INTRODUCTION:
The Birdwell environmental control units were originally designed
for world-wide use on offshore oil drilling and producing platforms. In
approximately twenty years of use in this harsh environment, the rugged
corrosion resistance and reliability of the systems were proven to be significantly
superior to the units that were designed for commercial and residential
use. Since that time, users such as refineries, steel mills, chemical plants,
pulp and paper plants and others having similar problems with corrosion
and/or hazardous conditions have found the Birdwell environmental control
systems to be tough and dependable.
The fundamental guidelines used in designing the systems were unrestricted
serviceability and ease of installation. Also of prime importance were
reliability, safety and resistance to corrosion. As a result of this criterion,
many believe these to be the finest units available for the intended market.
All cabinets and other sheet metal parts are constructed of not less
than 16 gauge stainless steel (doors are double wall). Parts most subject
to corrosion such as drain pans and exterior grilles are furnished in stainless
steel as standard. Coils
and piping may be coated with optional epoxy or high bake phenolic. The
units are available in several explosion proof configurations. For a complete
list of standard features and options, see the applicable brochure.
INDOOR OR OUTDOOR INSTALLATION:
Before installing the vertical unit, check with the building manufacturer
and any applicable building codes. Refer to BAC brochure for physical and
dimensional data.
A level foundation or platform is required for proper operation of
the vertical unit. A Non-level location may disrupt proper draining and
possible water damage may follow.
RIGGING AND PLACEMENT:
The packaged self contained BAC unit has lifting eyes at the side
of the unit for convenient rigging. The eyes are bolted to the side of
the unit near the top. With the help of a forklift the unit may be located
with ease.
POSITIONING:
Unit condenser air inlet and outlets may be located in any direction
as the unit is not affected by wind direction. Provide adequate clearances
around and above the unit for unrestricted air flow, safety and service
access.
INSTALLATION:
CAUTION: Before making any electrical connections or performing
any maintenance, make sure all power switches pertaining to this equipment
are turned off and locked. In additional to the danger of electrical
shock, the fan motors have internal overload protection that could restart
a fan without warning and cause serious injury! Also, before energizing
any of the electrical equipment or making the initial start up of the system,
make certain the ambient atmosphere is safe (non-hazardous).
Consult local codes or ordinances for specific requirements regarding
installation and the termination point of the condensate drain. A trap
is installed in the drain line inside the unit to prevent the entrance
of outside air.
If the unit is in a hazardous (classified) location, the drain must
be extended to a safe location to preclude the possibility of the trap
drying out in the heating season and allowing the entrance of contaminated
air.
ELECTRICAL:
Field wiring must comply with the latest applicable articles of the
National Electrical Code and the requirements of the United States Coast
Guard in the case of offshore drilling/producing platforms or ocean going
vessel use. Wiring should be performed only by a qualified electrician.
In hazardous locations install and pour seals between the unit and
all connecting conduit. Refer to articles 500 and 501 in the National Electrical
Code for specific requirements.
Size conductors using the data supplied on the nameplate. Use only
copper conductors. Be certain the available voltage matches the data on
the nameplate. A disconnecting means must be within sight and readily accessible
from the unit.
The unit must be securely grounded to the grounding lug provided
in the main control panel.
Thermostat connections are low voltage (24 volts). Refer to the unit
wiring schematic and the thermostat instruction sheet.
The thermostat is one stage cooling and one stage heating type (if
optional heaters are ordered with the unit). The unit may be equipped with
a built-in mechanical or programmable thermostat.
The thermostat (if purchased with the built-in option) is located
in the evaporator section behind the evaporator access door and can be
reached through a hinged locking door to prevent tampering.
DUCTING:
The duct system should be installed in accordance with the American
Society of Heating, Refrigerating And Air Conditioning Engineers, Inc.
(ASHRAE) standards. A filter grille is mounted in the front of the unit.
It contains a minimum 1" thick disposable fiber glass filters. Supply
duct may be connected to the top of the unit for normal duct installation.
An optional factory installed air distribution plenum may be furnished.
SCOPE OF OPERATION:
All Birdwell Model BAC series of air conditioning units are single
package self contained systems. These systems are designed for one or two
stage cooling (depending upon the model) and optional one or two stage
electric heating.
After the unit, ductwork, low and high voltage wiring have been installed
and the thermostat in place, set the thermostat system switch to the "off"
position and the fan switch to the "auto" position. Then switch
the main power to the unit on after referring to the "caution"
paragraph under the installation heading.
During cold weather, do not start the unit for a period of twenty-four
hours to allow time for the compressor crank case heater to vaporize any
liquid refrigerant that may have accumulated in the crank case during storage. CAUTION: Failure to observe this precaution could result in serious
damage to the compressor valves and/or bearings. After the twenty-four
hour period has elapsed the unit may be started in the cooling mode.
START UP PROCEDURE:
This procedure should be performed only by a qualified air conditioning
technician:
Step 1: Double check the voltage supplied to the unit to confirm
that it matches the nameplate requirements.
Step 2: Set the thermostat fan switch in the "on" position,
then check the unit to see if only the evaporator blower is running, then
set the switch back to the "auto" position.
Step 3: Set the thermostat system switch in the "cool"
position.
Step 4: Set the thermostat to a setting slightly below the indoor
temperature. Then check to see if the compressor is running.
Step 5: At this point amperage readings should be taken on the compressors
and motors to see if they conform to nameplate ratings.
Step 6: Set the thermostat system switch to the "heat"
position (if the unit has this option).
Step 7: Set the thermostat above the room temperature, then check
to see if the heat is operating.
Step 8: Set the thermostat system switch to the "auto"
position (if this option is present), then set for the desired operating
temperature.
MAINTENANCE:
NOTE: All maintenance should be performed by a qualified air
conditioning/heating mechanic.
MOTORS All fan and blower motors on the system are the sealed bearing
type and permanently lubricated, therefore no maintenance of the motors
is required.
BLOWERS The blowers and fans on the standard units are direct drive,
so there are no belts to service. It is recommended that at least once
a year (more often in very dirty locations) the blower wheel be inspected
and cleaned if necessary using a wire brush and vacuum cleaner.
FILTERS Filters should be checked at least once per month or more
frequently in dirty air conditions and cleaned or replaced as necessary.
COMPRESSOR The compressor is hermetically sealed and factory charged
with oil, so no maintenance is necessary.
CONDENSER/ The condenser coil should be checked and cleaned if found
nec-
EVAPORATOR essary) at least once a year (more often in dirty locations)
using a
COILS good commercial coil cleaning agent. This is very important
to maintain top efficiency and to prolong compressor life by keeping operating
pressures within normal limits. The evaporator coil should be inspected
at the same time and cleaned in the same manner if needed.
CONDENSATE The condensate drain pan and drain line should be checked
and
DRAIN cleaned (if necessary) at a minimum of twice yearly, or more
often if found to be necessary.
REFRIGERANT The system is factory charged with refrigerant and should
not re-
CHARGE quire adjustment. The sight glass will show some bubbling
in very hot or very cold conditions and is not necessarily indicative of
a need for additional refrigerant.
If at any time the system should need an addition of refrigerant,
it should be added very carefully and only by qualified personnel. Use
only refrigerant 22!
NOTE: Whenever maintenance is being performed on this equipment whereby
the refrigerant system may be opened up to the atmosphere, proper procedures
for handling system refrigerant must be followed according to the Environmental
Protection Agency (EPA). Please refer to Title 40 of the Code of Federal
Regulations, Part 82 for EPA regulations.
If the system is low on refrigerant and the system still has considerable
pressure, the entire piping circuit should be checked and the leak located
and repaired before any refrigerant is added.
If the system is completely void of pressure, it should be pressurized,
the leak located and repaired, then a new liquid line drier be installed.
After this is done, a good vacuum pump should be connected to the
system and a run for several hours to remove any possible moisture that
could be present. After the vacuum has been pulled, weigh in the proper
charge according to the data on the nameplate.
If any problem is encountered that is not covered in these instructions,
or for any question that might arise, call The Birdwell Company in Houston,
Texas: (281) 492-1786.
