Specifications
7
START-UP
Unit Preparation —
Check that unit has been installed in
accordance with the installation instructions and applicable
codes.
Unit Setup — Make sure that the economizer hoods have
been installed and that the outdoor filters are properly installed.
Internal Wiring — Ensure that all electrical connections
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 — Check to make sure that all
accessories including space thermostats and sensors have been
installed and wired as required by the instructions and unit
wiring diagrams.
Crankcase Heaters — Crankcase heaters are energized
as long as there is power to the unit, except when the compres-
sors are running.
Evaporator Fan — Fan belt and fixed pulleys are factory-
installed. See Tables 3-26 for fan performance and motor limi-
tations data. Remove tape from fan pulley, and be sure that fans
rotate in the proper direction. See Table 27 for motor limita-
tions. See Tables 28A and 28B for air quantity limits. Static
pressure drop for power exhaust is negligible. To alter fan per-
formance, see Evaporator Fan Performance Adjustment section
on page 110.
Controls — Use the following steps for the controls:
NOTE: The unit is shipped with the unit control disabled. To
enable the control, set Local Machine Disable (Service
Test
→
STOP)toNo.
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 set points. The unit is shipped with the set point
default values. If a different set point is required use the
Scroll 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 set point using the display. To checkout the
VFD use the VFD instructions shipped with the unit.
Gas Heat — Verify gas pressure before turning on 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.
IMPORTANT: Do not attempt to start unit, even
momentarily, until all items on the Start-Up Checklist
(in installation instructions) and the following steps
have been completed.
IMPORTANT: Unit power must be on for 24 hrs prior
to start-up of compressors. Otherwise damage to com-
pressors may result.