Patent Document

This invention relates to a periodic tester to determine readiness of fire pump system and more particularly to a periodic tester to determine readiness of fire pump system which facilitates monitoring of a fire pump system without the need for human intervention. 
     BACKGROUND OF THE INVENTION 
     The need for immediate usability of a fire pump system at the time of a fire is obvious. Periodic testing to insure this is essential but unfortunately not always applied. Moreover, the present monitoring systems require human intervention. This is a two-part problem in that first, the human has to be skilled in monitoring the system for it to be effective, and secondly, the human has to be consistent in periodically monitoring the system. A system which is less dependent on human intervention will be a desirable invention. 
     Also, the failure of the fire pump controller to start the fire pump motor when needed is most likely due to the failure of two key components. The components that are most likely to cause the failure are the contactor coil and the power on/off pressure switch. A system which monitors these two key components will be a useful invention. 
     Finally, replacing existing systems to incorporate system which monitors these key components without human intervention is expensive. A system which has these capabilities, yet can be retrofitted to existing systems will be a useful invention. 
     SUMMARY OF THE INVENTION 
     Among the many objectives of the present invention is the provision of a periodic tester to determine readiness of a fire pump system which can detect contactor coil failure. 
     Another objective of the present invention is the provision of a periodic tester to determine readiness of a fire pump system which can be conveniently housed in an enclosure mounted adjacent to the fire pump controller. 
     Also, an objective of the present invention is the provision of a periodic tester to detect readiness of a fire pump system which has an audible indication of the failure of the electric motor to start automatically until the alarm is stopped manually. 
     Moreover, an objective of the present invention is the provision of a periodic tester to determine readiness of a fire pump system which either does not disable a normally functioning fire pump system or causes continuous fire pump operation if the periodic tester malfunctions, when interwired per National Electrical Code. 
     A still further objective of the present invention is the provision of a periodic tester to determine readiness of a fire pump system whose period cycle time is adjustable to one week or less. 
     Yet another objective of the present invention is the provision of a periodic tester to determine readiness of a fire pump system which does not require human intervention to operate. 
     Also, another objective of the present invention is the provision of a periodic tester to determine readiness of a fire pump system which can be retrofitted to existing fire pump systems. 
     These and other objectives of the invention (which other objectives become clear by consideration of the specification, claims and drawings as a whole) are met by providing a retrofitted periodic tester for a fire pump which monitors both the contactor coil and the power on/off pressure switch, without the need for human intervention, and sounds an alarm when failure occurs. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  depicts a block diagram of the prior art. 
         FIG. 2   a  depicts a block diagram of the prior art monitored by the periodic tester  100  of this invention. 
         FIG. 2   b  depicts a block diagram of the prior art, without solenoid valve  148 , monitored by the periodic tester  100  of this invention. 
         FIG. 3  depicts a schematic view of the periodic tester  100  of this invention. 
         FIG. 4  depicts a mechanical diagram of the content of cabinet  106  of this invention. 
         FIG. 5  depicts a mechanical diagram of the content of door  108  of this invention. 
         FIG. 6   a  depicts an electrical wiring diagram of the terminal connections of the periodic tester  100  of this invention. 
         FIG. 6   b  depicts an electrical wiring diagram, without solenoid valve  148 , of the terminal connections of the periodic tester  100  of this invention. 
         FIG. 7  depicts a front perspective view of the cabinet  106  with the door in open position  192  detailing the components of the periodic tester  100  of this invention. 
         FIG. 8  depicts a front perspective view of the cabinet  106  with the door  108  in closed position  194  featuring warning lights  180  and  182 , reset button  184 , lock  190 , and audible sound alarm  186 . 
     
    
    
     Throughout the figures of the drawings, where the same part appears in more than one figure of the drawings, the same number is applied thereto. 
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Until recently, there was no requirement for automatic periodic starting of an electric motor driven fire pump, and reliance on the performing of periodic testing were governed by human interest, supported by requirements not rigidly enforced, or even monitored. Since that time, however, all new fire pump controllers are equipped to meet the automatic periodic starting requirement of simulated output system pressure decrease to the normal starting pressure, followed by an immediate alarm indication if the fire pump controller fails to start the motor. 
     This invention identifies each of the two components of the fire pump controller most likely to have failed prior to an automatic periodic start attempt. This identification by nontechnical personnel makes correction of the failure much more timely, hence, reducing the out of service time of the fire pump system. 
     This invention makes the periodic testing less dependent on human capability. Further, it identifies the two leading causes of failure of the fire pump controller to start the fire pump motor when needed, the contactor coil and the power on/off pressure switch. 
     The distinguishing feature of this invention is the improved data presentation of the fire pump controller component or components failure which enables faster correction of the failed condition. Furthermore, this data presentation makes it possible for operating personnel having limited electrical knowledge to provide considerable information to a follow-up technical repair technician. 
     This invention is intended to periodically monitor the readiness of the fire pump controller to start the motor when needed. It is not intended to monitor other deficiencies which may exist in the fire pump system such as closed system discharge valve, open-circuited motor, broken motor-pump coupling and other potential problems. It does not monitor fire pump controller control and alarm components not associated with the starting equipment. 
     Now referring to  FIG. 1 , the typical electric fire pump system  104  of the prior art can be seen. Electrical power input  118  is delivered to the circuit breaker  114  and then delivered to contactor (sometimes referred to as “contactor assembly”)  116 . The contactor  116  is a contactor switch  230  having an electrically operating closing contactor coil  200 , which when activated by power on/off pressure switch  120  will allow electrical power to flow to the electric motor  122  when there is a pressure decrease in sprinkler system  136 . Between electric motor  122  and fire pump  132  is a coupling  130  which connects the two in a working relationship. The mechanical output power of the electric motor  122  is delivered to the fire pump  132  where it is converted to hydraulic power in the fire pump  132  and becomes usable power when there is water flow in the sprinkler or standpipe piping system  136 . 
     Either the sprinkler or standpipe piping system  136  is normally a static hydraulic system, but becomes dynamic when activated directly or indirectly by heat or smoke, usually during a fire scenario. Automatic starting because of a fire is accomplished by sensing the pressure on the sprinkler system  136  at the pump discharge check valve  134 . The resulting rate of water flow is dependent upon the number of sprinkler heads or standpipe hoses  136  opened; thereby determining the hydraulic power delivered to extinguish the fire. 
     Now referring to  FIG. 2   a , the monitoring of the typical electrical fire pump system  104  by the periodic tester  100  can be seen. Electrical power input  118  is delivered to the circuit breaker  114  and then delivered to contactor  116 . The contactor  116  is a contactor switch  230  having an electrically operating closing contactor coil  200 , which when activated by power on/off pressure switch  120  will allow electrical power to flow to the electric motor  122  when there is a pressure decrease in sprinkler system  136 . 
     Automatic starting because of a fire is accomplished by sensing the pressure on the sprinkler system  136  at the pump discharge check valve  134 . The pressure is transmitted by the pilot piping  156  to a power on/off pressure switch  120 . The pilot piping  156  contains two orifice unions  154  which minimize pressure surges to the power on/off pressure switch  120 . 
     Fire pump  132  is preferably a centrifugal pump with output characteristics of decreasing pressure with increasing flow. Fire pump  132  is connected to the public water supply or any suitable supply of water in great enough amounts to properly extinguish a fire. 
     Periodic tester  100  can monitor different versions of the existing systems including those with a solenoid valve  148  and those without. Some versions of pilot piping  156  have a solenoid valve  148  to discharge water to waste  150  at the end of the pilot piping  156 . A periodic time clock  140  activates solenoid valve  148  whereupon there is a fairly rapid drop in pressure at the power on/off pressure switch  120  due to the limited water flow through the orifice unions  154 . When the pressure at the power on/off pressure switch  120  falls to the start setting of the power on/off pressure switch  120  as a result of either a fire or an automatic periodic command to start, the electric motor  122  starts. Electric motor  122  starts when the power on/off pressure switch  120  activates the contactor  116  via the contactor coil  200  to supply electric power to the electric motor  122  to start. Between electric motor  122  and fire pump  132  is a coupling  130  which connects the two in a working relationship. 
     Now adding  FIG. 3 ,  FIG. 4 ,  FIG. 5 ,  FIG. 6   a , and  FIG. 6   b  to the consideration, periodic time clock  140  is programmed for repetitive ON/OFF operation with the ON time being much shorter than the OFF time. One complete cycle is usually one week, but can be set for a lesser time if premise protection from fire damage is paramount. 
     There is only one attempt to start on each ON-OFF cycle, whether successful or not. Upon periodic time clock  140  closing its contacts, it energizes time delay relay  170  as well as the third control relay  178  (sometimes referred to as “CR3”). The contact of the periodic time clock does not directly close the contactor  116  to start the fire pump  132  but applies power to solenoid valve  148  causing it to open and start water flow in the water to waste  150  which decreases pressure to the power on/off pressure switch  120  in the fire pump controller  110 . Fire pump controller  110  is contained in a housing. 
     If the power on/off pressure switch  120  is functioning properly, then prior to the completion of the timing period set on time delay relay  170 , the power on/off pressure switch contacts  120  will close and cause voltage to be applied to the contactor coil  200  which, if not open or short circuited will energize the contactor  116  to deliver power  118  to start electric motor  122 . Lastly, under this normal operating mode, at a slightly later time when time delay relay  170  time period expires, third control relay  178  will dropout, the solenoid valve  148  will close again, and pressure in the pressure sensing line  102  up to the solenoid valve  148  will rise to the pump discharge pressure. The fire pump controller  110  will remain energized until both the running period timer in the controller  110  and the pressure on the power on/off pressure switch  120  exceeds its stop setting. Time delay relay  170  does not reset itself until periodic time clock  140  transfers to the OFF period, thereby providing the single start attempt during each ON-OFF cycle. 
     Third control relay  178  has a normally open contact which closes immediately with the transfer of periodic time clock  140  from OFF to ON. This closure energizes alarm time delay relay  172  (sometimes referred to as “TDR 1”) through the instantaneously closed time delay relay  170  contacts which remains closed and continue to time out until first control relay  174  (sometimes referred to as “CR1”) energizes. First control relay  174  is connected across two of the three output power terminals of the contactor  116 . The setting of the time delay period of the time delay relay  170  must be greater than the normal interval of time between closure of the power on/off pressure switch contacts and the closure of the contactor  116  in fire pump controller  110  to prevent the conclusion of the single start attempt before the contactor  116  normally closes. 
     Now, the malfunction of fire pump controller  110  is added to the consideration and illustrated. As mentioned earlier, the time opening contact of time delay relay  170  must be greater than the time closing contact of alarm time delay relay  172 . The third control relay  178  drops out as time delay relay  170  times out which causes alarm time delay relay  172  to dropout if it is still energized. 
     If in the normally operating sequence, if no water discharges to waste  150  when solenoid valve  148  is opened, a malfunction is present. The malfunction is likely the result of a plugged or otherwise distorted pressure sensing line  102 . 
     If, however water discharges to waste and the pump does not start, then the power on/off pressure switch  120  is most likely unresponsive, improperly set, or otherwise defective, causing the malfunction. Or, the malfunction may be a failed contactor coil  200 . The malfunction may be a combination of more than one of the above, or not related to any of the above. At this point, a further analysis of the system is necessary. 
     In the event of this malfunction, alarm time delay relay  172  will time out because first control relay  174  did not pick up which energized first alarm relay  160  (sometimes referred to as “AR1”) which results in the illumination of failure to start light  180  and the sounding of audible alarm  186 . Audible alarm  186  is silenced and failure to start light  180  is extinguished by pressing alarm reset switch  184 . At this point, the periodic tester  100  will remain in the quiescent state until the next operation of the periodic time clock  140 . 
     Adding to the consideration, another scenario is when the periodic tester activates a malfunctioning system. In this scenario, the sequence follows the normal sequence and solenoid valve  148  opens and water flows to waste  150 . However, fire pump controller  110  does not start fire pump  132 . Alarm time delay relay  172  times out, causing the first alarm relay  160  to pick up and the failure to start light  180  is illuminated, and audible alarm  186  sounds, But, in addition, second control relay  176  (sometimes referred to as “CR2”) which is connected across contactor coil  200 , is energized which indicates there is voltage present across an open circuited contactor coil  200 . If a short circuited contactor coil  200  occurs, it will burn to an open circuited coil rapidly as there is no overload current protection in the contactor coil circuit  200 . 
     When second control relay  176  is energized, its normally open contact closes which illuminates the coil failure alarm light  182 . In actuality, both failure to start light  180  and coil failure alarm light  182  will illuminate almost simultaneously. 
     When the second control relay  176  is energized but the first control relay  174  has not picked up because of contactor coil  200  failure, the contact of the second control relay  176  will cause the second alarm relay  162  (sometimes referred to as “AR2”) to pick up and the coil failure alarm light  182  is illuminated. 
     Now adding  FIG. 4  to the consideration, the contents of cabinet  106 , housing periodic tester  100 , can be clearly seen. First control relay  174 , second control relay  176 , and third control relay  178  are present and interconnected to terminal block  142 . First alarm relay  160  and second alarm relay  162  are present and connected to terminal block  142  and second control relay  176  and third control relay  178 . Time delay relay  170  and alarm time delay relay  172  are present and connected to terminal block  142  and first control relay  174 , third control relay  178 , first alarm relay  160 , and second alarm relay  162 . Also, the periodic time clock  140  is present and connected to the terminal block  142 , third control relay  178 , time delay relay  170 , first alarm relay  160 , second alarm relay  162 , alarm time delay relay  172 . 
     Now adding  FIG. 2   b  and  FIG. 6   b  to the consideration, in an alternate embodiment, periodic tester  100  can be retrofitted to an existing system which lacks a solenoid valve  148 . In this embodiment the periodic tester  100  connects directly to the power on/off pressure switch  120 . Periodic tester  100  functions the same as described with a few minor variations, mainly in the initial phases. Periodic tester  100  directly activates the power on/off pressure switch  120  and simulates a water pressure drop. The periodic tester  100  connects to power on/off pressure switch  120  through connections with terminal block  142  and more specifically with direct connections to terminals  12  and  13 . The periodic tester  100  jumper starts the power on/off pressure switch  120 . A relay switch may be used to jumper start the power on/off pressure switch  120  or any other suitable mechanism to provide the desired connection. In this embodiment, the output from the third control relay  178  is used to jumper start the power on/off pressure switch  120 . 
     Referring specifically to  FIG. 5  to the consideration, the contents of door  108 , of cabinet  106  which houses periodic tester  100 , can be clearly be seen. Door  108  has a series of name plates  210  which indicate which light or signal is represented at each place. Door  108  has failure to start light  180 . If the fire pump  132  fails to start during a testing cycle, then failure to start light  180  is activated to indicate the failure. This allows personnel to contact appropriate service technicians to remedy the problem. 
     Also, door  108  has coil failure alarm light  182 . If contactor coil  200  is responsible for the failure of fire pump  132  during testing operations, this light is activated. This allows personnel to contact appropriate service technicians to remedy the problem. 
     Finally, door  108  has reset button  184 . If the fire pump  132  fails to start during a routine testing operation, audible alarm  186  will sound. Personnel can press reset button  184  to shut off audible alarm  186 . An optional embodiment is counter  202  which counts the number of times reset button  184  has been successively reset before appropriate service technicians repair the problem. Counter  202  can be reset once the problem has been addressed by an appropriate repair technician. Counter  202  can be electrical, mechanical, or any other suitable mechanism. Counter  202  can be on the exterior or interior of cabinet  106 . 
     Now adding  FIG. 7  to the consideration, the components of cabinet  106  can be clearly seen. Cabinet  106  is depicted with door  108  in the open position  192 . On the interior of cabinet  106  is the periodic time clock  140 . Also, cabinet  106  had lock  190  to prevent unauthorized access to the interior components. 
     Terminal block  142  has wiring attaching to failure to start light  180 , coil failure alarm light  182 , reset button  184 , and audible alarm  186 . Also, first control relay  174 , second control relay  176 , third control relay  178  are present and interact with coil failure alarm light  182 . Moreover, first alarm relay  160  and second alarm relay  162  are present and interact with audible alarm  186 . Finally, time delay relay  170  and alarm time delay relay  172  time out. 
     Now adding  FIG. 8  to the consideration, the cabinet  106  has door  108  in closed position  194 . The exterior surface of door  108  has failure to start light  180 , coil failure alarm light  182 , reset button  184 , and the audible alarm  186 . These emergency warning features are on the exterior of door  108  so any passerby can view the activated light and take appropriate action. Also, door  108  has lock  190  which prevents unauthorized people from accessing the interior components of cabinet  106 . 
     This application—taken as a whole with the abstract, specification, claims, and drawings—provides sufficient information for a person having ordinary skill in the art to practice the invention disclosed and claimed herein. Any measures necessary to practice this invention are well within the skill of a person having ordinary skill in this art after that person has made a careful study of this disclosure. 
     Because of this disclosure and solely because of this disclosure, modification of this tool can become clear to a person having ordinary skill in this particular art. Such modifications are clearly covered by this disclosure.

Technology Category: a