Duty Cycle; Maintenance; Fuse On Powered Type; Smoke Detectors - Carrier 48GC 04-06 Series Service And Maintenance Instructions

UNIT CONNECT
VOLTAGE AS
208, 230 240
460 480
575 600
Fig. 34 — Powered Convenience Outlet Wiring

Duty Cycle

The unit-powered convenience outlet has a duty cycle limitation.
The transformer is intended to provide power on an intermittent
basis for service tools, lamps, etc; it is not intended to provide 15A
loading for continuous duty loads (such as electric heaters for
overnight use). Observe a 50% limit on circuit loading above 8A
(i.e., limit loads exceeding 8A to 30 minutes of operation every
hour).

Maintenance

Periodically test the GFCI receptacle by pressing the TEST button
on the face of the receptacle. This should cause the internal circuit
of the receptacle to trip and open the receptacle. Check for proper
grounding wires and power line phasing if the GFCI receptacle
does not trip as required. Press the RESET button to clear the
tripped condition.

Fuse on Powered Type

The factory fuse is a Bussmann
renewable screw-in (Edison base) type plug fuse.
USING UNIT-MOUNTED CONVENIENCE OUTLETS
Units with unit-mounted convenience outlet circuits will often re-
quire that 2 disconnects be opened to de-energize all power to the
unit. Treat all units as electrically energized until the convenience
outlet power is also checked and de-energization is confirmed.
Observe National Electrical Code Article 210, Branch Circuits, for
use of convenience outlets.

SMOKE DETECTORS

Smoke detectors are available as factory-installed options on
48GC 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 components
1. Third-party trademarks and logos are property of their respective
owners.
PRIMARY TRANSFORMER
CONNECTIONS TERMINALS
L1: RED +YEL H1 + H3
L2: BLU + GRA H2 + H4
L1: RED H1
Splice BLU + YEL H2 + H3
L2: GRA H4
L1: RED H1
L2: GRA H2
™1 Fusetron ™1 T-15, non-
necessary for operation are factory-provided and mounted. The
unit is factory-configured for immediate smoke detector shut-
down operation; additional wiring or modifications to unit termi-
nal board may be necessary to complete the unit and smoke de-
tector configuration to meet project requirements.

System

The smoke detector system consists of a 4-wire controller and
one or 2 sensors. Its primary function is to shut down the rooftop
unit in order to prevent smoke from circulating throughout the
building. It is not to be used as a life saving device.

Controller

The controller (see Fig. 35) includes a controller housing, a print-
ed circuit board, and a clear plastic cover. The controller can be
connected to one or 2 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 controller has 3 LEDs
(for Power, Trouble and Alarm) and a manual test/reset button (on
the cover face).

Smoke Detector Sensor

The smoke detector sensor (see Fig. 36) includes a plastic housing,
a printed circuit board, a clear plastic cover, a sampling tube inlet
and an exhaust tube. The sampling tube (when used) and exhaust
tube are attached during installation. The sampling tube varies in
length depending on the size of the rooftop unit. The clear plastic
cover permits visual inspections without having to disassemble
the sensor. The cover attaches to the sensor housing using
4 captive screws and forms an airtight chamber around the sensing
electronics. Each sensor includes a harness with an RJ45 terminal
for connecting to the controller. Each sensor has 4 LEDs (for Pow-
er, Trouble, Alarm and Dirty) and a manual test/reset button (on
the left-side of the housing).
Duct Smoke Sensor
Controller
Controller
Housing
and Electronics
Conduit Couplings
(Supplied by Installer)
Fastener (2X)
Alarm
Fig. 35 — Controller Assembly
Air is introduced to the duct smoke detector sensor's sensing
chamber through a sampling tube that extends into the HVAC duct
and is directed back into the ventilation system through a (shorter)
exhaust tube.
The difference in air pressure between the 2 tubes pulls the sam-
pled air through the sensing chamber. When a sufficient amount of
smoke is detected in the sensing chamber, the sensor signals an
alarm state and the controller automatically takes the appropriate
21
Conduit Nuts
(Supplied by Installer)
Conduit Support Plate
Terminal Block Cover
Cover Gasket
(Ordering Option)
Controller
Cover
Trouble
Power
Test/Reset
Switch