A function of the current invention resides in the provision of a furnace which features a closed cabinet, one finish of which is preferably provided with contemporary air externally of the constructing or space being heated. In other phrases, if the realm being heated includes spray paint booths or comparable areas from which the air should be evacuated to outer environment, the outlet dampers may, if desired, by managed to change the air removed with heated incoming air by working these outlet dampers. The amount of air being exhausted from the unit depends upon the amount of air which is required to produce the necessary heat for heating the world. In the present arrangement, the heated air leaving the heating unit is controlled by dampers which may be manually controlled by adjustable management means, or which could also be routinely managed within the occasion the realm being heated is subject to the operation of exhaust followers which divert a portion of the air to the outer environment. The entering air strikes past a heater factor to which gasoline is supplied because the gasoline being expended, and where air is proportioned in sufficient quantity to mix with the gasoline to trigger virtually complete combustion.
A function of the present invention resides in the provision of a heater aspect able to admitting air, and profile dampers capable of admitting unheated air about the periphery of the heater. The strain differential on opposite sides of the burner is maintained in such a fashion that if a comparatively small quantity of heated air is required, the profile dampers will are likely to open in order that a higher amount of unheated air is admitted to combine with the heated air leaving the furnace.
An extra feature of the current invention resides in the availability of a machine of the kind described wherein air may be circulated via the furnace to the constructing to offer ventilation thereto when no heat is required. The arrangement is such that when no heat is required, air could also be circulated from the outer ambiance to the constructing by way of the furnace unit with out requiring the intermediate heating step.
The exhaust circumstances in trendy plants are always changing. The present machine is designed to guarantee the correct amount of air at all times. The current system employs a relentless velocity drive together with the burner unit by which a desired amount of air could move from which the air may be discharged into the world to be heated. The discharge or quantity dampers regulate the total amount of air delivered by altering the resistance within the system. Elements that effect the quantity of contemporary air needed to replace the exhausted air are wind direction, temperature, the situation of the filters, and the variety of exhaust fans being used.
The dampers that are located above and under the burner compensate for the change in air movement throughout the burner, and these dampers open or shut to maintain maximum combustion effectivity. In the current association, it is feasible to preset or dial any volume if air desired from the discharge dampers from 30 p.c of capacity to 1 hundred of capacity of the air-circulating followers.
When the amount of air being delivered to the world to be heated modifications, so does the airflow and pressure drop throughout the burner. A delicate constant controller detects the change in airflow and automatically resets the profile damper plates that are above and beneath the burner unit, to insure most combustion effectivity. The present device operates at its peak efficiency with 0.22 inches of air resistance throughout the burner.
The profile dampers positioned by the fixed pressure control additionally compensate for clogged filters that create added resistance, wind course that effects the amount of air being handled, and compensate for pressure changes caused by various burner efficiency always. Consequently, the machine cuts heating and electrical value, and allows management to be successfully maintained.
These and different objects and novel options of the current invention shall be extra clearly and totally set forth in the next specification and claims .
In the drawings forming part of the specification.
FIG. 1 is a plan view of the furnace displaying the general arrangement of elements therein.
FIG. 2 is a vertical sectional view by means of the furnace unit, the position of the part being indicated generally by the line 2-2 of FIG. 1.
FIG. Three is a perspective view of the burner unit.
FIG. Four is a wiring diagram showing the way through which the device functions.
FIG. 5 is a cross-sectional view by means of the burner.
FIG. 6 is a perspective view of 1 end of the burner extrusion before the sealing end plates are hooked up thereto.
FIG. 7 is a diagrammatic view of the gasoline system of the burner feeding fuel to the pilot and predominant burners.
FIG. 1 of the drawings indicates a usually rectangular outer housing 10 which is related at its inlet finish with a filter part eleven by which the incoming air might move. While the inlet end of the furnace housing is shown as being open, this finish of the furnace is normally related by suitable duct work to the outer environment in order that the air entering the furnace is normally outdoors air drawn from the exterior of the constructing to be heated.
As is indicated in FIGS. 1 and three of the drawings, a panel 12 extends throughout the furnace housing between the sidewalls, between the sidewalls 13 and 14 thereof, and between the highest wall 15 and bottom wall 16. The panel 12 is apertured as indicated at 17, and a flange 19 which extends parallel to the sidewalls thirteen and 14 extends forwardly from the panel 12 on one side of the aperture 17, and a flange 19 extends forwardly from the panel 12 along the alternative facet of the aperture 17. The flange 19 ideally is supplied with a right angularly extending baffle flange 20 which is directed toward the sidewall thirteen and acts to protect the profile damper motor and the pressure sensor from direct contact with the heated air.
A pair of shafts 21 and 22 extend transversely across the apertures 17 near the higher and decrease edges thereof respectively. These shafts 21 and 22 help profile dampers 23 and 24 respectively which are rotated in unison by the damper motor. Crank arms 25 and 26 are provided on the shafts 21 and 22 respectively, and these crank arms are connected by links 27 and 29 to an arm 30 mounted upon the drive shaft 31 of the profile damper motor 32. Rotation of the drive shaft 31 in a single route tends to pivot the dampers 23 and 24 into substantially parallel relation to the vertical panel 12. Rotation of the drive shaft 31 in the opposite path is able to shifting the dampers 23 and 25 into absolutely open place at right angles to the vertical position thereof. The place of the dampers 24 and 24 determines the proportion of air entering the housing 10 which passes by means of the heater unit which is indicated on the whole by the numeral 33 to the whole quantity of air circulated.
The burner aspect includes an elongated extrusion 34 which is supported by appropriate bracket means, not illustrated within the drawings, by the sidewalls thirteen and 14 of the housing 10. The extrusion 34 is of typically rectangular cross part and is hollow, (See FIGS. 5 and 6 of the drawings, the extrusion 34 consists of substantially parallel high and backside walls 39 and 40, a rear wall 41, and a front wall 42. The downstream side of the burner aspect is supplied with a row of openings forty three which talk with the upper manifold 35, and a second row of apertures forty four that are in communication with the lower manifold 36. Fuel provide strains resembling 45 provide fuel to the higher manifold 35 whereas an identical fuel supply line is related to the lower manifold 36. The gasoline in the manifold 36 is often below relatively low pressure and the fuel leaving the manifold 36 by means of the outlet apertures forty four are normally of low flame capability and serve mainly as pilot burners for the gas flowing through the discharge openings forty three connected to the higher manifold 35. The gasoline flowing by the upper manifold 35 is under comparatively high stress, and is often turned on and off intermittently to heat the air flowing from the furnace. 5 and 6), the extrusion including an higher manifold 35 and a lower manifold 36 separated by a partition wall 37. As is indicated in FIGS.
As indicated in FIGS. 1 and 5 of the drawings, the extrusion 34 helps a pair of parallel end panels 45 and an intermediate partition plate 46. Prime panels 47 and a backside panel 49 mix with the top plates 45 and partition plate 46 to provide a generally rectangular passage means, the top and backside partitions of that are in spaced relation to the extrusion 34. A pair of apertured of foraminous baffle plates 50 and 51 are provided on the downstream facet of the extrusion 34. Each baffle 50 includes a vertical flange fifty two which is bolted or otherwise secured to the front flange fifty three of a corresponding top panel 47 by bolts fifty four or other suitable means. The baffle 50 contains an inclined portion 55 which is directed toward the vertical middle of the wall 44 of the extrusion and which is related at its lower finish 56 to a vertical flange 57 in spaced relation to the wall forty two of the extrusion 34. The vertical wall 57 terminates in a horizontal flange 59 which extends over the top wall 39 of the extrusion 34 and is secured thereto by bolts 60 or different appropriate means.
In an analogous method, the baffle 51 features a downwardly extending vertical flange 61 which is secured by bolts or different suitable means to the downturned vertical flange 63 of the underside panel 49. The flange sixty one is connected to an inclined portion 64 which is directed toward the vertical heart of the extrusion facet 41 and terminates in an edge sixty five which is in spaced relation to the higher baffle end 56 to supply a throat 66 therebetween. A downturned vertical flange 67 which is in spaced relation to the wall 42 of the extrusion 34 terminates in a horizontal flange 67 which extends beneath the wall forty of the extrusion 34 and is secured in place by way of capscrews 69 of different suitable means.
The flames caused by ignition of the gas passing by way of the apertures forty three speaking with the upper manifold 35 directed via the throat 66 between the baffles 50 and 51, and air compelled by way of the apertures within the baffles 50 and fifty one mix with the fuel to insure full combustion thereof. The flame heats the air as it’s drawn by way of the furnace housing.
It is going to be noted that the apertures 44 which talk with the low strain manifold 36 terminate inwardly of the vertical flange 67 of the decrease baffle fifty one so that the flames issuing from these apertures forty four are confined between the baffles and the extrusion.
The air is drawn via the housing 14 by way of a pair of axially spaced followers 71 which draw air from the housing 14 and direct the air by transversely elongated generally rectangular tubular outlet passages equivalent to seventy two mounted on the wall seventy three on the discharge finish of the furnace housing. The followers 71 are pushed by any suitable means, and are proven as mounted upon a typical shaft seventy four having a pulley or sprocket 75 thereon which is connected by a suitable belt or chain 76 to a cooperable pulley or a sprocket 77 on the drive shaft 79 of the drive blower motor 80. This arrangement could also be indicated in FIG. 1 of the drawings.
Every tubular outlet 72 communicates with an outlet aperture resembling eighty one within the housing panel 73. Each of the tubular retailers 72 is provided with a series of louvers eighty two mounted on parallel shafts 83 between the other sides of the tubular members 72. Arms 84 which rotate with the louvers eighty two are hingedly connected to a vertical link 85 to insure of pivotal movement of the louvers from open to closed position in unison. In view of the truth that the way by which a reversible motor akin to 87 could drive a shaft 87 to rotate the crank arm 86 in both direction is well-known within the artwork, the detail of this construction isn’t indicated. The working link eighty four is linked to a crank arm 86 pivotally supported at 87 and linked by appropriate linkage to a discharge damper motor 87 located between the outlet passages 72 as indicated in FIG. 1 of the drawings. By operation of the motor 87, the outlet or discharge dampers may be rotated from a totally closed place to a fully open place through which the louvers are parallel to the path of circulation of air by the outlet passages. Nonetheless, for example, the motor 87 could also be linked by belt or chain means to a pulley or sprocket on the shaft 87 to slowly rotate the shaft in both course.
The circuit by means of which the current device is operated is best illustrated in FIG. Four of the drawings. Beyond the fuse 90 from the present provide supply, a conductor 91 connects the road wires H and G together with a sign mild 92 which indicates that the facility is on, and which is illuminated when the circuit is energized through an acceptable fundamental switching association which isn’t illustrated in the drawings. The new line H is provided with a fuse 90 to protect the circuit. As is indicated on this figure, a circuit of usually 110–one hundred twenty volts is indicated with line wires H and G representing what is often identified in the trade as the hot line and the ground wire.
A conductor 93 extends from the road wire H to line wire G and features a transformer coil 94 of a transformer 95. The transformer 95 is designed to remodel the voltage from 110 volts between the line wires H and G to a decrease voltage equivalent to 24 volts within the secondary coil 96. One terminal of the coil 96 leads via a usually closed swap ninety seven to a conductor 99 leading to a time delay relay coil 100, the other terminal of which is connected by conductor one hundred and one to the other facet of the transformer secondary 96. In actual observe, the time delay relay includes a warp switch which opens after a predetermined length of time. Nonetheless, a time delay relay which accomplishes the same result’s illustrated.
The road wire H is directed to a manually operable change 102 which could also be positioned in the relation proven in FIG. 4 through the summer season months, and which could also be positioned in an alternate place during the winter months. In the actual arrangement illustrated, the swap 102 is in the summer season position and closes a circuit from the line wire H to the conductor 103. The conductor 103 is connected by means of a sign mild 104 to the road wire G to indicate that the circuit is closed. The conductor 103 additionally results in a low limit relay change 106. The aim of this arrangement will be later described.
As soon because the relay coil a hundred is energized, a switchblade 107 is closed closing a circuit from conductor 103 by a conductor 109 and the change 107 to a conductor 110 resulting in conductor 111 leading by way of a low restrict signal gentle 112 to the road wire G. The closing of the switch 107 additionally closes a circuit from line wire G. The closing of the change 107 also closes a circuit from line wire H, the conductor 109, change 107, conductors one hundred ten and 111 to a conductor 113 leading by way of a sequence of overload switches 114 to a conductor a hundred and fifteen connected to the primary of a transformer coil 116, of a transformer 118 the opposite terminal of which is related by conductor 117 to the road wire G. Thus the closing of the switch 107 robotically energizes circuits resulting in a differential stress change 32 designed to manage the position of the profile dampers on reverse sides of the burner items, and a damper motor 122 designed to control the place of the discharge dampers of the gadget. The damper motor 32 which controls the profile dampers may be the kind generally known as motor M 604 C produced by Honeywell of Minneapolis, Minnesota. The management unit 120 for the motor 119 is operated by differential pressure on opposite sides of the burner, and the numeral 120 indicates a differential stress change used to manage the motor 119.
The transformer 118 includes a secondary coil 121 which additionally controls the damper motor used to regulate the dampers at the discharge of the device. The motor 122 is a reversible kind motor controlled by a potentiometer 123. The various different elements of the circuit will likely be later described. In view of the truth that the switch 102 is indicated within the position to regulate the movement of unheated air during the summer time time, this association will first be described.
The motor 32 drives a rotatable shaft 124 which may eventually actuate either of a pair of limit switches 125. The coils of the motor are connected by these restrict switches 125 to contacts 126 and 127 which could also be engaged by a movable contact 129 actuated by the diaphragm gadget 130 which is subjected to the pressures P1 and P2 linked by conduits 131 and 132 to reverse sides of the burner factor. In different phrases, when the differential pressure exceeds certain limits, the movable contact 129 will interact one of the fastened contacts 126, 127 to maneuver the motor 32 an angular distance sufficient to vary the differential strain within the sensing unit 130 and to once once more middle the contact 129 between mounted contacts 126 and 127. On the other hand, if the differential pressure on reverse sides of the burner unit decreases sufficiently, the movable contact 129 will engage the opposite of the contacts 126, 127, and name for a reversal of the motor 32. As will probably be understood, motion of the motor 32 controls the opening and shutting of the profile dampers 23 and 24.
The motor unit controlling the outlet dampers eighty two is indicated usually by the numeral 87. The motor unit 87 features a rotatable motor unit 133, one terminal of which is linked by conductor 134 to the current provide. A condenser 135 is related throughout the remaining motor terminals, and these remaining terminals are connected by restrict switches 136 and 137 to conductors 139 and 140 which lengthen by coils 141 and 142 to a pair of contacts 143 and 144 on reverse sides of an armature 145. The armature 145 is controlled by movements of the plate 146. The armature 145 is connected by a conductor 147 to one facet of the transformer secondary 121.
The motion of the motor ingredient 133 is managed by the potentiometer 123 together with a resistance coil 149, one terminal of which is linked by the conductor a hundred and fifty to a coil 153 controlling the position of the plate 146 in a way to maneuver the contacts 145 into engagement with the contact 144. The opposite end of the potentiometer coil 149 is related by a conductor 155 to a coil 156 which tends to maneuver the member 146 in the opposite route and to trigger the contact arm 145 to have interaction the contact 143. The conductor 155 leads by a pair of auxiliary potentiometers 157 and 159 which will likely be later described.
A temperature actuated low restrict switch 160 is organized in shunt relation to the time delay relay swap 107. The low limit change 160 is about to open when the temperature of the incoming air is lower than a predetermined minimal equivalent to 40° F., and accordingly is closed during hotter weather. When the system is getting used to circulate air throughout summer season weather, the circulating fans should not perform if the surface temperature is under a minimal of perhaps 40° F. Nonetheless, the switch 160 is normally closed when the temperature is above the minimum desired. It ought to be defined which means are provided for holding the change 160 closed in the event the furnace is began in extremely chilly weather. As soon as the furnace has been started, the inside of the housing is maintained above the low limit temperature.
The circuit from line wire H passing by either of the switches 107 or 160 of the time delay relay 161 flows via the conductor 113 and the overload switches 114 to a conductor 162 leading to the damper end change 163. The louvers eighty two of the outlet damper usually shut when the operating motor 122 is deenergized. As quickly as present flows by means of the conductors 115–117, the transformer coil 116 supplying current to the motor 122, the louvers swing toward partially open place as determined by the potentiometer 123. The damper end swap 163 is bodily closed by the partial opening of the damper louvers, closing a circuit to the conductor 164 leading to the relay coil 165, the other terminal of which is linked by the conductor 166 to line wire G. The energization of the solenoid coil 165 closes a series of three starter motor switches leading to the blower motor 167 type the line wires L1 L2 and L3. A primary auxiliary switch 169 is also closed, and a circuit is supplied from a conductor 170 linked through the switch 102 to line wire H and to a conductor 171 main to allow limit relay 172, the other terminal of which is grounded at 173. Energization of the relay coil 172 capabilities to open the swap 97 within the circuit resulting in the time delay relay and to shut the switch 106 connecting the relay coil 172 by way of conductor 105 to the conductor 103. Thus the switch 106 closes a holding circuit for the relay coil 172 and this coil remains energized as lengthy as the auxiliary swap 169 controlled by the motor-beginning relay 165 is closed.
A secondary auxiliary switch 174 is closed by the motor relay coil 165, closing a circuit from the conductor 164 by way of a conductor 175 and a conductor 176 to a conductor 177 resulting in floor wire G through an indicating gentle 179 which indicates that the blower is in operation. A conductor 180 can also be linked to the conductor 164 and leads by way of an indicator light 181 to the bottom line G indicating that the dampers and damper motor 122 are in operation.
An additional component which functions is an air switch 182 linked between the conductor 177 energized by the closing of the second auxiliary swap 174 and which closes a circuit to the conductor 183 related to the bottom line G by an indicating light 184 which indicates that air is flowing by means of the furnace. The conductor 190 is connected to a conductor 191 via a usually closed low gas change 192 which is opened solely when the gasoline stress is just too low to assist combustion. The conductor 191 is related to the road wire G via a low fuel indicator light 193. The remainder of the circuit is broken between contacts 185 of guide swap 102. During winter weather, when the system is to function as a furnace, the switch 102 is moved downwardly from the place proven in FIG. Four of the drawings in order that the upper conductor 186 closes the contacts 187 previously linked by the swap blade or switch factor 189, and the change blade 189 connects the contacts 185. This closes a circuit to a conductor 190 leading to the remainder of the furnace apparatus circuit.
A conductor 194 is related to the conductor 191 to the road wire G by means of a usually closed high gas swap 195 and an indicator gentle 196 indicating that the pressure within the fuel line is not excessive. The change 195 is only opened when the gasoline strain exceeds a predetermined maximum.
A conductor 197 is connected to the conductor 194 between the high gasoline change 195 and the indicator light 196 and extends by means of a excessive limit swap 199 to a conductor 200 leading to the road wire G by means of an indicator gentle 201 indicating that the excessive restrict switch 199 is closed. The control 204 closes an internal circuit from the power terminal 203 to a terminal 206 related by conductor 209 to the relay change 210 of a nonrecycling relay 211 to a conductor 212 leading to the first coil 213 of an ignition transformer 214. The other transformer coil is connected by means of conductor 215 to ground wire G. Alternatively, the management 204 could also be a considerably similar management produced by Minneapolis Honeywell of Minneapolis, Minnesota known as Management R 890 G. The control 204 is connected to a scanner 205 able to figuring out the presence of ignition flame to offer the presence of flame by the use of an ultraviolet sensitive gasoline discharge tube and which opens the circuit to the main gas valve and to the pilot valve in the occasion no flame is detected after predetermined time interval. A conductor 202 is related to the conductor 200 and provides current by way of a terminal 203 of a industrial flame safeguard control which is shown diagrammatically within the drawings. The management 204 includes a UVM-1 management produced by the Combustion Control Division of the Electronics Corporation of America positioned at Cambridge, Mass.
The secondary coil 216 of the ignition transformer 214 has one end grounded as indicated at 217, and extends to a spark plug 219 able to igniting the gas for the furnace.
The terminal 206 of the control 204 can also be connected by a conductor 200 related to the bottom wire 6 via the signal gentle 221. The conductor 220 is designed to energize the pilot valve 222 related by means of conductors 223 to floor wire G. Thus the pilot valve 222 is opened concurrently with the operation of the ignition spark plug 219, and capabilities to turn on the pilot flames and to ignite the fuel.
When a flame is detected by the scanner 205, a circuit is closed from the ability terminal 203 of the management 204 to the terminal 207 via an inner circuit. The terminal 207 is related by a conductor 224 resulting in an indicator gentle 225 which is also related to the ground wire G. The coil of a major gasoline solenoid valve 226 is connected in parallel with the detector mild 225 by conductor 227 and is energized when the terminal 207 is energized.
A conductor 229 is connected to the terminal 207 by means of a portion of the conductor 224 and leads through a normally closed relay switch 230 through a conductor 231 resulting in the coil 232 of the nonrecycling relay 211. The other terminal of the coil 232 is linked by conductors 233 and 234 to ground wire G. Thus the relay 232 is energized when flame is detected by the sensor 205 opening the circuit to conductor 212 leading to the ignition transformer and shutting a circuit to a contact 234 main by means of the relay coil 232. As soon as the relay disengages the ignition transformer 213, it must be manually reset.
The facility transformer 95 which is linked between the line wires H and G has its secondary coil 96 connected by conductors 236 and 237 to terminals 239 and 240 of a modulating management motor 235 which could also be of the kind designated as M 931 C made by Minneapolis Honeywell of Minneapolis, Minnesota. The circulation of gasoline can also be managed by a proportional management 243 of the kind known as a T92 A thermostat which is also produced by Minneapolis Honeywell. The reversible motor factor 241 of this motor opens and closes a valve in the main gasoline line in order to increase and decrease the move of fuel to the burners depending upon present situations. In view of the fact that these units are well-known in the art, it is believed sufficient to say that the move of fuel through the main valve to the burners is regulated by the models 242 and 243 to offer a proper move of gas and to supply a desired ambient temperature. The motor unit 235 is controlled by a remote bulb proportional temperature controller produced by Minneapolis Honeywell of Minneapolis, Minnesota.
The motor unit 235 and its controls 242 and 243 are set into operation via a change 244 in the motor and management circuit. A conductor 245 leading to the conductor 244 and by way of which current flows when the scanner 205 indicates the presence of a flame closes the circuit to a relay coil 246 the opposite terminal of which is grounded at 247. Activation of the coil 246 closes the change 244 to set the motor unit 235 and its controls in operation.
For the aim of identification, it should be famous that the motor 122 which controls the dampers in the discharge of the furnace may be of the kind referred to as M 905 E additionally produced by Minneapolis Honeywell Obviously, equal units could be employed.
FIG. 7 of the drawings indicates diagrammatically the association of valves in the gasline. The fuel supply line 250 features a manually operable plug valve 251 which may close off your entire system. A bypass line 252 offers a fuel provide to the pilot burners by way of a plug valve 253 and a pressure regulating valve 254. The low strain gasoline passing through the valve 254 passes by way of the solenoid valve 222 and to the pilot manifold of the burner.
The operation of the machine is believed fairly evident from the foregoing description. The closing of the blower motor starter switch additionally closes an auxiliary change 169 finishing a circuit through a switch 102 from line wire H by means of conductors 170 and 171 to a low limit relay coil 172. This opens the circuit to the time delay relay coil a hundred and closes a holding circuit which maintains the relay 172 energized as lengthy as the blower motor is in operation. The second auxiliary switch 174 closes a holding circuit to the motor-starting relay 165 maintaining the blower motor in operation as long because the overload safety switches 114 and the thermostatically operated swap 160 are closed. Through the summertime, when it is desired to circulate outdoors air via the area to be heated, the swap 102 is positioned in its elevated place shown, bridging the contacts 187. Current flows by the transformer 95 and a circuit is closed by the switch 97 of the low restrict relay to the time delay relay coil 102. A circuit is then closed from line wire H through the switch 102 and swap 107 of the time delay relay by means of the conductor 113 and the usually closed overload switches 114 to the conductors a hundred and fifteen and 117 finishing the circuit to the transformer 118 providing power to the discharge damper motor 122 and the profile damper motor 32. The motor 122 strikes the dampers from their normally closed place to a position as decided by the setting of the potentiometer 123. When the louvers 82 of the discharge dampers open a predetermined amount, the damper finish swap 163 is closed completing a circuit to the motor beginning relay 165 which begins the blower motor 167 into operation.
The discharge dampers are usually maintained at a place as set by the potentiometer 123. Nevertheless, if desired, distant control switches 157 A and 159 A could also be offered in the potentiometer circuit. The profile dampers are robotically operated by the damper motor 32 and the stress controller 122 to offer the right move in accordance with the stress drop on reverse sides of the burner. In the event either or each of the switches 157 A and 159 B are opened, the current to the potentiometer 123 is various, and the dampers are open to a greater extent rising the move of air from the blowers. These switches are normally closed, but may if desired be open in the occasion either or both of a pair of exhaust followers are turned on to exhaust air from the building.
During winter weather, the change 102 is adjusted in place forming contact between the blower part of the furnace and the heating section thereof. Additionally it is crucial that the blower motor be functioning, as determined by the air circulate swap 182. Current then flows by means of the conductor 202 to the flame safeguard 204 and to the contact 206 via the interior wiring. From the contact or terminal 206, the present flows via conductors 220 and 223 to the pilot valve 222 which opens the stream of gasoline to the pilot valve manifold. This connection extends by the conductor 177, switch contacts 185 and conductor 190. To be able to actuate the burner circuit, it is necessary that the low gas swap 192, the excessive gasoline limit swap 195, and the excessive limit switch 199 be closed. Concurrently current flows by way of the relay change 210 to the ignition transformer 214 which fires the spark plug 219. This circuit remains closed for a predetermined length of time. If the scanner 205 detects flame, a circuit can also be closed from the terminal 203 by means of the interior wiring of the system 204 to the terminal 207. This closes a circuit by means of the conductors 224 and 227 to the principle fuel solenoid 226 which opens this fuel valve and allows gasoline to stream to the excessive strain fuel manifold throughout the burner.
Simultaneously, with the closing of the main gas valve 226, a circuit is closed by means of conductor 229 and relay swap 230 to conductors 231 leading to the relay coil 232, the other terminal 233 of which is related by conductor 234 to line wire G. Energization of the relay coil 232 opens the circuit to the ignition transformer 213, and closes a holding circuit by the relay swap 210 and conductors 231 to the relay coil 232, providing a holding circuit which locks in place. As a consequence of the fact that through the winter weather, the furnace pilot lights remain on constantly the relay 211 is organized for guide reset once the furnace has been turned off. The gas move to the excessive strain manifold of the burner is controlled by modulating motor 241.