Bard FH085D36D Installation Instructions Manual

Bard FH085D36D Installation Instructions Manual Manual pdf 20 page image

Manual 2100-392Page 18IMPORTANTDo not set the blower “on” set point lever ofthe combination fan/limit control above 150.LOUVERS AND GRILLESIn calculating free area for above ventilation andcombustion air requirements, consideration shall begiven to the blocking effect of louvers, grilles, orscreens protecting openings. Screens used shall not besmaller than 1/4 inch (6.3 mm) mesh and shall bereadily accessible for cleaning. If the free area througha design of louver or grille is known, it shall be used incalculating the size opening required to provide the freearea specified. If the design and free area is not known,it may be assumed that wood louvers will have 30-35percent free area and metal louvers and grilles will have60-75 percent free area.VENTINGThe flue pipe to the chimney must be the same size asthe flue outlet of the furnace, have no reductions, be ofa corrosion-resistant material, and have an upward pitchof 1/4” for every foot of horizontal run. A barometricdamper is supplied with the furnace and should beinstalled in the flue pipe observing the instructionspackaged with the damper control. The barometricdamper opening must be located in the sameatmospheric pressure zone as the combustion air inlet tothe furnace. This furnace must not be vented into thesame chimney with any solid fuel burning appliance.Masonry chimneys must be lined with a listed system orother approved material that will resist corrosion,softening, or cracking from flue gas at temperatures upto 1800° F. See Standard for Installation of Oil BurningEquipment NFPA31 and Standard for ChimneysNFPA211 for additional information.THERMOSTATNOTE: FC models do not wire directly to theprimary control. See wiring diagram onPage 33.These furnaces are designed to be controlled with any24V heating or heating/cooling thermostat. Theheat/cool thermostats must be designed for independentheat/cool transformer circuits to assure that the 24Vtransformer built into the oil primary control does notconflict with the main furnace 24V transformer. Theheat anticipator should be set at 0.20A. This is anominal setting. The thermostat circuit should bechecked to verify setting.FAN AND LIMIT CONTROLThe fan and limit control is factory installed in all units.See Table 13 for factory settings. The fan on/offsettings may have to be varied due to the static pressureimposed upon the system. The limit control is factoryset at maximum fixed stop allowable and must not bereset.When the installation is completed, measure the airtemperature in the discharge plenum and return airplenum. The temperature rise across the unit shouldfall within the “Rise Range” as shown in Table 13. It isnormally desirable to operate in the middle of the rangeunless air conditioning or other installationrequirements make that unfeasible. The speed of theblower may have to be either increased or decreased toobtain this temperature. The blower is equipped with a3 or 4 speed motor to make these adjustments.The fan and limit control in the burner compartmentgoverns the blower operation by means of twotemperature selections. One lever is set at 140 degreesfor example to start the blower, and the other lever is ata lower temperature, 110 degrees to stop the blower.These settings may be varied to suit the homeowner’scomfort. A greater temperature difference betweensettings may result in less repetition of the bloweroperation at the end of the heating cycle. A low “off”temperature is recommended for longer bloweroperation as this keeps the air of the home in moreconstant circulation.NOTE: On model FC085D36D the blower “on”setting is timed to assure blower operation.This blower “on” setting cannot be adjusted.