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-Temperature measuring probes
Thesystemoperates withoneor twoorthree temperature
measuringprobes.TheBRAHMA contact probes type ST06
we usuallyemployenablegreatmanufacture andservice
advantages andguaranteethesameperformance as
immersion sensors.In caseofshort-circuitor interruptionof
the operation of oneof theprobes, depending onthetypeof
boiler thetemperature adjustmentsystemcan either operate
withthe remainingprobe, signallingafailure, orcancelany
heat demand,preventingthe boiler fromoperating. The
probe fitted to theprimarycircuitalso acts aslimit
thermostat,thusallowingany heat demand to be cancelledif
the water temperatureexceedsthe preset limit temperature.
- Safety thermostat
Ingeneral,theboiler isperfectly safe against possible
overheatingin theprimarycircuitbymeansofasafety
thermostatconnectedontheSMand inseriestothe gas
valvecontrol.The thermostatstops thegas flowand
consequently extinguishes theflame;thenastartingattempt
occurs followedbylockout. Beforetryingtostartanew
ignitioncycle, is necessarya manualreset.
- Limit thermostat
Thisthermostatisreadby themicro andwhenitopenthe
systemstop the gas flowwithconsequentlyextinguishesthe
flameandthe controlboard displaythe errorstate.
- Airpressure switch(forclosed-chamberboilersonly)
It checks thecirculationofcombustionproductsinthe
combustionchamberandallowsboiler ignitiononly ifthe fan
is operating and the draftis regular;it alsoensures the boiler
safetyshutdown ifoneofthese conditionsfails during
operation.Uponrequest, inopen-chamberboilers the air
pressure switchcanbe replacedbyacombustion products
discharge safetydevice usingthesameconnector but
another pin.For the connectionseethe wiringdiagram
section.
- Water pressure switch
It ensures thatthe primarycircuitpressure iswithinthe
requiredoperation range. Incasethe pressure is toolow,the
temperature adjustmentsystemcancelsany heat demand
and the type of failure appearson the powerswitchboard.
- Water pressure trasducer
It ensures areadingoftheprimarycircuitpressure.The
valueof thepressure is displayed inthecontrol board. In
case the pressureistoolow,thetemperature adjustment
systemcancelsany heat demandandthe typeof failure
appearson the power switchboard.
- Water flow switch
TheSMisprearranged foran inputconnectionsignalling
domestic water drawing.Thissignal canbe generated bya
flowsensor (flow switchor flowmeter): in this case the three-
wayvalve(ifavailable) iselectrically controlledbythe
system; otherwisethesignalcanbegeneratedautomatically
byanhydraulicthree-wayvalve.
- Room thermostat
Theroomthermostat(orchronothermostat)isconnected to
theSMby twowires; itisdesignedto operatewithacontact
isolated fromthe powersupply line.
- Timer
TheSM isprovided withaconnectionfor atimer(12-24Vor
220V)mountedon theboard to adjust theheatingtime,as
requiredbythenewstandardsregardingenergy saving.
Thanks tothistimer, theuseof achronothermostatisnot
required.
- Externalprobe
Thesystemisprearrangedforthe connectionto anNTC
sensor (similar to the one usedin temperatureprobes),
whichmeasures theexternaltemperature outside the
buildinginwhichtheinstallationisplaced. Theavailable
adjustmentsinheatingmode are the requiredambient
temperatureandtheheatdispersioncoefficientoftheroom
walls. Thetemperatureappearingonthedisplayis the
primarycircuittemperature, resulting fromthetwopreset
parametersandtheexternaltemperature.Uponvariationin
thelatter one,theprimarycircuittemperature changes
automaticallyto adjustthe ambient temperature according to
the preset value.
- Control board
This mother boardsupply more types ofcontrol boardwith7
segmentdisplayorLDC, withpush-buttonsor regulator
trimmers.
NB: All the customcharacteristics are describe in the customer
use manual.
DIRECTIONSFOR INSTALLATION
• RespecttheapplicablenationalandEuropeanstandards
(e.g. EN60335-1/prEN50165)regardingelectricalsafety.
• Connect live and neutral correctly;the non-observanceof
live-neutral polarity maycause adangeroussituation.
Polaritymust be respected evenin casetheboardisin
non-polarized version.
• Theearthof theboard mustcomingfromthestarearthof
the boiler,notdirectlyfromtheearth-line.Theboard-earth
isnot safetybutonly functional. Theearthsignalmust be
connectedas shown in the figure below
• Beforestartingthe systemcheckthecablescarefully;a
wrong wiring candamage the devices and compromise the
safetyofthe installation.
• Connect anddisconnectthecontrolsystemonlyafter
switching off the powersupply.
• The system canbe mountedin anyposition.
• Avoid exposing the system todripping water.
• Theapplianceinwhichthis temperature adjustment
systemismounted must provideadequateprotection
against therisk ofelectricshock(atleast IP20).
• Avoidplacingcontrolsignalcablescloseto powercables.
Avoid placing ignitioncablesclosetoother cables.
