Bryant 379H User's Manual
Contents
1. The Bryant Model 450 379H is a heating unit designed for outdoor installation either rooftop or at ground level It is available with either of two factory in stalled direct expansion coils Model 180R or 240R 379 or with no expansion coil as Model 450 379H Model 180R units are equipped for use with R22 refrigerant and provide 180 000 Btuh cooling when connected with a Bryant Model 180 566 Condensing Unit Model 240R units are equipped for use with R500 refrigerant and provide 240 000 Btuh cooling when connected with a Bryant Model 240 566 Con densing Unit All three models have a heating input of 450 000 Btuh approximately for both natural and propane gas They are equipped with a two stage firing arrangement for operation at a reduced input of 225 000 Btuh Important Read Before Installing Be sure the available gas supply is the same as that shown on the American Gas Association A G A rating plate Check the electrical supply to be sure that voltage frequency and phase correspond to that specified on the unit rating plate Check all national state and local building codes af fecting the installation of this unit Check all local or dinances that could affect the installation of this type equipment WARNING All access panels must be in place at all times when unit is in operation GENERAL The design of the unit is certified by the American Gas Association A G A for use with natural or pro2. Natural Gas Unit The gas input should agree with that shown on the unit rating plate 450 000 Btuh The burners are equipped with fixed orifices The burners on the natural gas units are equipped with No 38 drill size orifices The following method may be used to adjust the input on natural gas units Water Manometer When using a water manometer to measure the mani fold pressure proceed as follows to adjust the gas in put 1 Turn off gas to unit Connect manometer to 1 8 inch pressure tap at outlet of gas valve 2 Turn on gas to unit With burners fired and both first and second stage gas valves open adjust the pressure regulator to obtain the correct manifold pressure as shown in Table II Check with local gas utility for Btu value and specific gravity of gas in the area TABLE Il Specific Gravity oso 061 0 63 0 67 _ Example Heating value of gas in the area is 1030 Btu Specific gravity is 0 62 a From Table II the manifold pressure required for 450 000 Btuh is 3 0 inches we b Set manifold pressure to 3 0 inches water column by adjusting gas pressure regulating screw If the required manifold pressure exceeds 3 3 inches w c or is less than 2 7 inches w c the orifices should be sized according to unit requirements CAUTION Do not redrill orifices under any circum stances Air Shutter Adjustment To adjust the primary air to each burner partial
3. cooling section starting procedure HEATING Follow the lighting instructions attached to the unit The sequence of control operation is as follows 1 Turn on electrical power and gas supply to unit 2 When pilot gas cock is opened gas flows to pilot and to pilot pressure switch Pilot pressure switch then closes to complete 24 Volt circuit Pilot then lights automatically The circuit is then completed through switching of first pilot to second pilot igniter coil automatically lighting second pilot After the pilots have been automatically lighted electrical po tential is available to first stage gas valve When thermostat calls for heating a circuit is completed be tween W1 and 4 This allows current to flow through first stage gas valve and fan switch If room tempera ture continues to drop second stage of thermostat will complete a circuit between 4 and W2 energizing second stage gas valve bringing unit to full power On setting room thermostat below room temperature both stages of firing will shut off Safety Pilot Test 1 If any one pilot should be extinguished switch ac tion of pilot will interrupt electrical circuit of first stage gas valve consequently unit will shut off 39379D35 2 To check this operation turn pilot gas valve off manually The pilots should re ignite automatically when pilot gas valve is turned on NOTE There will be a time interval or delay before the pilot coils will ignite the
4. pane gas with the appropriate controls and orifices The units are designed specifically for outdoor in stallation either at rooftop or ground level Installation of the unit consists of the following I Locating the Unit II Gas Piping III Duct Connection IV Venting V Coil Connection Models 180R and 240R 379H VI Electrical Connections VII Start up and Pe eue tS VIII Maintenance Installation Instructions OUTDOOR HEATING AND COOLING UNIT 379H Size 450 180R amp 240R Series D i 39379D35 1 3 72 A70191 Figure 1 SECTION I LOCATING THE UNIT Extreme caution should be observed to prevent dam age when moving the unit Maintain the unit in an up right position at all times during rigging and moving operations To facilitate lifting and moving opera tions place the unit in an adequate rope or ca ble sling CAUTION Protect the top and sides of the unit from possible damage from rigging sling Rooftop Installation Level the unit on a base situated a minimum of 6 in ches above the roof to insure proper drainage Consult local and state building codes for installation require ments Be assured the roof construction will support the weight of the equipment Ground Level Installation The unit should be placed on a level concrete slab 4 inch minimum thickness level the unit on the slab with 1 inch clearance to insure proper drainage Combustible Clearances Minimum clear
5. pilot again Limit Control 1 Bryant Model 379 is equipped with lower and up per limit controls 2 If lower limit opens first stage of automatic gas valve is de energized shutting off gas 3 If upper limit opens first stage of the automatic gas valve is de energized and the SPDT switching action of upper limit bypasses gas valves circuit and ener gizes fan delay relay and blower motor starts 4 Upper limit control has a dual function its primary action is to shut off the gas valve but it also energizes the blower motor if the furnace becomes overheated The recommended method of checking the limit con trols is to gradually block off the return air after the furnace has been operating for a period of at least 5 minutes As soon as the limit is proved safe the return air opening should be unblocked to permit normal air circulation By using this method to check the limit it can be established that providing the limit is func tioning properly it will fail safe if there is motor failure or overheating of the heating section of the unit Fan Relay The unit utilizes a fan delay relay located in the con trol box Upward movement of the adjustment lever causes a lengthening in the off cycle this results automatically in shortening the on cycle Down ward movement of the adjustment lever has the oppo site effect the off cycle is shortened the on cycle is lengthened Adjusting Gas Input
6. set at 0 8 amperes for the first stage and 0 4 am peres for the second stage Use thermostat assembly Bryant Part No 34427D57 782F and sub base assembly Bryant Part No 34427D59 Q672B NOTE Both thermostat and sub base assemblies are for heating only For field wiring diagram refer to Figure 3 39379D35 NOTE If aluminum conductors are used the connec tions must be made in accordance with the National Electric Code Aluminum wire connections must be made with special connectors In preparing the wire just before installing the connector all aluminum wire must be brush scratched and the wire coated with a corrosion inhibitor such as Pentrox A When it is suspected that the connection will be exposed to moisture it is very important to cover the entire con nection completely to prevent an electro chemical ac tion that will cause the connection to fail very quickly Reducing the effective size of the wire such as cutting off strands so that the wire will fit a connector is very poor practice Proper size connectors should be used SECTION VII START UP AND ADJUSTMENTS Before starting the unit make sure that the gas pipe is purged and free from air Do not purge into the com bustion chambers All gas piping connections should be leak tested WARNING Do not use an open jsme to lekir Use a soap and water solution Start Up COOLING Refer to appropriate Bryant Model 566 installation instructions for
7. ances are 6 inches from rear or duct side 24 inches on all other sides and 0 inch on the bottom These clearances permit the use of combus tible materials for supports The top of the unit must be kept clear at all times UNIT CONNECTION SIZE SIZE COIL 7 8 OD Suction 2 eaf 6 3 16 i 14 13 16 afl 180R 379H 5 8 OD Liquid 2eal 103 16 18 13 16 ae gone a ae Suction 2ea 7 3 16 12 5 8 pf tose 1812 Refer to condensing unit for compressor suction and liquid line sizes 5 8 OD Liquid 240R 379H Approximate Shipping Weights 450 379H 1425 Ibs 180R 379H 1460 Ibs 240R 379H 1565 Ibs DIA ELEC SINLET GAS CONN OPPOSITE SIDE f ie BAFFLE P N68347D SEPT DRAIN CONN 7 G Ms 4 OPPOSITE SIDE leg 6 A69420 Figure 2 Dimensional Drawing TABLE l Ratings and Capacities 225000 Se a a 730 608 Full Load Curo mwe a a Locked Rotor Current ams 2 so a e Branch Circuit Wire Sze Mne mwem n a Brenon Crow Fuse See Max Amps o o o Filters 450 379H 6 16x25x1 180R amp 240R 3 16x25x1 3 20x25x1 If aluminum conductors are to be used the connections must be made in accordance with the National Electric Code The wire size selected must have a current capacity not less than that of the copper wire specified and must not create a voltage drop between the servi
8. ations WARNING Never use a match or other open flame SECTION ili DUCT CONNECTIONS Before ductwork can be attached to the unit remove the panels located over the outlet and the return air opening The ductwork may be screwed or bolted to the unit flange with suitable gaskets to insure a weathertight seal Be sure that the sheet metal over laps the flange on the unit NOTE When using Bryant plenum package the up per skirt of the plenum should be placed up and under top cover of the unit then sealed properly All duct work external of the structure must be properly insu lated and waterproofed All openings in the structure must be properly flashed in accordance with local codes and good building practices The supply and re turn ductwork should be provided with an approved vibration eliminator NOTE The vibration eliminator must be located within the structure SECTION IV VENTING The vent cap assemblies including three sheet metal angles are packaged in the gas control compartment Installation of these assemblies is as follows 1 Remove the discard cover on each of vents on roof of unit 2 Remove top plate from each vent cap assembly by removing four retaining screws 3 Use screws supplied with assemblies to fasten base section of vent cap assembly to vent section top cover plate unit top is drilled to receive these screws 4 Reattach top cover plate removed in Step 2 above 5 Remove three self ta
9. ce panel and the unit in excess of 2 of the unit rated voltage 39379035 ay ee SECTION Il GAS PIPING A separate gas supply line should be installed to run directly from the meter to the heating section Check your local utility for recommendations concerning existing lines Choose a supply pipe large enough to keep the pressure loss as low as practical Never use pipe smaller than the gas connection to the heating section Observe local codes for all gas pipe in stallations The following are pertinent recommendations 1 Avoid low spots in long runs of pipe It is best to grade all pipe 1 4 inch in every 15 feet to prevent traps All horizontal runs should grade downward to risers Risers should be used to connect to heating section and to meter 2 Install drip leg in riser leading to heating section Drip leg will function as trap for dirt and condensate Drip legs should be installed where condensate will not freeze 3 Install manual shutoff valve in gas supply pipe near heating section where it can be easily reached 4 Install ground joint union close to furnace between gas controls manifold and manual shutoff valve 5 Support all piping with appropriate hangers etc Use a minimum of one hanger every 10 feet 6 Use joint compound pipe dope that is resistant to action of propane gas 7 After all connections are made use soap and water solution to check for leaks or method specified by local utility regul
10. ly close the air shutter until there is a slight yellow tip on the top of the flame then open the air shutter until the yellow tip just disappears This should be done af ter the burners have been operating at full input for 5 or 10 minutes approximately Temperature Rise Models 450 379H 180R and 240R 379 are designed for operation within a temperature rise range of 20 F to 75 F against an external static pressure up to 1 0 inch water column l NOTE Temperature rise is the difference between the temperature of the air in the return air duct and the temperature of the air in the discharge duct near the heating section l SECTION VIII MAINTENANCE Lubrication Refer to the rating plate for the blower motor lubrication requirements Cleaning the Heating Unit 1 Be sure that main line disconnect switch is in OFF position TAG SWITCH WITH SUITABLE WARNING LABEL Remove front access panel Turn off manual gas valve and pilot valve Disconnect pilot and escapement tubing Remove burners Remove flue baffle retainer and the flue baffles Clean flue passages with suitable brush O N Dm amp A QN Reassemble furnace by reversing above procedure making sure all seals are reinstalled properly 9 Check belt conditions and for proper belt tension 1 2 inch deflection Filter Filters in Models 240R and 450 379H are of the permanent type and should be inspected and cleaned at regular inter
11. pping retaining screws located approximately 7 inches behind each vent cap from unit cover Fasten sheet metal angle from each vent cap use retaining screws previously removed SECTION V COIL CONNECTION 180R amp 240R 379 1 Refer to condenser installation sheet for coil con nections of R Models NOTE Coil connections are sealed and seals should not be broken until just im mediately before making connections to condenser unit SECTION VI ELECTRICAL CONNECTIONS IMPORTANT Before proceeding with the electrical connections check the power supply to be sure that the voltage frequency and phase correspond to that specified on the unit rating plate All electrical connections must be made in accordance with the National Electrical Code and local codes governing such wiring The field connections must be made in accordance with the wiring diagrams in cluded in this instruction see Figures 3 and 4 A separate electrical line should be run for this installa tion and it should contain a fused disconnect switch placed in a convenient location For maximum fuse and minimum wire sizes refer to Ratings and Capaci ties Table Field wiring connections are made in the control box located in the gas control compartment of the unit Wiring entrances are made to the control box through knock outs provided in the casing All wiring entrances to the unit must be weatherproof and watertight The thermostat heating anticipator should be
12. vals Filters used in Model 180R 379H are of the disposable type and should be inspected and replaced with filters of the same type and size In spections should be made on a regular basis the time interval between inspection will depend on the type of application 39379D35 ae t a WR te Olt ee PDI 8 at cameos sesso ew es we Larter ee tee ee FACTORY WIRING ee FIELD WIRING 39373D35 OMA DAH WY ee oe WON Fr MECHANCIAL CONNECTIONS FAN SWITCH ON AUTO HEAT OFF COOL SYSTEM SWITCH 1M OD OOOHOO THERMOSTAT 34427D57 872F SUBBASE 34427 D59 Q672B UNIT LOW VOLTAG TERMINAL STRIP Figure 3 Field Wiring Low Voltage Models 450H 180R 240R 379 Blower Motor Contactor Cooling Fan Relay Delay Heating Relay Transformer Gas Pressure Switch Resistor 733 Automatic Pilot Limit Switch Ist Stage Gas Valve Secondary Limit Switch 2nd Stage Gas Valve Motor Overloads Figure 4 450 379H Series C 208 or 230 Volt 60 Hertz 3 Phase zos B71459 A70202
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