Controls, Start-Up, Operation, Service and ... - Climayoreo

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Alarms
CARRIER COMFORT NETWORK ® INTERFACE —
The 48/50P Series units can be connected to the CCN if
desired. See Fig. 36. The communication bus wiring is a
shielded, 3-conductor cable with drain wire and is field supplied
and installed. See the Installation Instructions for wiring
information.
The system elements are connected to the communication
bus in a daisy chain arrangement. The positive pin of each
system element communication connector must be wired to the
positive pins of the system elements on either side of it. This is
also required for the negative and signal ground pins of each
system element. Wiring connections for CCN should be made
at the COMM board. See Fig. 20. Consult the CCN Contractor’s
Manual for further information.
NOTE: Conductors and drain wire must be 20-AWG
(American Wire Gage) minimum stranded, tinned copper.
Individual conductors must be insulated with PVC, PVC/
nylon, vinyl, Teflon, or polyethylene. An aluminum/polyester
100% foil shield and an outer jacket of PVC, PVC/nylon,
chrome vinyl, or Teflon with a minimum operating temperature
range of –20 C to 60 C is required.
It is important when connecting to a CCN communication
bus that a color-coding scheme be used for the entire network
to simplify the installation. It is recommended that red be used
for the signal positive, black for the signal negative and white
for the signal ground. Use a similar scheme for cables containing
different colored wires.
At each system element, the shields of its communication
bus cables must be tied together. If the communication bus is
entirely within one building, the resulting continuous shield
must be connected to a ground at one point only. If the communication
bus cable exits from one building and enters another,
the shields must be connected to grounds at the lightning
suppressor in each building where the cable enters or exits the
building (one point per building only). To connect the unit to
the network:
1. Turn off power to the control box.
2. Cut the CCN wire and strip the ends of the red (+), white
(ground), and black (–) conductors. (Substitute appropriate
colors for different colored cables.)
3. Connect the red wire to (+) terminal on the COMM
board, the white wire to COM terminal on the COMM
board, and the black wire to the (–) terminal on the
COMM board.
4. The RJ14 CCN connector on the COMM board can also
be used, but is only intended for temporary connection
(for example, a laptop computer running Service Tool).
ENTER
Co m f o r t Link
E S C
N A V I G A T O R
1 2 . 5 8
5 4 . 6 F
4 4 .1 F
4 4 . 0 F
M O D E Alarm Status
Fig. 35 — Accessory Navigator Display
137
5. Restore power to unit.
IMPORTANT: A shorted CCN bus cable will prevent
some routines from running and may prevent the unit
from starting. If abnormal conditions occur, unplug the
connector. If conditions return to normal, check the
CCN connector and cable. Run new cable if necessary.
A short in one section of the bus can cause problems
with all system elements on the bus.
SERVICE
Service Access — All unit components can be reached
through clearly labeled hinged access doors. These doors are
not equipped with tiebacks, so if heavy duty servicing is needed,
either remove them or prop them open to prevent accidental
closure.
Each door is held closed with 3 latches. The latches are
secured to the unit with a single 1/ 4-in. –20 x 1/ 2-in. long bolt.
See Fig. 37.
To open, loosen the latch bolt using a 7 / 16-in. wrench. Pivot
the latch so it is not in contact with the door. Open the door. To
shut, reverse the above procedure.
NOTE: Disassembly of the top cover may be required under
special service circumstances. It is very important that the orientation
and position of the top cover be marked on the unit
prior to disassembly. This will allow proper replacement of the
top cover onto the unit and prevent rainwater from leaking into
the unit.
IMPORTANT: After servicing is completed, make sure
door is closed and relatched properly, and that the
latches are tight. Failure to do this can result in water
leakage into the indoor-air section of the unit.
COMPRESSORS
Sizes 030,035 — Access to the compressors is below the unitcontrol
box.
Sizes 040-060 — Access to the compressors is through the
doors on the condenser end of the unit. This door also provides
access to the discharge service valves, filter driers, the crankcase
heaters, and the high-pressure and low-pressure switches.
Circuit A is always the compressor on the left when facing
main control box.
Sizes 070-100 — Each compressor is readily accessible from
sides of unit.
LIQUID SERVICE VALVES, SUCTION SERVICE
VALVES, AND SIGHT GLASSES
Sizes 030-060 — Access to these components is through the
access panel on the right side of the unit. See Fig. 38. There is
also a Schrader port in each suction line that is accessible
through this same panel.
Sizes 070-100 — Access to these components is from the side
of the unit.
SUPPLY-FAN MOTORS, PULLEYS, AND BELTS — Access
to these components is through the 2 doors labeled FAN
SECTION on each side of the unit.
POWER EXHAUST MOTORS, PULLEYS, AND BELTS —
Access to these components is through the door below the side
economizer hoods on both sides of the unit. See Fig. 39.
RETURN AIR FILTERS — Access to these filters is through
the door marked FILTER SECTION.
UNIT CONTROL BOX — Access to this component is
through the doors marked ELECTRICAL SECTION on the
condenser end of the unit.
GAS HEAT SECTION (48P Only) — Access to the gas heat
section is through the door labeled HEAT SECTION on the