The EVLA Correlator fire detection and suppression system consists of three subsystems:

• Fike FM-200 Fire Suppression System. FM-200 was introduced in 1993 as a replacement for Halon and has gained acceptance as the world's leading clean gaseous fire extinguishing agent. FM-200 extinguishes fire via a combination of chemical based fire inhibition and cooling. It is environmentally acceptable, safe to use with sensitive equipment, fast acting, efficient and effective. Several smoke detectors in both the ceiling and the floor are a part of the FM-200 system. Two tanks contain the FM-200 gas; one large located outside of the correlator room that dumps into the room and one smaller tank, located in the room, that dumps into the floor space.
• Fenwal AnaLASER II High Sensitivity Smoke Detector consists of a laser particle counter detector head and a high efficiency fan module connected to a piping network that spreads throughout the ceiling of the correlator room. It provides early warning smoke detection.
• Tyco DV-5 Red-E Cabinet Integrated Deluge Fire Protection Package is a pre-assembled fire protection valve package that provides water, via a sprinkler system, as a last resort if fire presists after the FM-200 dump.

In addition, the two CPCC computers are wired into the Fike FM-200 panel to monitor status of the smoke detectors and, in the event of fire, power down the correlator in a timely manner to minimize damage from fire suppressents.

What Happens When There is a Fire?

See also: FM200 Alarm Sequence and Shunting Meeting7-27-06.df.pdf
There are three stages of fire/smoke detection. In the event of fire, the event stages will happen in this order:

1. Supervisory is caused by the AnaLASER High Sensitivity Smoke Detector. It is said that this is sensitive enough to be set off by a soldering iron. The Supervisory alarm is also activated from loss of pressure in the deluge valve system, loss of pressure in the FM-200 tanks, [tbd - find ALL the supervisory alarm triggers]. The operators will see the alarm on their alarm box and the CPCC's will inticate the alarm on the operator's GUI in the control room but will take no further action.
2. First Smoke Detection is when the first Fike smoke detectors activates. The following actions take place:
   • 'ALARM' lamp illuminates on control panel face,
   • An alarm bell and visual indicator are energized
   • Auxillary functions are activated as follows:
     • Operate door holder/closures on access doors
     • Shutdown HVAC equipment
     • Release vent magnetic holders and actuate underfloor fire damper
     • Send the signal to the CPCC computers (which only indicate the alarm on the Operator's GUI but take no further action)
3. Second Smoke Detection is when the second and subsequent Fike smoke detectors activate. Active automatic fire suppression starts as follows:
   • Illuminaate 'PRE-DISCHARGE' on control panel face
   • Energize a pre-discharge horn/strobe device
   • Send signal to enable preaction (sprinkler) system
   • Close dampers
   • Start 60-second shunt trip timer
   • Send signal to CPCC's which will commence powering off the 320 correlator boards. This is done in a staged manner to minimize current spikes and takes approximately 50-seconds to complete.
   • Upon completion of 60-second timer:
     • Shunt trip is activated removing all power to the room
     • FM-200 gas is dumped into the room and into the floor space below
     • "SYSTEM FIRED" lamp is illuminated on control panel face
     • Outside Discharge Strobe is enabled
     • Building fire alarm activated
     • Fuseable links melt closing fire dampers
   • If the fire is still burning hot enough, it will open a sprinkler head causing a pressure drop in the sprinkler system piping. The FM-200 is wired into the sprinkler system to provide an enabling signal when its detectors activate. If both the enabling signal is present and a pressure drop happens, the sprinklers will activate.

Cheetah Xi Control Panel

The heart of the Fike FM-200 Fire Suppression System is the Cheetah Xi Contol Panel. All physical devices that are a part of the fire detection and suppression system are connected to the control panel including the Fenwal AnaLASER, the Tyco sprinklers, the room's HVAC units and CPCC systems. Some devices, such as the smoke detectors, are input devices and others, such as HVAC power control and CPCCs are outputs. The major devices that are connected to the control and that make up the overall system will be discussed individully.
The control panel is discussed in detail in the Product Manual

The following matrix correlates to the inputs and outputs of the control panel:

The control panel for the EVLA Correlator is located outside of the correlator room near the right-side (facing the correlator room from the Operator's area).

The components of the system, such as the emergency manual discharge switches, sprinkler system, FM-200 gas tanks and smoke detectors are all wired into the control panel. The control panel and the rest of the system is backed up by a 24-volt battery so it will operate independently of AC power.
In this early photograph the CPCC system has not yet been wired into the contol panel; it will be shown below in the CPCC section.

Extinguishing System Release and Abort Buttons

There are two sets of Manual Release and Abort switches:

• Near the emergency exit door at the rear of the room on Northeast wall,
• On the outside of the room under the main control panel near the main entrance on the Northwest wall.

The Red Manual Release Button causes an immediate FM200 Discharge and Shunt Trip activation. This button should only be activated if fire or smoke is present while an employee is also present and feels it should be used. Otherwise, the smoke detectors will discharge the FM200 once two detectors are activated and the 60-second time delay expires. In other words, the manual dump should only be activated under extreme circumstances; the system was designed to automatically release the fire suppressant at the appropriate time.

The Yellow Abort Button resets the 60-second timer back to 60 seconds and holds it from further countdown while the button is held pressed. When released the 60-second count resumes. The countdown can be permanently aborted by pressing the 'Reset' button on the Fike Control Panel:

If two people are in the room and wish to abort the extingquishing agent release and electrical shunt trip, one can hold a yellow 'Abort' button while the other goes to the Fike Control Panel to press the 'Reset' button. If only one person is present, they can press and release the yellow Abort button to give them a full 60-seconds to run to the Fike Control Panel and press the 'Reset' button.

Emergency Stop Buttons

The three Emergency Stop Buttons are located on the inside of the correlator room near each of the three doors. These switches will immediately activate the Shunt Trip Mechanism in the main AC power mains breaker box. This will cut all power to the room. 48V power from the power plant will be disconnected thus shutting down all the correlator racks and boards. A/C power to the room will be removed turning off the remaining equipment in the room like the servers, CBE, HVAC units, overhead lights, etc. The room will go dark except for a battery operated emegency light on the front entrance wall.

The Emergency Stop Switches, when activated, will not cause suppressent release or vent closure. The Fire Suppression system will remain functional.

The following is a short 9-second video showing the Shunt Trip in action (note: the video is ineffective without audio - please contact kryan if audio does not work in your browser):

If the correlator is operating at normal load this sudden loss at such high current levels is not good for the equipment. Because of this, the shunt trip should not purposely be activated without the correlator being powered down before hand.

For a longer video showing resetting of the breakers afterwards

Also for testing purposes the Shunt Trip Mechanism can be bypassed as described next.

Shunt Trip Bypass Switch

The Shunt Trip Mechanism can be bypassed for testing purposes. When in the 'Test' position the shunt trip will not be activated by any means. Also, when the shunt trip is bypassed ('Test' position), it will NOT prevent suppressent release in the event of fire or manual release button activation.

A new bypass switch was installed June 17, 2020 and tested in both positions with each of the three Emergency Stop Switches and with the 2nd smoke detector activation 60-second timer expiration.

FM-200 Fire Suppressent

The EVLA Correlator's Fike fire suppression system uses HFC-227ea, called Heptafluoropropane, as the first line of fire suppression. HFC-227ea, named 'FM-200' by Dupont falls in the category of 'Clean Agents' by the NFPA-2001 - Standard for Clean Agent Fire Extinguishing Systems and is an acceptable replacement for Halon. The term 'Clean Agent' is defined by NFPA-2001 as: Electrically nonconductive, volatile, or gaseous fire extinguishant that does not leave a residue upon evaporation.

From www.fireengineering.com: [FM-200] is a colorless, liquefied gas that is rapidly fully discharged (within 10 seconds) through nozzles into an area as a clear, nonconductive vapor in fixed total flooding applications. Relatively low concentrations of this agent (between 4 and 9 percent) are required in total flooding systems. FM-200® extinguishes fire by removing heat and inhibiting the chemical chain reaction (fire tetrahedron) inside the flame zone. It is a clean agent that has acceptable toxicity for use in occupied spaces and is effective on Class A, Class B, and Class C fires.

FM-200 is safe for humans; in fact, it is also used as the propellent in some asthma inhalers.

FM-200 Safety Data Sheet Version 2.2

Other Components of Fike System

The miscellaneous other components that make up the Fike Fire Detection and Suppression system are depictied here.

There are 9 ceiling smoke detectors and 9 subfloor detectors. Every other one is tested every 6 months with artificial smoke; so, all 18 get tested once per year.

Monitor and control modules are 'addressable devices' that are used to monitor or control 'dumb' components of the system such as the flashing strobe, alarm bell, siren, FM-200 release valves, etc. They hava an infrared window that allows remote control and monitor from a handheld remote control unit.

The bell and the horn/strobe devices and their control modules are shown here. They are located near the main door on the inside of the correlator room. The control modules are labeled with their addresses: '09' is the top one that controls the bell and '10' controls the horn/strobe.

Detector and Display/Control Panel

The AnaLASER II High Sensitivity Smoke Detector used in the WIDAR correlator room consists of a detector and display/control panel (shown above) and a piping network (described below). The unit installed in the correlator room is the higher of two available sensitivity ranges and is referred to as the "Ultra AnaLASER II Detector". It is capable of detecting particles of combustion at levels of obscuration as low as 0.00015%/ft. This is sensitive enough to detect invisible products of combustion such as the outgassing of plasticizers from overheating PVC wire insulation and electrical components, or small changes in the ambient level of obscuration during the incipient stage of a fire. A room that is filled with smoke so that no light may be seen is said to have an obscuration level of 100%/ft.

Inside the box is a high-efficiency centrifigual fan that draws air continuously from the ceiling of the correlator into a piping network and through a detector head. The detector uses a laser to count the number of discrete particles of a specific size in a given time period.

From Fenwal AnaLASER Description:

The Detector’s particle size discrimination feature allows only a specific range of particle sizes (between 0.01 and 10 microns) to be measured and counted as products of combustion. Anything above or below this range is generally ignored and does not contribute to smoke signal calculations. This discrimination band corresponds to the center of the range of all particles of combustion. Dust particles, which are typically larger than 10 microns, are ignored.

When a combustible material reaches it’s ignition temperature, the combustion becomes self-sustaining and is called a fire. At temperatures much below the ignition temperature, chemical reactions generate airborne particles. This is typically called the incipient stage of a fire and is followed by visible smoke, flame and finally an intense heat stage. Detection during the incipient stage allows time for corrective action, possibly preventing an escalation of the fire condition, and thus minimizing fire damage.

Piping

The Fenwal AnaLASER II system uses a network of 3/4" PVC sampling pipe that is run throughout the ceiling of the correlator room. The pipe is sealed at all joints and has end caps attached at the end of each run. Sampling ports (holes) are drilled in diameters and at intervals determined by a software program for the specific dimensions and characteristics of the room.

The requirements for the correlator room sampling piping are:

• Air sampling network piping and fittings shall be airtight and permanently fixed.
• Sampling System piping shall be conspicously identified as "Smoke Detector Samping Tube. Do Not Disturb." as follows:
  • At changes in direction or branches of piping;
  • At each side of penetrations of walls, floors, or similar barriers;
  • At intervals on piping sufficient to provide read visibility within the space, but no greater than 20ft.

The approximate layout of the sampling pipe is shown in the schematic diagram at the top of this page.

Tyco DV-5 Preaction Valve

The Tyco Model DV-5 Deluge Valve resides in the bottom half of the Tyco Red-E Cabinet located just outside the correlator room near the large FM-200 Gas Tank. The deluge system is integrated into the Fike FM200 system and is activated electrically when a second smoke detector activates (as opposed to mechanically from the loss of pressure that occurs when a sprinkler head opens).

The DV-5 is a diaphragm style valve that depends on water pressure in the diaphragm chamber to hold the diaphragm closed against the water supply pressure. A solenoid valve can be activated to release the diaphragm pressure thus allowing supply water into the system. When the Fike Fire Detection system detects a second alarm from its smoke detectors it sends an enabling signal to the deluge system's control box which, in turn, opens the solenoid valve to allow water to flood the sprinkler system pipes.

A more complete description of the valve can be found here: Tyco DV-5 deluge valve

An excellent YouTube video of how it works is can be found here: TYCO DV-5 Electric Actuation

Potter PFC-4410 Contol Box

The Potter PFC-4410 is integrated into the Tyco Red-E Cabinet and is connected to the Fike FM200 Cheetah control box. When a second smoke detector activiates, the signal from the Fike system is sent here and enables the deluge system. This does not mean that the sprinklers will be activated, it only means that the system will be enabled so that if the heat from a fire is hot enough to activate a sprinkler head, it will have water to it.

A more complete description of the control box can be found here: Potter PFC-4410 Control Box

The full manual for the control box: PFC4410 Intstallation, Operation and Instruction Manual

Tyco Red-E Cabinet

The TYCO DV-5 Red-E Cabinet is a pre-assembled fire protection valve package enclosed within a free-standing cabinet. The entire package is pre-wired and pre-plumbed. The valve package includes the system (manual) shut-off control valve, automatic water control valve, and water-flow/supervisory switches.

A more complete description of the cabinet can be found here: Red-E cabinet

Physical Description

The CPCCs are a pair of SuperLogics SL-4U-SBC-CL-865G-BA. cpcc1 is powered from the correlator room -48VDC battery through an inverter while cpcc2 is powered from the buildings AC power mains.

The CPCCs connect directly to the Rack Power Module Interface Boards (RPMIBs) in each of the 16 correlator racks via 100-pin SCSI cables and are also directly hardwired into the room's fire detection and suppression system. In this manner the room could lose all network communications and the CPCCs will still be able to monitor the fire detection system and power down the correlator if necssary.

Three relays (in the alarm box outside the Southwest door), one for each level of smoke detection, are wired to the RPMIB in Rack S002 (the three red/black wires in the gray sleeve). Though deceiving In this picture, the single red line is connected to pin 6U-9. This is the TTL pullup line for the three monitor points at SPR0, SPR1 and SPR2 (the 3 lines with the 220-ohm resistors) for smoke alarm stages 1, 2 and 3 respectively..

The Supervisory and 1st Zone alarms come from the horizontal terminal block (called P2) term pins 6 and 3 respectively and go to the SPR0 and SPR1 pins respectively on the monitor input terminal block on the Rack S002 RPMIB. The 2nd Zone alarm is from the installed optional CRM-4 Relay Module (the verticle terminal module) term pin 3 and goes to the monitor input terminal block pin SPR2 on the RPMIB.

Functional Description

Two CPCCs run in parallel as peers; at least one must be running at all times or the correlator will power off. CPCCs are wired into the fire detection and suppression system and will power down the correlator boards to protect them in the case of sprinkler discharge; they monitor board temperatures and regulate rack fans accordingly; they provide the mechanism for powering up and down the system, in a staged manner, to prevent large current surges.

The CPCCs run independently and both function as 'masters' (i.e. there is no master/slave). CPCCs constantly talk to each other over what has been called the 'MirrorLink'. They independently monitor the system and then compare results via the MirrorLink. If one CPCC should fail the other one resumes as normal without having to come out of a standby mode. If both CPCCs fail to where the board power-on signals go off, all correlator boards will be powered off. This was designed as a fail-safe mode.

The CPCCs are wired into the fire detection/suppression system's main control panel which sends relay closure signals to the CPCCs for each of the three alarm stages. In addition to the appropriate LED lighting on the Operator's GUI Smoke Alarm Panel, a message will be displayed in the message box area of the GUI: *** Stage X Smoke Detection *** where 'X' is '1', '2' or '3'. This is followed by a status message indicating that no automatic CPCC action will take place for stage 1 and 2 alarms and what action the CPCCs will take if it is a Stage 3. The Stage 3 action depends on the setting of property called cpcc.initiating.system.shutdown.on.stage3.smoke as follows:

• cpcc1 : if cpcc1 detects stage 3 it initiates shutdown on both itself and cpcc2 (via the MirrorLink). If cpcc2 alone detects stage 3, nothing happens.
• cpcc2 : if cpcc2 detects stage 3 it initiates shutdown on both itself and cpcc1 (via the MirrorLink). If cpcc1 alone detects stage 3, nothing happens.
• neither : nothing happens
• either : if either cpcc detects stage 3 it initiates shutdown and commands the other to do likewise via the Mirrorlink.
• both : the cpcc that detects stage 3 initiates shutdwon on itself only. If both detect stage 3, the system will shutdown; if only one detects stage 3, the system will remain up (it takes both cpcc's to shutdown the system).

For smoke alarm testing BOTH CPCCs must have their cpcc.initiating.system.shutdown.on.stage3.smoke property set to neither to avoid shutting down the correlator during testing. When testing is complete, the value must be set back to either

The procedure for setting this property to disable/enable automatic shutdown is under the control of the VLA Operators.