US3310010A - Draft fan control circuit for underfeed stoker fired coal furnaces - Google Patents

Description

1967 w. w. ROBSON, JR 3,310,010

DRAFT FAN CONTROL CIRCUIT FOR UNDERFEED STOKER FIRED COAL FURNACES Filed on. 19, 1964 INVENTOR.

WILLIAM W. ROBSON JR.

United States Patent 3,310,010 DRAFT FAN CONTROL CIRCUIT FOR UNDER- FEED STOKER FIRED COAL FURNACES William W. Robson, Jr., 1621 Highland, Wilmette, Ill. 60091 Filed Oct. 19, 1964, Ser. No. 404,989 7 Claims. (Cl. 110101) This invention relates to an improved draft arrangement and control for solid fuel consuming furnaces and more particularly to automatically timing and varying the furnace draft in relation to the on and off and heat demand cycles of the furnace.

Coal burning furnaces with underfeed stokers are generally equipped with a draft fan that is generally driven by the stoker motor so that the draft is delivered constantly at full capacity simultaneously with the delivery of the fuel to the fire bed.

It is known that the draft supplied to the fire bed for combustion should be enough to support complete combustion yet be kept low enough in velocity to reduce as much as possible the tendency of fine particles of ash and partially consumed coal to be carried over into the boiler or hot air ducts.

Also, since the widespread introduction and enforcement of strict air polution ordinances, the amount of smoke and soot given off by coal fired furances is critical. Such usually occurs immediately after each start-up and shut-down of the stoker.

In automatically controlled coal fired heating units the feed of the fuel is generally controlled by a temperature sensitive switch such as a thermostat. When significant temperatures fall below a required level heat is demanded of the furnace by the thermostat starting the stoker motor and when temperatures have been restored the thermostat stops the stoker. During the interval that the room is above this predetermined temperature the fire bed is generally kept at a very low fire by the natural draft through the dampers and the fire bed burns down, and the longer the intervals between the demands for fuel feed the thinner the fire bed becomes. Consequently, when the stoker feed is started and simultaneously therewith the full draft is also applied, there is little resistance to the draft as it goes through the thin fire bed. The speed of the air of the draft as it passes through the fire bed permits the air to pick up the small particles of fly ash that have not fallen through the fire bed to the ash floor and also allows it to pick up the soot and small coal particles that are introduced with coal and have not had a chance to become fused to the bigger coal. The unrestricted draft blows these particles into the boiler and out the chimney producing a smoke cloud of fly ash and unburned particles of the coal.

Along with producing the cloud of particles, the full draft at start-up blows an excess of relative cool air into the furnace, chilling the fire and also reducing the efiective temperature within the furnace. This heat potential is carried by the draft out the chimney and wasted to the atmosphere. This lowers the efficiency of the furnace and the heat loss has to ultimately be made up by the additional combustion of more coal.

After the fire bed is built back to its working thickness and the fire is at full capacity, the full draft is required as the fire needs the air supplied by the full draft to support it is in complete combustion as mentioned before. This phase continues until the demand control by the thermostat has been satisfied and the fuel feed is turned off.

As the coal feed stoker and fan are driven by the same motor, a turning oil? of the stoker also stops the forced draft fan. The only draft remaining is the natural draft "ice of the furnace. But as the fire bed is still thick with unburned coal at this time, there is a high resistance to the natural draft and it does not supply enough air to support complete combustion. This means that the heat of the burning fire bed on the raw coal that was introduced immediately before the feed was shut off, will heat the coal without burning it, thereby boiling olf the volatile gases and coking the coal. The unburned volatile gases pass to the atmosphere through the chimney and produce a dense smoke.

Again the efiiciency of the furnace is reduced because the burnable volatile gases are allowed to escape to the atmosphere without utilizing their heating ability and smoke ordinances are further violated.

The foregoing problems produced by the full draft running simultaneously with the feed are well known. Most methods attempting to diminish the problem involve various types of numerous controls that adjust the open and closed position of the dampers to regulate the forced draft. But all damper control devices have the disadvantage of employing some mechanical linkage for positioning the dampers, and as the dampers must be positioned somewhat close to the fire bed, they are easily corroded by the surrounding atmosphere making the small adjustments more difficult and harder to control. Also, no manner of control of the opening and closing of the dampers can provide a sufficient amount of draft to support combustion of the unburned coal after the forced draft has been turned off. Therefore the problem of boiling off volatile gases producing smoke cannot be solved by damper controls.

Accordingly, it is an object of this present invention to provide an improved draft control employing draft fans of a predetermined capacity regulated by an electrical timing circuit to provide a light but firm draft when the coal feed starts and until the fire bed attains its working thickness, then provide a full draft for the duration of the fuel feed, and finally to provide another light but positive draft after the feed stops and until the volatile gases in the remaining coal have been ignited.

It is another object of this invention to povide a draft fan control system that will vary the draft to the fire bed and provide the most efficient conditions for combustion and heat transfer at any and all given times with a minimum amount of heat lost through the chimney the overall efficiency 'of the furnace is greatly increased without creating smoke and without coking of the coal.

It is another object of the invention to provide a method of producing a variable draft automatically controlled that will reduce the soot and fly ash entering the boiler or blown up the chimney and also reduce the amount of volatile gases escaping unburned'to the atmosphere, thereby reducing the contamination entering the atmosphere.

It is another object of this invention to provide a draft fan control system which has no movable parts to corrode or become fouled yet will provide a simple, inexpensive, and universal modification of equipment presently in use that will increase their efiiciency and provide a method of reducing their exhaust contamination so they can conform to the stricter contamination ordinances.

It is a still further object of this invention to provide a draft control that has a minimum of moving parts and is completely independent of damper control operation so that the controls can be placed at any convenient location and be free from the highly corrosive atmospheres surrounding a furnace.

These being the objects of the invention, other and further objects will be noted from the description to follow 3 taken in conjunction with the accompanying figures in which:

FIG. 1 is a schematic drawing of the control circuit of the present invention, and

FIG. 2 is a schematic drawing of a modification of the control circuit of FIG. 1.

A draft fan control circuit of the present invention as shown in FIG. 1 can be electrically connected to an underfeed stoker unit conventionally having a forced draft fan that runs when the stoker feed motor is also running. In adapting furnace units presently in use to embody the invention a slight but fixed modification of the present units is made, namely a reduction in the capacity of the draft fan to a fan of approximately 50% capacity, and the provision of an inexpensive second draft fan matching the reciprocal of said approximately 50% capacity. These fans are then controlled as shown in the circuit diagram of FIG. 1. The percentages may :be varied as desired to sharpen the results with equipment of various suppliers.

As shown in FIG. 1, the stoker mechanism 32 and one draft fan 30 may be driven by the same motor 34 as is conventional. The draft fan 30 can either be the original equipment regular large fan but with its output cut down or can be a replacement fan for the regular large fan having the desired fraction of the capacity of the large fan replaced. This means that the modifications required to change equipment presently in operation to the automatic control of the draft fans of the present invention is minimal namely cutting down on a fan already there or replacing it and the addition of a small draft fan with an independent motor drive. Provision of a low draft concurrent with the stoker operation is particularly advantageous where automatically timed intermittent feed is employed for sustaining the fire bed during long off periods.

The operation of this circuit is as follows:

A thermostat or temperature controlled normally open switch has a switch armature 11 which is closed when the controlling temperature drops below a predetermined minimum. This allows current to pass it and through the coil 12 of an electromagnetic relay switch Y, energizing the coil 12 and thereby closing the switch arm 13 against contact Y Closed switch Y contact passes current from the power line 42 through contact Y and into line 38 from which it flows through the drive motor 34 for both the stoker 32 and the cut down draft fan 30. This starts both the coal feed and the cut down draft and provides the fire bed with a small initial start-up draft that will not be strong enough to blow the soot and fly ash out the chimney but will provide sufiicient air for complete combustion.

The current in line 38 also goes to a time switch 16, such as a Tork Time Switch, model Number 1163l2M 8001, through line 43. The current in line 43 flows through a time controlled switch arm 46 disposed at rest on contact CR of line 48 and from there through the clock element 18 of the time switch 16. As long as the switch arm 46 is resting on contact CR the clock is energized and also current can flow to the coil 24 of another electromagnetic relay switch X energizing the coil 24 thereof. Therewith the normally closed switch arm 26 is opened from contact with X and does not allow any current to reach the motor of the second fan 28. Accordingly at demand start-up the only forced draft supplied to the fire is from the 50% capacity draft fan 30.

As the demand switch 10 remains closed the time switch 16 receives current through contact CR until the cam 20 driven by the clock motor 18 rotates sufficiently to force the switch arm 46 from contact CR to engagement with the contact Cw. The contact Cw is not yet supplied with current so the switch arm 46 does not receive any current and the time switch 16 stops. As no current is flowing through the switch arm 4-6, the current to the relay switch X is also cut off, de-energizing the coil 24 thereof, allowing the switch arm 26 of the relay switch X to close on the contact X to pass current from the line 38 through the switch arm 26 and into the motor of the second draft fan 28. With both fans running, a full draft is supplied to the fire bed.

The time switch 16 can be adjusted to provide a predetermined time lapse between closure of the demand switch 10 and the opening of the switch arm 46 of the time switch 16 from engagement with contact CR and making engagement with the contact CW. This provides time for the incoming coal particles to ignite or fuse to larger particles; for the fly ash to be shaken to the ash fioor by the motion of the incoming coal; and, for the fire bed to recover its working depth. Both fans are then placed in operation to provide the full capacity dnaft necessary to support the combustion of coal being fed to the fire box as long as the demand switch is closed regardless of the length of time this occurs.

As soon as the heat demand is satisfied, the switch 11 is opened by the thermostat control, thereby stopping the current flow through the coil 12 to de-energize the electromagnetic relay switch Y. The switch arm 13 of the relay Y breaks away from Y and returns to its normal position against contact Y and line 38 does not receive any more current and therefore the motor drive 34 of the stoker 32 and the draft fan 30 does not receive any current and both stop running. Engagement with contact Y by the switch arm 46 of the time switch 16 simultaneously supplies current through lines 40 and 54 to contact Cw and the clock element 18 and cam 20 of the time switch 16 are again activated. Also, current again flows to the coil 24 of the electromagnetic relay switch X, energizing the coil 24 and opening the switch arm 26 of the X relay and closing the switch arm 25 on the contact X of the X relay. This allows the current in the line 40 to flow through the X relay switch at X and into the second draft fan 28 so that a small draft is provided to support combustion of volatile gases emitted from the fresh coal that had entered the fire bed just prior to the feed being turned off.

Again the clock element 18 of the time switch 16 is set for a predetermined lapse of time for burning the escaping volatile gases before the cam 20 has turned sufficiently to allow the switch arm 46 of the time switch 16 to open at the contact Cw and close at the contact CR. The time lapse can be manually adjusted so that the switching occurs at the average time it requires for the volatile gases of the fresh coal to have been burned. After the switch arm 46 of the time switch snaps back to the contact OR the clock element 18 is stopped and the coil 24 of the electromagnetic relay switch X is deenergized as the contact CR is connected to an open line 38. When the coil 24 of the X relay is de-energized the switch arm 25 opens from the contact X and stops the draft fan 28. Thus, at this point no f-uel feed or forced draft is supplied to the fire bed and it is allowed to burn at its low rate as supported by the natural drafts until the thermostatic demand switch 10 again is closed and the cycle explained is repeated.

FIG. 2 refers to a circuit diagram basically the same as that shown in FIG. 1 except the position of the draft fan contacts within the X relay switch have been changed to provide more versitility for the circuit with two motor fans separate from the stoker motor. As will be seen by following this circuit, one fan can be used to provide a forced draft during the initial feed period; the full combustion period; and, during a short period of time after the feed has stopped so that a fan of any desired percentage of a theoretical full draf-t down to the minimum draft can be employed with the remaining fan running only during the full combustion period to bring the draft capacity up to the full capacity draft during the full combustion period.

The circuit as shown in FIG. 2 first with the manual switch 36 closed operates in the following manner:

As previously explained, closing the temperature controlled demand switch starts the cycle by energizingthe Y relay switch and in this circuit, the stoker motor 34 is connected directly to the demand switch 10 and begins the feed of coal with the closing of the demand switch 10. Closing the contact switch arm 13 on the contact Y; of the Y relay allows current to flow through the line 38 and with the manual switch 36 closed, the small capacity draft fan 30 also starts simultaneously with the feed. At this time, as explained in FIG. 1, the coil 24 of the X relay is also energized, opening the switch arm 26 and the contact X of the X relay. This status continues and the draft fan 28 is the only draft fan operating until the cam of the time switch 16 snaps the switch arm 46 of the time switch 16 from the contact CR to contact Cw. When the switch arm 46 of the time switch 16 is cammed to engage the contact Cw the X relay is deenergized and the switch arm 26 of the X relay closes on the contact X and current will fiow to the second draft fan 28. Current is still flowing through the manual switch to the draft fan 30 so that during this period both fans 28 and 30 are running to provide in combination a full draft to the fire bed.

Camming the switch arm 46 of the time switch 16 from the contact CR to the contact Cw shuts off the current to the clock elements 18 stopping it so that the cam 20 holds the switch arm 46 of the time switch 16 on the contact Cw. Therefore the full draft and fuel feed as just explained continues until the heat demand is satisfied and the switch arm 11 of the switch 10 opens to deenergize the coil 12 of the Y relay switch and also stop the flow of current to the stoker motor 34 whereby fuel feed is stopped. The switch arm 13 of the Y relay returns to its normal position on the contact Y thereby stopping the current in the line 38; in turn stopping the draft fan 28; and directing the current flow through the line 40. With the current flowing through line 40 and the switch arm 46 of the time switch 16 on the contact Cw as explained above; the time switch 16 again starts to run; the coil 24 of the X relay is again energized; and the switch arm closes on the contact X of the X relay allowing the current in line 40 to go to the draft fan 30, making it continue to run.

The draft fan and the clock 18 of the time switch 16 continue to run a pre-determined length of time controlled by the cam 20 of the time switch 16. When the cam 20 has rotated sufficiently to allow the switch arm 46 of the time switch 16 to snap back to the contact CR the current to the time switch 16 and current to the coil 24 of the X relay is stopped, de-energizing the coil 24. Thus, the switch arm 25 of the X relay is opened from the contact X and the draft fan 30 stops. At the end of this period the circuit is at its initial position, ready for a repeat of the cycle when further demand is made by the thermostat 10.

Using the circuit of FIG. 2 with the manual switch 36 closed as explained above permits the use of one draft fan 30 to provide the initial draft at the beginning of the fuel feed; a part of the full draft during full combustion; and the partial draft continuing for a short period after the fuel feed has stopped.

Employing the same circuit of FIG. 2 and opening the manual switch 36 changes this relation only in that the draft fan 30 will not run during the full combustion period. The draft fan 30 will run during the period of initial fuel feed by the current flowing through the switch arm 26 closed on the contact X of the X relay, and

during the period after the fuel feed has stopped receiving current through the switch arm 25 closed on the contact X of the X relay. The contacts X and X of the X relay are both open during the period of full combustion with current flowing through the contact X running only the draft fan 28 during this period. Thus the draft fan 28 can be a full draft fan allowing the original full size draft fan of the furnace to be employed at full capacity, with the secondary draft fan 30 being of any desired optimum capacity to provide a forced draft only on start-up of the fire during the initial feed and also during a short period after the fuel feed has stopped.

It is seen that by employing either of the above circuits of FIG. 1 or FIG. 2 a draft fan arrangement and control is provided, that can be incorporated with existing coal burning furnaces fed with underfeed stokers, utilizing the present equipment of the system making the modifications with some additional minor equipment, thereby simple and relatively cheap.

It is also seen that the draft fan control and arrangement just described provides an automatic regulation of the forced draft delivered to a solid fuel consuming furnace that will supply the varying draft requirement necessary to support complete combustion of the fuel without supplying an excessive forced draft that would tend to blow small particles of ash and soot out the chimney. Thus by eliminating the discharge of the fine particles of fly ash and soot to the atmosphere and at all times providing a sufficient quantity of air to support complete combustion, thereby reducing the discharge of unburned volatile gases to the atmosphere, the furnace units can operate within the rigid requirements of the anti-air polution ordinances. Also, the induction of air by a forced draft that is just sufiicient to support complete combustion eliminates an excessive cooling of the fire bed and furnace that occurs when such is supplied with a larger draft than required. Thus the described draft fan control and arrangement will also increase the overall efficiency of a furnace unit employing it.

Having thus described the invention and the desirable characteristics and advantages thereof, it will be apparent to those skilled in the art that various and further changes can be made within the stated objects without departing from the spirit of the invention, the scope of which is commensurate with the appended claims.

What is claimed is:

1. A draft control circuit for a Stoker-fed coal-fired furnace having a stoker, a plurality of fractional blowers compositely supplying a full forced draft to said furnace,

thermostat means having a two position heat demand which means including connections arranged to activate the stoker and one of the blowers in its heat demand position, timer means having a two position switch controlled thereby including connections to the heat demand switch means arranged to activate the timer means for a predetermined period of time in one of. its positions at the start of said heat demand position and for a subsequent predetermined period of time when the thermostat means and said heat demand switch means resume their other position, and

relay means including connections to the timer means arranged for energization and deenergization concurrently with activation of said timer means and including two switches and connection therefrom to the blowers arranged to activate said blowers independently,

said heat demand switch in its said other position and said timer means switch in the other one of its positions energizing said relay means to close one of its switches to activate the other of said blowers in series with said heat demand switch and timer means switch in their said other positions whereby a partial draft is supplied whenever the timer'means is energized.

2. A draft control circuit for a stoker-fed coal-fired furnace having a stoker, a plurality of fractional blowers compositely supplying a full forced draft to said furnace,

a heat demand means including a relay having a switch closed when energized and a connection therefrom to said stoker and one of said draft 'blowers,

timer means connected to said closed switch for activation thereby and including a switch closed after a predetermined running time of the timer means,

means interconnecting said closed switches and the other one of said blowers in series to activate the latter whereby a fractional draft is supplied to the furnace during the activation of the timer means of the second switch is connected to the open position of the third switch to deactivate the timer, said 8 third switch being opened at the end of a predetermined prior of time in the timer cycle, and the other two switch positions of the first and second switch means being connected together, and

and a full forced draft is supplied to the furnace a second relay connected to said third switch and enerthereafter during head demand. gized concurrently with said timer means and includ- 3. Aforced draft control for use with acoal-fired stokering a two position fourth switch means energizing fed furnace having a stoker, said other blower whereby a full draft is supplied a plurality of fractional draft blowers for compositely whenever the first means is closed upon heat desupplying a full forced draft to said furnace, 10 mand and the timer is deactivated, said predetermined a heat demand switch means, period of time being set by manual adjustment of a timer means having connections to and controlled by said timer.

said switch means and including a switch having two 6. A draft control for a stoker-fed coal-fired furnace positions, having a plurality of fractional blowers compositely supsaid switch means activating said timer means through 10 plying a full forced draft to said furnace,

said timer switch in either position and said timer a stoker, switch deactivating said timer means when moved by heat demand means having a two position switch inthe timer means to its opposite position, eluding connections with said stoker and blowers conductor means interconn cting Said Switch, Switch arranged to activate the stoker and both of the blowers means and blowers and arranged to control said while in its heat demand position, blowers selectively, timer means having a two position switch and includsaid timer switch activating one of said blowers and said i connections between said switches arranged to Stoker Whil th ti r m s is activated With its activate the timer means and deactivate one of said switch in one position in series with the switch means blowers for a predetermined period of time when said in its heat demand position, timer switch is in one position at the start of said heat said switch means and said timer switch actuating both d d means, d thereupon reverse the position f Said l w rs and id t r While the timer is of said timer switch to deactivate the timer means deactivated y its Switch being movfid to its other and activate said deactivated blower, said heat deposition with the switch means in heat demand posid means reversing the position of its switch at tion, and the end of the heat demand prior to deactivate said Said time]? Switch in Said other POSiTiOIl energizing Said stoker and blowers, and said timer .means connections timer means and ne of aid w s a when to said heat demand switch being arranged to actihe wi ch m n i deenergized whereby a partial vate said timer means with both said switches in draft is pp when the timer is energized and their other positions and activate one of said blowers another Partial draft is pp for a Short Period 30 for a predetermined time whereby a partial draft is aft r t h t demand has C as supplied whenever the timer means is energized In a draft Control for hard 'fuel burning furnaces 7. In combination with an electrically powered coalhaving a motor driven underfeed stoker, the combination fi d fu h i a t k of a plurality of fractional capacity blowers compositely two blowers for supplying compositely the forced draft 40 supplying a f ll f d d afit to said furnace,

1equifed for furnace With each pp y a a plurality of motor means, one of which simultaneoustion thereof, ly operates said stoker and one of said blowers and means for energizing said stoker motor including a two another one f hi h Operates th the blower,

position temperature controlled heat demand switch, a timer including Switch means having alternate Posia timer energized by said demand switch and having ti alternately Closed Switches one Of which is Closed a first relay including switch means having alternate when the demand switch is in its alternate position, i i Connection means arranged energizing one of Said a second relay including switch means, having alterblowers in series with said heat demand switch when Hate positions, in heat demand Position, means interconnecting said switch means in one of connection means for energizing the other of said their respective positions d to a Source f l t i blowers including a relay Controlled through the power and arranged to energize the second relay, said other of said timer switches and having a switch closed timer and both f i motor means h id fi t when energized, said relay being connected in series relay is energized, With the timer Switches, and Said relay Switch being means interconnecting said switch means in their alterconnected in series with the stoker, with one of the nate positions being connected together d t id blowers and with the heat demand position of the source of Electric power and arranged to energize demand Switchsaid other motor means when said first relay is de- 5. In a circuit 'for controlling a plurality of draft energizfid and said SeCOnd relay i energized, blowers each providing a fraction of the full forced draft thermostat means including a i h d a connection and a stoker motor for a solid fuel burning furnace the arranged to energize said fi t relay during h 1 Combination of mand upon the furnace, and

a temperature controlled means having a first switch said time1- moving its i h means f it on osimeans Closed upon heat demand: tion to its other position to deenergize itself and said a first relay connected to and energized by said first sficond flay il id fi t relay is deenergized by switch when closed and having a two position second Said thermostat switch means with one position connected to the stoker and to one blower when the relay is energized, Retferemes Cited by the E i a timer means operating a two positign tjhitrd switch UNKTED STATES PATENTS means and including connections t ere e ween arranged to activate the timer means in both positions 2,132,980 10/ 1938 Woolley et a1. 103-13Z in combination with connections between the first 2,158,673 5/1939 Carter et a1. 11 and second switch means in which said one position 2,497,879 2/ 1950 Frerer ll0-72 KENNETH W. SPRAGUE, Primary Examiner.

Claims (1)

1. A DRAFT CONTROL CIRCUIT FOR A STOKER-FED COAL-FIRED FURNACE HAVING A STOKER, A PLURALITY OF FRACTIONAL BLOWERS COMPOSITELY SUPPLYING A FULL FORCED DRAFT TO SAID FURNACE, THERMOSTAT MEANS HAVING A TWO POSITION HEAT DEMAND WHICH MEANS INCLUDING CONNECTIONS ARRANGED TO ACTIVATE THE STOKER AND ONE OF THE BLOWERS IN ITS HEAT DEMAND POSITION, TIMER MEANS HAVING A TWO POSITION SWITCH CONTROLLED THEREBY INCLUDING CONNECTIONS TO THE HEAT DEMAND SWITCH MEANS ARRANGED TO ACTIVATE THE TIMER MEANS FOR A PREDETERMINED PERIOD OF TIME IN ONE OF ITS POSITIONS AT THE START OF SAID HEAT DEMAND POSITION AND FOR A SUBSEQUENT PREDETERMINED PERIOD OF TIME WHEN THE THERMOSTAT MEANS AND SAID HEAT DEMAND SWITCH MEANS RESUME THEIR OTHER POSITION, AND RELAY MEANS INCLUDING CONNECTIONS TO THE TIMER MEANS ARRANGED FOR ENERGIZATION AND DEENERGIZATION CONCURRENTLY WITH ACTIVATION OF SAID TIMER MEANS AND INCLUDING TWO SWITCHES AND CONNECTIONS THEREFROM TO THE BLOWERS ARRANGED TO ACTIVATE SAID BLOWERS INDEPENDENTLY, SAID HEAT DEMAND SWITCH IN ITS SAID OTHER POSITION AND SAID TIMER MEANS SWITCH IN THE OTHER ONE OF ITS POSITIONS ENERGIZING SAID RELAY MEANS TO CLOSE ONE OF ITS SWITCHES TO ACTIVATE THE OTHER OF SAID BLOWERS IN SERIES WITH SAID HEAT DEMAND SWITCH AND TIMER MEANS SWITCH IN THEIR SAID OTHER POSITIONS WHEREBY A PARTIAL DRAFT IS SUPPLIED WHENEVER THE TIMER MEANS IS ENERGIZED.

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