explosion proof air conditioning 

 

       Birdwell

      BIRDWELL MODEL BTB

      WALL MOUNT AIR CONDITIONING SYSTEMS

      INSTALLATION, OPERATION, AND MAINTENANCE INSTRUCTIONS

       

      INTRODUCTION:

      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 units that were designed for commercial and residential use. Since that time, users such as refineries, steel mills, chemical plants, pulp and paper plants, ocean going vessels 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 type 304 stainless steel (doors are double wall) as standard. Parts most subject to corrosion such as drain pans and exterior grilles are furnished in stainless steel as standard. Coil coating options include high bake phenolic or epoxy-ester. The units are available in several explosion proof configurations. For a complete list of standard features and options, see the applicable brochure.

       

      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 addition to the danger of electrical shock, the fan motors have internal overload protection that could restart a fan without warning and cause serious injury!

      Consult local codes or ordinances for specific requirements regarding installation and the termination point of the condensate drain. A trap is already installed in the drain line to prevent the entrance of outside air.

       

       

      RIGGING AND PLACEMENT:

      Provide a wall opening for the supply/return air sleeves. Allow 1/4" for clearance. Make sure the opening is squared. See product drawing for unit dimensions and installation details.

      Install foam gasket material around the sleeve to seal between the sleeve and the wall.

      The unit may be bolted to the wall using the wall mounting angles and (if deemed necessary) set on a user supplied support frame. In any case, be sure the wall anchoring system or the support is of sufficient strength to support the unit weight.

      The packaged, self contained BTBX unit has lifting eyes at the top for convenient handling.

       

      POSITIONING:

      Unit condenser air inlet and outlets may be located in any direction as the unit is not affected by wind direction. Provide adequate clearance around and above the unit for unrestricted air flow, safety and service access.

       

      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. An electrical disconnect must be within sight from and readily accessible from the unit. The unit must be securely grounded.

       

      OPERATION:

      If the installation is made during cold weather, do not start the unit for a period of a few 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.

       

       

      START UP PROCEDURE:

      Step 1: Double check the voltage supplied to the unit to confirm that it matches the nameplate requirements. For 3 phase models, check fan and blower rotation direction. If not correct, switch any two leads on power supply.

      Step 2: Set the thermostat to a setting above the room temperature, then turn the system switch to the "cool" position.

      Step 3: Set the thermostat to a setting below the room temperature to start the compressor.

      Step 4: Set the thermostat to a setting below the room temperature, then turn the system switch to the "heat" position.

      Step 5: Set the thermostat to a setting above the room temperature to start the electric heat.

      Step 6: If optional outside air stack, return air grille with damper and magnehelic gauge are purchased, set building pressure by opening or closing return air damper.

      NOTE: The thermostat and system switch power is supplied by intrinsically safe relays which allow the use of open (non-explosion proof) contacts in hazardous (classified) locations.

       

      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,

      AND FANS therefore there are no belts to service.

      FILTER The filter should be checked at least once per month or more frequently in dirty air conditions and replaced as necessary.

      COMPRESSOR The compressor is hermetically sealed and factory charged with oil. No maintenance is necessary.

      CONDENSER/ The condenser coil should be cleaned at least once a year (more

      EVAPORATOR often in dirty locations) using cleaning agent. This is very impor-

      COILS tant 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 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 should 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.