Controller

The controller (see Fig. 38) includes a controller housing, a
printed circuit board, and a clear plastic cover. The controller
can be connected to one or two compatible duct smoke sensors.
The clear plastic cover is secured to the housing with a single
captive screw for easy access to the wiring terminals. The con-
troller has three LEDs (for Power, Trouble and Alarm) and a
manual test/reset button (on the cover face).
21
UCB
2 PNK
3 ORN
TRAN 1
C
ORN
1
TB4
VIO
Field
Connections
Fig. 37 — Accessory Electric Heater Control Connections
DUCT SMOKE SENSOR
CONTROLLER
CONTROLLER HOUSING
AND ELECTRONICS
CONDUIT COUPLINGS
(SUPPLIED BY INSTALLER)
FASTENER (2X)
ALARM
Fig. 38 — Controller Assembly
PNK BRN
2
3
VIO BRN BRN
Elec Htr
VIO HR2 BRN
VIO HR1 BRN
HR1: Heater Circuit 1
HR2: Heater Circuit 2
(if two-circuit module installed)
CONDUIT NUTS
(SUPPLIED BY INSTALLER)
CONDUIT SUPPORT PLATE
TERMINAL BLOCK COVER
COVER GASKET
(ORDERING OPTION)
CONTROLLER
COVER
TROUBLE
POWER
TEST/RESET
SWITCH