Start-Up; Unit Preparation; Unit Setup; Internal Wiring - United Technologies Carrier Weathermaker 48A2 Controls, Start-Up, Operation, Service, And Troubleshooting

Single package large rooftop units with comfortlink version 8.x controls
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GENERICS STATUS DISPLAY TABLE — The GENERICS
points table allows the service/installer the ability to create a
custom table in which up to 20 points from the 5 CCN
categories (Status, Config, Service-Config, Setpoint, and
Maintenance) may be collected and displayed.
In the Service-Config table section, there is a table named
"generics." This table contains placeholders for up to 20 CCN
point names and allows the user to decide which points are dis-
played in the GENERICS points table under the local display.
Each one of these placeholders allows the input of an 8-character
ASCII string. Using a CCN interface, enter the Edit mode for the
Service-Config table "generics" and enter the CCN name for
each point to be displayed in the custom points table in the order
they will be displayed. When done entering point names, down-
load the table to the rooftop unit control.
IMPORTANT:
The
computer
(ComfortVIEW™, Service Tool, etc.) that is used to
interact with CCN controls always saves a template of
items it considers as static (e.g., limits, units, forcibil-
ity, 24-character text strings, and point names) after
the software uploads the tables from a control. There-
after, the software is only concerned with run time
data like value and hardware/force status. With this in
mind, it is important that anytime a change is made to
the Service-Config table "generics" (which in turn
changes the points contained in the GENERICS point
table), that a complete new upload be performed. This
requires that any previous table database be
completely removed first. Failure to do this will not
allow the user to display the new points that have been
created and the CCN interface will have a different
table database than the unit control.

START-UP

IMPORTANT: Do not attempt to start unit, even
momentarily, until all items on the Start-Up Checklist
and the following steps have been completed.
Check that unit has been installed in
Unit Preparation —
accordance with the installation instructions and applicable
codes.
Make sure that the economizer hoods have
Unit Setup —
been installed and that the outdoor filters are properly installed.
Ensure that all electrical connections
Internal Wiring —
in the control box are tightened as required. If the unit has
staged gas heat make sure that the leaving air temperature
(LAT) sensors have been routed to the supply ducts as required.
Accessory Installation —
accessories including space thermostats and sensors have been
installed and wired as required by the instructions and unit
wiring diagrams.
system
software
Check to make sure that all
Crankcase Heaters —
as long as there is power to the unit, except when the
compressors are running.
IMPORTANT: Unit power must be on for 24 hours
prior to start-up of compressors. Otherwise damage to
compressors may result.
Evaporator Fan —
ry-installed. See Tables 3-26 for fan performance. Remove tape
from fan pulley, and be sure that fans rotate in the proper direc-
tion. See Table 27 for motor limitations. See Tables 28 and 29
for air quantity limits. Static pressure drop for power exhaust is
negligible. To alter fan performance, see Evaporator Fan Per-
formance Adjustment section on page 132.
Use the following steps for the controls:
Controls —
IMPORTANT: The unit is shipped with the unit control
disabled. To enable the control, set Local Machine Disable
(Service Test
STOP) to No.
1. Set any control configurations that are required (field-
installed accessories, etc.). The unit is factory configured
for all appropriate factory-installed options.
2. Enter unit setpoints. The unit is shipped with the setpoint
default values. If a different setpoint is required use the
scrolling marquee, Navigator™ accessory or Service
Tool software to change the configuration valves.
3. If the internal unit schedules are going to be used config-
ure the Occupancy schedule.
4. Verify that the control time periods programmed meet
current requirements.
5. Using Service Test mode, verify operation of all major
components.
6. If the unit is a VAV unit make sure to configure the VFD
static pressure setpoint using the display. To checkout the
VFD use the VFD instructions shipped with the unit.
Verify gas pressure before turning on gas heat
Gas Heat —
as follows:
1. Turn off field-supplied manual gas stop, located external
to the unit.
2. Connect pressure gages to supply gas tap, located at field-
supplied manual shutoff valves.
3. Connect pressure gages to manifold pressure tap on unit
gas valve.
4. Supply gas pressure must not exceed 13.5 in. wg. Check
pressure at field-supplied shut-off valve.
5. Turn on manual gas stop and initiate a heating demand.
Jumper R to W1 in the control box to initiate heat.
6. Use the Service Test procedure to verify heat operation.
7. After the unit has run for several minutes, verify that
incoming pressure is 6.0 in. wg or greater and that the
manifold pressure is 3.5 in wg. If manifold pressure must
be adjusted refer to Gas Valve Adjustment section on
page 141.
7
Crankcase heaters are energized
Fan belt and fixed pulleys are facto-

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