9022_ev395_inst_en_0512

1EDS - TECHNICAL INFORMATION

SPARK DETECTOREV 395

TECHNICAL INFORMATION

EDS srl - Via Ca' Nova Zampieri 6 - 37057 S. G. Lupatoto - VERONA - ITALY - Tel. +39-045-547529 - Fax +39-045-8750065email: [email protected] - Web: www.eds.eu


EV 395 SPARKDETECTOR

The EV395 Spark Detector is suitable for a really quickdetection of sparks that can be conducted in the pipes ofsilos or storehouses that contain flammable materials likewood sawdust, ecc.The extreme quickness of the response of this detectorcan prevent the starting of a fire causing great damages tothings and people.

1 - MOUNTING INSTRUCTIONS

1.1 - The detector can be used as a standalone detector(reccomended) or with its EV521 control unit designedspecifically for this usage. The EV521 can control twoEV395 detectors. This Contro Unit is equipped with astabilized power supply, Test circuits, timers and 4output relays. Moreover the Control Unit contains veryquick circuits so that the response time results very short.

1.2 - Drill a hole of 60 mm of diameter on the surfaceof the pipe to be controlled

1.3 - Install the detector on the external part of the pipeusing the black O ring and the 2 fixing brackets includedor the 4 fixing hole present on the box of the detector

1.4 - Adjust the distance from the surface, using suitablethick materials, so that the internal view window of thedetector is not sticking out too much inside the pipebecause this could be on obstacle for the materialsflowing in the pipe or start an encrustation that couldcause the obscuration of the window.

1.5 - Connect the detector as indicated in the electricdiagram of fig. 1 or, if connected to EV521 ControlUnit, as indicated in the connection diagram detailed inEV521 instructions.

1.6 - As power supply an alternate voltage of 24 Vaccould be used or a 22-28 Vdc direct current which isour suggestion. In this case the power supply terminalson the board do not have polarity.

1.7 - It is possible to connect a TEST button to the 4-5terminals (with normally open NO contact) that permits

to do a periodic operational test of the detector. When thebutton is pressed the detector is tested with a simulationof a detecting a spark getting in its field of view, andconsequently gets in alarm condition driving its output relay

1.8 - The detector has two internal regulations (fig. 2) sensitivity regulation (trimmer P1) regulation of the output relay activation time (trimmer

P2)

These adjustments have to be done according to theenvironment where the detector is installed.

1.9 - The detector has a flied of view of 90 (solid angle)and it's useful for pipes with diameters up to 50 cm. If thediameter is more than that, or if the pipe has an square,rectangular section, etc., it is suggested to use a couple ofEV395 detectors installed on opposite sides watching eachother, to avoid blind zones outside the viewing field of thedetector and to be sure that detection is performed.

1.10 - The output relay can be coveniently used toactivate an electrovalve driving a sprinkler spayingnozzle to perform the automatic extinguishing of thespark in the pipe. So this noozle will spray water for atime duration set by the trimmer P2 (adjustable from 0to 10 seconds). The normal suggested time is 3 seconds.

1.11 - When beign certain of the automatic sparkextinguishing is necessary or in important installations,where security should be set at the highest level, we suggestto install another detector (or detectors couple) at a suitabledistance from the detector or couple of detectors already


2 - OPERATION

2.1 - With reference to fig. 5 about a 2 detectors installation,if a burning spark passes through the first detector's field ofview, the EV395 detector gets in alarm condition, its outputrelay immediately activates and remains activated for a timeduration equal to the one set with P2 trimmer between 0 and10 seconds. The output contact of this relay will be used todrive VL1 electrovalve that will activate the water sprayingby the SS1 noozle for a first extinguishing attempt.

2.2 - If the spark has been extinguished, the system returns tonormal operation, otherwise the spark, continuing its ride, wilenter in the field of view of the second EV395 detector.This will activate its output relay. The contact of this relay willdrive VL2 electrovalve that will activate the water sprayingby the SS2 noozle for a second extinguishing attempt.

installed, for a forward confirmation of the performedextinguishing. If extinguishing was performed correctly this seconddetector will stay inactive, otherwise it will activate and its outputrelay will be used to : activate a second sprinkler spraying nozzle for a second

extinguishing attempt close the output mounth of the pipe by means of an

automatic shutter before the materials are deployed inthe silo

activate a suitable acoustic alarm

3 - RESPONSE TIME

3.1 - The times to evalauate during the designing process of aspark detection system are the following:

T1 - response time of EV395 detectorT2 - response time of the detector's output relayT3 - acquisition time of EV521 Control Unit and response

time of its relayT4 - response time of extinguishing electrovalve VLT5 - filling time of the part of pipe goig from the

electrovalve to the noozle SS and time of water conegeneration

If in the system there's no EV521 Control Unit includedthe time relative to the Control Unit (T3) shall not becounted.The usual values of this times are:

T1 - 3-10 msT2 - 12/15 msT3 - 15 msT4 - 10 msT5 - depends on pipe lenght, pipe section and most of all

on water pressure

3.2 - For designing calculations the T1-T4 time can beconsidered of 60 ms max.The T5 time should be added to that. This time is dependenton the pipe sectionand lenght, on water presssure and onthe used noozle. With a SP34F22 noozle and a waterpressure of 3-4 bar a water speed of 4-6 m/s is obtained.So if the piece of pipe between electrovalve and noozleis 1 m long, the transit time is around 0.2 s.Therefore summing the T1-T5 times the result is 0,26 s.This is the system response time.

4 - NOZZLE POSITIONING

4.1 - The spaying noozle has the function of extinguishingthe spark.Its position must be calculated taking in account thetimes detailed in the previous chapter and the speed ofthe fluid or materials flowing in the pipe.For a calculation of the mean value, a simple Physicsformula can be used:

S = vt

where :S= covered lenght in metersv= speed of the fluid in the pipe m/st= response time of the security system

The fluid speed has to be measured in place.Normally the following speed is measured:

wood industry : 20-30 m/s textile industry : 10-20 m/s

For other applications a measurement is required.So the calculation is simple knowing the 3 parametersof the formula.


4.2 - Example:

fluid speed : 25 m/sresponse time : 0,25 s

calculation :S= 25 * 0,25 = 6,25 m (lenght of spark's run)

So in this case the spraying nozzle has to be positionedat least 6,25 m (7-8 m) far from the point where theSpark Detector is installed, so that the spark can beextinguished by the sprinkler nozzle.A diagram detailing the fluid speed in relation todistance is provided in fig. 1 for the system designers.

As T5 time has a great influence over the total time ,it is necessary to do the following in order todecrease the response time of the system: higher water pressure (4-6 bar) larger pipe section a nozzle with an higher (32-63 l/min)We suggest to use an autoclave of 20-30 litri withpressured tank and pump.If the pipe is long, we suggest to use of a tank with fly-wheel function and unidiectional valve, to avoid theloss of pressure caused by the load loss.

5 - MAINTENANCE

5.1 - The Spark Detector must be periodically cleaned.The detector has to be unmounted from its brackets orfixing and its viewing window has to be washed with acloth dampened with water and little soap. No type ofalchool or solvent should be used.. This operation hasto be done periodically according to the type of fluid.The fluid flowing in the pipe normally keeps thewindow clean by rubbing. The normal dust quantity thatsettles on the viewing window do not have any influenceon the detector's operation because the infrared radiationpasses through the dust.

5.2 - Periodically check the mechanical parts of thesystem.If an automatic shutter or a fluid deviation device isused, it is necessary to periodically verify itsoperation and to lubrificate the moving parts.

5.3 - Periodically verify the operation and tightness ofthe water interception electrovalve. A tightening defectcan cause a flooding of the pipe resulting in damages.

It's good to install up stream a suitable tap and a filter toretain impurities that can have influence on the electrovalveoperation. Another good thing to do is to install some waterdraining elements along the pipe.

5.4 - If the system is installed outside the factory buildingthe freezing cold problem shall be evaluated.The water pipe must be caulked and the elements of theextinguishing system (electrovalve, pressure gauge) mustobe isoleted from freezing.If this precautions are not enough we suggest to use anheating cable commanded by a thermostat so that a tempe-rature of more than 0 degrees.

5.5 - If the systems remains unused for a long time it'sgood to drain all the water from the pipe.

5.6 - Check electrical connections (terminal boards,connectors, ecc.) of the various elements of the system.In particular verify the grounding of the metal elements ofthe system.

6 - OPERATIONAL TEST

6.1 - A TEST button connected to the 4-5 terminals on theboard must be pressed to perform the operational test ofthe Spark Detector. If the installed system includes ControlUnit EV521 the TEST button, positioned on the front panelof the unit or you can press the remote button connected onterminals 17-18 of the Control Unit, if present.


0

5

10

15

20

25

30

0 5 10 15 20 25 30

velocitdel fluido

[m/s]

distanza[m]

tempo di rispostadel sistema 0,25s

non usare

zona consigliata

fig.1

7 - TECHNICAL DATA

power supply : 24 V ac-cc power consumption : 20 mA - 50 mA (alarm) internal voltage stabilizer circuit for protection against ESD viewing angle : 90 response time : 3-15 ms max viewing distance : about 50 cm (Spark dimention

1 mm circa T=800C) alarm led sensitivity regulation : half trimmer alarm duration adjustment : 0 - 10 sec operation with normally activated or deactivated relay output relay : 6A/24 V

box : light alloy fusion protection index : IP 67 dimentions : 140x135x85 weight : 0,7 Kg.

distance

System responsetime 0.25 sec

Suggested area

do not usefluid speed


Fig. 1

Electrical Connections Diagram

NC NA

C

TEST 24Vcc,ca

1 2 4 5 6 73

RELE'EV395

fig.2

ELECTRICAL CONNECTION DESCRIPTION

Relay

INTERNAL ELEMENTS DESCRIPTION

P1=Sensitivity regulation trimmerP2=Alarm duration regulation trimmerJP1=Relay activated/deactivated selection jumperPosition A: relay with memory (remains in alarm until power supply is removed)Position B: relay normally activated mode (alarm duration regulated by P2)Position C: relay normally deactivated mode (alarm duration regulated by P2)L1=alarm led

To verify the circuit operation is sufficient to short circuit the TEST A and TEST B terminals

RELAY


Fig. 4 - Example of system with 2 EV395

Fig. 3 -Example of a system with one EV 395

Pipe Water feed pipe

Spraying NozzleEV395 Spark Detector

electrovalvepressure gauge pressure gauge

electrovalve

nozzle nozzlewater supply pipewater supply pipe

EV395 Detector EV395 Detector automatic shutter

Silo


EV 395 SPARK DETECTORMECHANIC MOUNTING

fig.5

RIVELATORE EV395

staffa

parete della tubazione

viewing window

56.0

162.0

5.0

DS5

81A

EV395 - SPARK DETECTOR

finestra di visione

pipe surface

bracket


EV 395 SPARK DETECTORDIMENTIONS

fig.6

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EDS - TECHNICAL INFORMATION

TECHNICAL INFORMATION

Spark DetectorEV 395

The EDS EV395 Spark Detector is an electronic device suitedto detect sparks in combustible materials transport pipes andchannels, headed to a storing silo.

During the transporting phase, a spark, produced in the previousmanifacturing stages, can be transported mixed with the materials.

If this spark is not detected and neutralized very quickly, once itarrives inside the silo, it can cause a fire or an explosion.So the precise and quick detection of the spark, can be used toprevent great damages and dangers to both people and things andconsequently to elevate the security level of the installation.

The EV395 detector is able to reveal sparks that cross its viewingrange even if they have a great velocity (up to 100 km/h).

The detector is equipped with an optical head sensible to infraredradiation, that has a viewing range of more than 90 degrees (solidangle) and a suitable electronic circuit that provides theamplification and managing of the signal.

When the EV395 detector intercepts a spark it provides thepowering of a relay suitable to switch on optical and acousticalarms. Moreover a fire extinguishing system ( splinker ) can beactivated.For the former function it is suggested to use our EV 521 controlunit that has a great using flexibility.

If the pipes have a large diameter (over 0,5 m.) several EV395detectors can be used to obtain a better security level .If a water spraying automatic extinguishing system is alsopresent,the spark extinguishing can be verified.

ADVANTAGES

signalling quickness and precision remote functioning test available solid metal box easy installation easy maintenance

APPLICATIONS

wood industry:sawdustshavings

textile industry:cottonall other fibres

food industry:cereals

If the transporting pipe has not a cylindric shape, for example squaredor rectangular, it can be necessary to use two opposed detectors, toavoid dead zones external to the viewing range of the detector.

The detector's box is made of fusion light alloy with IP67 protection,and so the internal electronics are protected from dust, shocks andfrom ambient conditions, that can be also corrosive, permitting touse the detector outdoor for a long time without any problem.

The maintenance of this detector is very simple and not frequentlyrequired.

TECHNICAL DATA power supply: 24 V cc or ac power consumption: 20 mA (no alarm) - 50 mA (alarm) optical viewing solid angle: 90 degrees max detecting distance: about 50 cm sensitivity regulation regulation of relay powering time: 1-10 sec pins to connect a remote test button alarm LED output relay: 6A/24V fusion light alloy metal box protection index: P67 dimentions: 140x135x85 weight: 0,7 Kg

11

EDS - TECHNICAL INFORMATION

water feedpipe

electrovalve

pressure meter

EV395 spark detector

transportingpipe

nozzle

water cone

Installation example with two EV395

Installation example with one EV395

shutterSILO

9022_ev395_inst_en_0512

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