Crankcase Heaters; Evaporator Fan; Controls; Gas Heat - Carrier Weathermaster 48P030-100 Controls, Start-Up, Operation, Service, And Troubleshooting

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 factory-installed. See Tables 3-25
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 26. See Tables 27-29 for motor limitations.
FIELD-SUPPLIED FAN DRIVES
Supply fan and power exhaust fan drives are fixed-pitch, non-ad-
justable 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
sheave size should be changed. (Do not reduce the size of the mo-
tor sheave; this will result in reduced belt horsepower ratings and
reduced belt life.) See page 161 for belt installation procedure.

Controls

IMPORTANT: The unit is shipped with the unit control disabled.
To enable the control, set Local Machine Disable (Service

Test STOP) to No.
Use the following steps for the controls:
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
scrolling marquee, Navigator™ display, or CCN interface
to change the configuration values.
3. If the internal time schedules are going to be used, config-
ure the Occupancy schedule.
4. Verify that the control time periods programmed meet cur-
rent 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 gauges to supply gas tap, located at
field- supplied manual shutoff valves.
3. Connect pressure gauges 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.
Connect 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 "TWO-STAGE GAS VALVE
ADJUSTMENT" on page 183.
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