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

START-UP
IMPORTANT: Do not attempt to start unit, even
momentarily, until all items on the Start-Up Checklist
(at the back of this book) and the following steps have
been completed.
IMPORTANT: The unit is shipped with the unit control
disabled. To enable the control, set Local Machine Disable
(Service TestSTOP) to No.
Unit Preparation — Check that unit has been installed in
accordance with the installation instructions and applicable
codes. Make sure that the economizer hood has 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 LAT (leaving air temperature)
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 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 — Fan belt and fixed pulleys are factoryinstalled.
See Tables 3-24 for fan performance. Remove tape
from fan pulley, and be sure that fans rotate in the proper
direction. Static pressure drop is shown in Table 25. See
Tables 26-28 for motor limitations.
FIELD-SUPPLIED FAN DRIVES — Supply fan and power
exhaust fan drives are fixed-pitch, non-adjustable selections, for
maximum reliability and long belt life. If the factory drive sets
must be changed to obtain other fan speeds, consult the nearest
Browning Manufacturing Co. sales office with the required new
wheel speed and the data from Physical Data and Supply Fan
Drive Data tables (center distances, motor and fan shaft diameters,
motor horsepower) in Installation Instructions for a
modified drive set selection. For minor speed changes, the fan
7
sheave size should be changed. (Do not reduce the size of the
motor sheave; this will result in reduced belt horsepower ratings
and reduced belt life.) See page 141 for belt installation
procedure.
Controls — Use the following steps for the controls:
IMPORTANT: The unit is shipped with the unit control
disabled. To enable the control, set Local Machine Disable
(Service TestSTOP) to No.
1. Set any control configurations that are required (fieldinstalled
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
scrolling marquee, Navigator display, or CCN interface
to change the configuration values.
3. If the internal time schedules are going to be used, configure
the Occupancy schedule.
4. Verify that the control time periods programmed meet
current requirements.
5. Use Service Test mode to verify operation of all major
components.
6. If the unit is a VAV unit make sure to configure the static
pressure set point. To check out 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 fieldsupplied
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 all heat stages of
operation.
7. After the unit has run for several minutes, verify that
incoming pressure is 5.0 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 163.