Potter Electric Signal Company Special Hazards Systems

1. Potter Electric Signal Company Special Hazards Systems We will cover the basic operation of release panels and explain some of the common terminology used. We are going to cover single interlock, double interlock, and deluge systems. Explain how each system works and how they are monitored. We will cover the basic operation of release panels and explain some of the common terminology used. We are going to cover single interlock, double interlock, and deluge systems. Explain how each system works and how they are monitored.

2. A release panel is basically a fire alarm panel with the extra features necessary for the operation of solenoid valves used on pre-action, single interlock, or double interlock systems. In most instances the release panel will not be the main fire panel in the protected premises. The release panel will be monitoring initiating devices that are protecting a particular area of the premises. The release panel�s system alarm, trouble, and supervisory relay contacts will then be monitored by the main fire alarm panel. Per NFPA72, 1996, 3-10.7, The initiating devices for the protected area are supposed to be connected directly to the release panel. The release panel does not monitor the main building fire panel. Both fire alarm and release panels monitor all of the devices and wires connected to them, as well as the AC power, back up batteries and the panel itself. Because of this, the panel has 3 status conditions other than normal condition. A release panel is basically a fire alarm panel with the extra features necessary for the operation of solenoid valves used on pre-action, single interlock, or double interlock systems. In most instances the release panel will not be the main fire panel in the protected premises. The release panel will be monitoring initiating devices that are protecting a particular area of the premises. The release panel�s system alarm, trouble, and supervisory relay contacts will then be monitored by the main fire alarm panel. Per NFPA72, 1996, 3-10.7, The initiating devices for the protected area are supposed to be connected directly to the release panel. The release panel does not monitor the main building fire panel. Both fire alarm and release panels monitor all of the devices and wires connected to them, as well as the AC power, back up batteries and the panel itself. Because of this, the panel has 3 status conditions other than normal condition.

7. This should not be confused with a 4 wire smoke detector which will be explained later. Class A circuits are not used very often. They may be required by FM, an insurance company, or government facility. Requirements for class A wiring should be put in the bid spec�s when the job is let out to bid. They are just a way to try to guarantee that all of the devices on the circuit will work, or at least that they won�t fail because of a broken wire. This should not be confused with a 4 wire smoke detector which will be explained later. Class A circuits are not used very often. They may be required by FM, an insurance company, or government facility. Requirements for class A wiring should be put in the bid spec�s when the job is let out to bid. They are just a way to try to guarantee that all of the devices on the circuit will work, or at least that they won�t fail because of a broken wire.

12. Release systems are basically dry pipe systems that use an electrically operated valve instead of a dry pipe valve. Designed to overcome the operational delay of conventional dry pipe systems. Also eliminate the possibility of accidental water discharge due to damaged pipes or sprinklers The water supply valve is operated independently of the opening of sprinklers. The valve is operated by a compatible releasing panel.Release systems are basically dry pipe systems that use an electrically operated valve instead of a dry pipe valve. Designed to overcome the operational delay of conventional dry pipe systems. Also eliminate the possibility of accidental water discharge due to damaged pipes or sprinklers The water supply valve is operated independently of the opening of sprinklers. The valve is operated by a compatible releasing panel.

13. NOTE: The pre-discharge time is generally an adjustable timer on the release panel. It is primarily used on chemical extinguishing systems. The purpose of the timer is to allow the appropriate personnel time to investigate the situation, or leave the protected area before the agent is released. (Standard on PFC100RC & 2000RC, not available on 4410) NOTE: The pre-discharge time is generally an adjustable timer on the release panel. It is primarily used on chemical extinguishing systems. The purpose of the timer is to allow the appropriate personnel time to investigate the situation, or leave the protected area before the agent is released. (Standard on PFC100RC & 2000RC, not available on 4410)

15. Water flow switches on single or double interlock systems, or deluge systems must be a pressure type device. The switch is installed in line with the intermediate chamber or alarm port. This section of piping may run to a water motor gong or just to a drain. Under normal (no alarm) condition, there is no water or pressure in this section of piping. When water flows into the system, it also flows into this port. The pressure switch will operate to indicate waterflow when the pressure reaches 6 psi. These devices do not need a retard as there should be no water surges. The PS10A would be the waterflow switch for any type of preaction or deluge system. Water flow switches on single or double interlock systems, or deluge systems must be a pressure type device. The switch is installed in line with the intermediate chamber or alarm port. This section of piping may run to a water motor gong or just to a drain. Under normal (no alarm) condition, there is no water or pressure in this section of piping. When water flows into the system, it also flows into this port. The pressure switch will operate to indicate waterflow when the pressure reaches 6 psi. These devices do not need a retard as there should be no water surges. The PS10A would be the waterflow switch for any type of preaction or deluge system.

16. The supervisory air pressure on single and double interlock systems should be monitored. On systems with 5-15 psi, the PS10-1A will provide a low air signal. For systems with 15-175 psi, the PS40-2A will provide a low air signal These devices would be connected to a supervisory zone on the release panel. This is an indication that the system is low on pressure for some reason, possibly just a failed compressor. It would not be an alarm condition & would not trip the solenoid. If a low air switch is being used as part of a double interlock system requiring both a smoke/heat detector and loss of air pressure before the system trips. The low air switch must be connected to an alarm zone. This would create an alarm condition. On systems with 5-15 psi, the PS10-1A will provide a low air signal. For systems with 15-175 psi, the PS40-2A will provide a low air signal A pressure switch with 2 contacts can be connected to both zones to perform both functions. Set 1 contact at a slightly higher pressure and connect that to the supervisory zone. If the problem is just a bad compressor, someone should be able to take action before the low air alarm switch trips and causes a false alarm. The supervisory air pressure on single and double interlock systems should be monitored. On systems with 5-15 psi, the PS10-1A will provide a low air signal. For systems with 15-175 psi, the PS40-2A will provide a low air signal These devices would be connected to a supervisory zone on the release panel. This is an indication that the system is low on pressure for some reason, possibly just a failed compressor. It would not be an alarm condition & would not trip the solenoid. If a low air switch is being used as part of a double interlock system requiring both a smoke/heat detector and loss of air pressure before the system trips. The low air switch must be connected to an alarm zone. This would create an alarm condition. On systems with 5-15 psi, the PS10-1A will provide a low air signal. For systems with 15-175 psi, the PS40-2A will provide a low air signal A pressure switch with 2 contacts can be connected to both zones to perform both functions. Set 1 contact at a slightly higher pressure and connect that to the supervisory zone. If the problem is just a bad compressor, someone should be able to take action before the low air alarm switch trips and causes a false alarm.

17. The release panel must be compatible with any 2 wire smoke detectors that may be connected to it. The panel must also be listed with the solenoids or deluge valve that is connected to it. This information should be in the manual for the panel. Linear Heat Detection (Protectowire) Protectowire wire is a very high resistance cable. 1 ohm per 5 feet. If you are using this you must make sure the panel you are using is capable of operating with that much resistance. For instance, up to 3500� or 700 ohms can be connected to each zone of the Potter PFC4410 for a total of 14000 feet for the panel. The release panel must be compatible with any 2 wire smoke detectors that may be connected to it. The panel must also be listed with the solenoids or deluge valve that is connected to it. This information should be in the manual for the panel. Linear Heat Detection (Protectowire) Protectowire wire is a very high resistance cable. 1 ohm per 5 feet. If you are using this you must make sure the panel you are using is capable of operating with that much resistance. For instance, up to 3500� or 700 ohms can be connected to each zone of the Potter PFC4410 for a total of 14000 feet for the panel.

18. The polarity on indicating circuits and release circuits reverses when that circuit is activated. It is important to note whether the polarity shown on the panel wiring diagram is for a normal or alarm condition. This does vary depending on the manufacturer. The reason they reverse polarity is for supervision. The panel provides voltage on the wires and reads the current draw from the EOLR ( End Of Line Resistor). If voltage is applied to a horn, the horn will sound, so there is a diode built into the horn. This diode blocks the voltage from going into the horn so the horn does not make any noise. The voltage only goes across the resistor. When the circuit activates and polarity reverses, the voltage now goes through the horn & the horn sounds. The polarity on Potter release panels is shown in a normal condition. Note the indicating appliance has the black lead connected to the positive terminal and the red lead connected to the negative terminal. When the circuit is activated the positive terminal becomes negative and visa versa. The same goes for the release circuit except the solenoids do not have a diode built into them. Therefore the Potter panels use an End of Line Diode assembly which is a diode & resistor in parallel with each other. This assembly is wired in series with the solenoid. If you are using a panel that does not have an end of line device for the solenoid, make sure the panel supervises the release circuit for shorts.The polarity on indicating circuits and release circuits reverses when that circuit is activated. It is important to note whether the polarity shown on the panel wiring diagram is for a normal or alarm condition. This does vary depending on the manufacturer. The reason they reverse polarity is for supervision. The panel provides voltage on the wires and reads the current draw from the EOLR ( End Of Line Resistor). If voltage is applied to a horn, the horn will sound, so there is a diode built into the horn. This diode blocks the voltage from going into the horn so the horn does not make any noise. The voltage only goes across the resistor. When the circuit activates and polarity reverses, the voltage now goes through the horn & the horn sounds. The polarity on Potter release panels is shown in a normal condition. Note the indicating appliance has the black lead connected to the positive terminal and the red lead connected to the negative terminal. When the circuit is activated the positive terminal becomes negative and visa versa. The same goes for the release circuit except the solenoids do not have a diode built into them. Therefore the Potter panels use an End of Line Diode assembly which is a diode & resistor in parallel with each other. This assembly is wired in series with the solenoid. If you are using a panel that does not have an end of line device for the solenoid, make sure the panel supervises the release circuit for shorts.

19. Pre-Action Systems Use closed sprinklers attached to a piping system containing supervisory air pressure. The water is held back by an electrically operated valve. The valve is connected to a UL listed and FM approved releasing panel that is compatible with the valve. The releasing panel is monitoring initiating devices such as smoke or heat detectors and pull stations, as well as water flow, valve tamper, and air supervisory switches. The first system we will discuss is the Single Interlock system. Single interlock means only one event, such as a smoke or heat detector operating must occur in order for the panel to open the solenoid.Use closed sprinklers attached to a piping system containing supervisory air pressure. The water is held back by an electrically operated valve. The valve is connected to a UL listed and FM approved releasing panel that is compatible with the valve. The releasing panel is monitoring initiating devices such as smoke or heat detectors and pull stations, as well as water flow, valve tamper, and air supervisory switches. The first system we will discuss is the Single Interlock system. Single interlock means only one event, such as a smoke or heat detector operating must occur in order for the panel to open the solenoid.

20. This is a typical single interlock preaction system. There is a small amount of supervisory air in the system. A low pressure supervisory switch monitors the supervisory air pressure. The smoke or heat detectors are connected to the initiating zone of the release panel. There is also a pull station connected to another zone on the release panel. Activation of either of these zones will activate the release circuit.This is a typical single interlock preaction system. There is a small amount of supervisory air in the system. A low pressure supervisory switch monitors the supervisory air pressure. The smoke or heat detectors are connected to the initiating zone of the release panel. There is also a pull station connected to another zone on the release panel. Activation of either of these zones will activate the release circuit.

21. Here A sprinkler opens, allowing air to escape. Here A sprinkler opens, allowing air to escape.

22. The low air switch [zone 4], detects the drop in pressure. If the air pressure drops due to a compressor failure or damaged pipe. The low air switch will put the release panel in a supervisory condition The valve will remain closed.The low air switch [zone 4], detects the drop in pressure. If the air pressure drops due to a compressor failure or damaged pipe. The low air switch will put the release panel in a supervisory condition The valve will remain closed.

23. The panel could then ring a supervisory bell. The panel could then ring a supervisory bell.

24. Here we are back in a �Normal� condition: A smoke detector [zone 1], or pull station [zone 2], operates.Here we are back in a �Normal� condition: A smoke detector [zone 1], or pull station [zone 2], operates.

25. The panel goes into alarm and energizes the solenoid. The panel goes into alarm and energizes the solenoid.

26. This removes pressure from the diaphragm chamber of the deluge valve. This removes pressure from the diaphragm chamber of the deluge valve.

27. This allows water to flow into the sprinkler piping and the alarm line of the deluge valve. When the pressure in the alarm line reaches 6psi, the water flow switch trips. The panel then rings the water flow bell This allows water to flow into the sprinkler piping and the alarm line of the deluge valve. When the pressure in the alarm line reaches 6psi, the water flow switch trips. The panel then rings the water flow bell

28. Water is now available to flow out of any sprinklers opened due to fire. Water is now available to flow out of any sprinklers opened due to fire.

29. Are designed for applications such as refrigerated areas, or areas requiring maximum protection against inadvertent operation. Two independent events must occur before the system will discharge water. #1. The piping must lose air pressure, caused by a sprinkler opening due to heat from a fire. #2. An initiating device such as a smoke or heat detector, or pull station must be in alarm. Both of these events must occur at the same time in order for the system to flow water Are designed for applications such as refrigerated areas, or areas requiring maximum protection against inadvertent operation. Two independent events must occur before the system will discharge water. #1. The piping must lose air pressure, caused by a sprinkler opening due to heat from a fire. #2. An initiating device such as a smoke or heat detector, or pull station must be in alarm. Both of these events must occur at the same time in order for the system to flow water

30. This is a typical Double Interlock system: The system is cross zoned, this requires both the low air switch and smoke detector to be in alarm at the same time to operate the solenoid. This would be program #7 on the Potter PFC4410 This is a typical Double Interlock system: The system is cross zoned, this requires both the low air switch and smoke detector to be in alarm at the same time to operate the solenoid. This would be program #7 on the Potter PFC4410

31. Here A sprinkler opens allowing air pressure to escape. Here A sprinkler opens allowing air pressure to escape.

32. When the air pressure drops low enough, the low air switch operates. The panel goes into alarm. The solenoid stays closed because only one zone is in alarm. If a low air switch with two contacts is used, one of the switches could be adjusted to trip at a slightly higher pressure. This switch could be wired to the supervisory zone. This would then send a low air supervisory signal if a compressor failed. The situation could be corrected before pressure dropped low enough to cause an alarm. The low air switch causes an alarm condition because it is connected to a zone programmed as a conventional alarm zone. This is because a supervisory condition cannot release the solenoid. When the air pressure drops low enough, the low air switch operates. The panel goes into alarm. The solenoid stays closed because only one zone is in alarm. If a low air switch with two contacts is used, one of the switches could be adjusted to trip at a slightly higher pressure. This switch could be wired to the supervisory zone. This would then send a low air supervisory signal if a compressor failed. The situation could be corrected before pressure dropped low enough to cause an alarm. The low air switch causes an alarm condition because it is connected to a zone programmed as a conventional alarm zone. This is because a supervisory condition cannot release the solenoid.

33. Here we are with the same system back in a �Normal� condition again. Then a smoke detector operates. Here we are with the same system back in a �Normal� condition again. Then a smoke detector operates.

34. The panel goes into alarm. The solenoid stays closed because only one zone is in alarm. The panel goes into alarm. The solenoid stays closed because only one zone is in alarm.

35. Now the fun starts, the small smoldering fire that tripped the smoke detector has now produced enough heat to open a sprinkler. This allows air pressure to escape. The detector is still in alarm. Now the fun starts, the small smoldering fire that tripped the smoke detector has now produced enough heat to open a sprinkler. This allows air pressure to escape. The detector is still in alarm.

36. The low air switch detects the drop in pressure and causes a second alarm on the panel. This completes the cross zoning.The low air switch detects the drop in pressure and causes a second alarm on the panel. This completes the cross zoning.

37. The panel now energizes the solenoid. The panel now energizes the solenoid.

38. The open solenoid removes the pressure from the diaphragm chamber of the deluge valve. The open solenoid removes the pressure from the diaphragm chamber of the deluge valve.

39. Water now flows into the sprinkler piping and the alarm line of the deluge valve. When the pressure in this line reaches 6pis, the water flow switch trips. The panel then rings the water flow bell. Water now flows into the sprinkler piping and the alarm line of the deluge valve. When the pressure in this line reaches 6pis, the water flow switch trips. The panel then rings the water flow bell.

40. Water now flows out of any sprinklers that have been opened by the fire. Water now flows out of any sprinklers that have been opened by the fire.

41. That concludes the single interlock presentation. Now we will start the double interlock system.That concludes the single interlock presentation. Now we will start the double interlock system.