19
Duty Cycle
The unit-powered convenience outlet has a duty cycle limita-
tion. The transformer is intended to provide power on an inter-
mittent basis for service tools, lamps, etc; it is not intended to
provide 15-amps loading for continuous duty loads (such as
electric heaters for overnight use). Observe a 50% limit on cir-
cuit loading above 8-amps (i.e., limit loads exceeding 8-amps
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 in-
ternal 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 Bussman
1
“Fusetron” T-15, non-renew-
able screw-in (Edison base) type plug fuse.
Using Unit-mounted Convenience Outlets
Units with unit-mounted convenience outlet circuits will often
require that two disconnects be opened to de-energize all pow-
er 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
50KC 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.
Controller
The controller (see Fig. 23) 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).
Fig. 23 — Controller Assembly
Sensor
The sensor (see Fig. 24) 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 plas-
tic cover permits visual inspections without having to disas-
semble the sensor. The cover attaches to the sensor housing us-
ing four 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
four LEDs (for Power, Trouble, Alarm and Dirty) and a manual
test/reset button (on the left-side of the housing).
1. Bussman and Fusetron are trademarks of Cooper Technologies
Company.
DUCT SMOKE SENSOR
CONTROLLER
CONDUIT NUTS
(SUPPLIED BY INSTALLER)
CONDUIT SUPPORT PLATE
TERMINAL BLOCK COVER
COVER GASKET
(ORDERING OPTION)
CONTROLLER
COVER
FASTENER (2X)
CONDUIT COUPLINGS
(SUPPLIED BY INSTALLER)
CONTROLLER HOUSING
AND ELECTRONICS
ALARM
TROUBLE
POWER
TEST/RESET
SWITCH
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