BRAHMA 384 User manual

6609_r01 1/8
DIGITAL TEMPERATURE
ADJUSTMENT SYSTEMS
TYPE384
CONTROL BOARDFORAUTOMATIC-
IGNITION ATMOSPHERICBOILERS,
WITH INBUILT E.M.C. FILTER AND
REMOTE IGNITION DEVICE.
DESCRIPTION
Theseelectronicsystemsare suitableforoperating cycleand
temperature controlin closed-chamberandopen-chamber
atmospheric gas boilers.
GENERAL FEATURES
This controlboard is providedwiththe following features:
− single electrode or doubleelectrodeignitionand flame
monitoring (ionization) systemwithremote ignitiondevice;
− possibilityof multipleignitionattempts;
− controlof theboiler parts (systemcirculator,modulating
gasvalve, deflectionvalve, flow switch/flowmeter, air
pressureswitch, thermostats, etc.);
− controls,adjusters and signalsonacustomizedmodule
connected tothe mother boardbymeans ofa flat cable;
− electricalreset (withlockoutstatusstoragein the
EEPROM) or manualreset;
− use of NTCcontact and/or immersionprobes for
temperature measurement (upto 4probes);
− microcontroller-based controloftemperature adjustment
and ignitionand flamemonitoring functions;
− SELV (SafetyExtraLow Voltage) insulation;
− flamemodulationbymeansof aproportional,integraland
derivative (PID)electronic system;
− differentiatedsettingof therequired water temperaturefor
heating and domestic hot water operation mode;
− adjustable boiler max.heat capacityin heating mode;
− domesticmode prioritybymeansofaflowmeter/flow
switch;
− pumpoverrun and lockoutpreventionanddeflection valve
lockout prevention;
− post-purgefunction;
− temperature safetylimitin the boiler primaryhydraulic
circuit;
− prearranged forconnectionto electromechanicallimitand
safetythermostats;
− prearranged foruseinfloor heating systems;
− diagnosticfunctions: heatdemandsignal,boiler lockout,
probescut-off, lackof water inthesystem, lackof stack
draft;
− EMC systemapprovedaccording to the standardEN298;
− prearranged forburnerheat capacitymodulationthrough
gassolenoid valvemodulation;
− prearranged forpumpspeedmodulationaccordingto the
system characteristics;
− varistor protectingfromvoltage transients whichmaybe
generatedin the mainssupply;
− outgoingwater temperatureadjustmentprogramby means
of an outsideprobe;
− operationindependentfromlive-neutralconnectionand
suitable for live-live systems;
− RS232 andRS485interface.
− Opentherm protocolcompatible.
− possible cascadeconnection.

2/8 6609_r01
TECHNICALDATA
Supply voltage: 220/240Vac-50/60Hz
Operating temperature range: -10°C +60°C
Humidity: 95% max.at 40°C
Protectiondegree: IP00
Fuse current: 2A – quick acting
Consumption (withoutloads): 10W
Dimensions: 140mm X100mm
(h45mm)
CONSTRUCTION
The system consists ofthe following operating units:
1. MotherBoard(SM),includingpower supply anda
microcontroller for temperature adjustmentandignition
and flame monitoring functions;
2. RelayModule(MR),onwhichtherelaysof theboard are
mounted;
3. ExpansionBoard (SE – optional) enablingthe
expansionoftheboard withtheadditionofconnections
type RS232,RS485,Opentherm, etc.(this moduleisnot
describedin this data sheet;forinformationpleaserefer to
the relevantproduct documentation).
Thesystemisequipped witha ControlPanel(TC),which is
connectedtothe MotherBoard(SM)bymeansofaflatcable
andrepresents the user'sinterface (push-buttons,
potentiometers, LEDs, 7-segment display,LCD).
Thissystemcan be fittedto a remote ignitiondevice type TR2.
ACCESSORIES
Thesystemcanbe suppliedcomplete withBrahmacontact
temperatureprobes type ST03, ST04, ST07,orimmersion
temperatureprobes type ST06,ST6B,ST09andST11.
For adescriptionabouttemperature probes,please see the
relevantdatasheets.
INTEGRATEDTEMPERATUREADJUSTMENTSYSTEM
Themainfunctions of theboard are mentioned below.
Gasvalvemodulator current control:
NaturalGasRange Current: 20..130mA
LPGRange Current(*): 25..170mA
(*)withJ12closed
Type oflockout
Volatilelockout (Standard)orNon-volatilelockout.
Times (*):
Prepurge time (TP) 0 - 120s
Safety time (TS) 3 - 120s
Spark ignitiontime (TSP) TS –1
Drop-out timeonflamefailure <=1s
Ignitionattempts 1-10
(*) The above times correspond toguaranteedvalues.Actual
values maydiffer from declared ones, as waiting (TW) or
prepurgetime(TP) maybelonger and safetytime(TS)
shorter.
Loadrating:
Gasvalve (EV) 0,25Acos ϕ≥0.5
Fan 0.5Acos ϕ≥0.5
Electricalpump 0.5A cos ϕ≥0.5
Deflectionvalve 0.5Acos ϕ≥0.5
220Vac modulating output 0.5Acos ϕ≥0.5
NB: Theboard is provided withaninputfilter; the total load
currentallowedbytheboard is2A;therefore thetotal load
mustbe lowerthanor equal tothis value. Therefore the sumof
applied loadshastobelowerthan2A.
Flame monitoring:
Theflamedetection device makes use oftherectification
propertyoftheflame.
Min. ionisationcurrent: 0.5µA(*)
Recommendedionisation
current: 3 ÷5 times the min.
ionisationcurrent
Max. cable length: 1m
(*)Asensitivityof 1,2 µAis alsoavailable.
Ignitiondevice
The ignitiondevice is remote (typeBrahmaTR2).
Type: TR2
Peak voltage with30 pF load: 15KV or 18 kV
Peak current: 800 mA
Spark frequency: 12 – 25 – 50Hz
(different frequenciesare
available onrequest)
Supplycable standardlength: 0.6 m
(different lengths are
available onrequest)
High voltagecablestandard
length: 0,2 m (different lengths are
available onrequest)
Siliconehighvoltage cable
withdiameter: 4mm
Electrodeconnection: cylindrical ∅4mm
(configurationuponrequest)
Recommendedsparkgap: 2-4 mm
Consumption: 2,5VA
Spark energy 20mJ
Max. operating temperature: 150°C
fig.1. RemoteIgnition Device: BRAHMA Type TR2

6609_r01 3/8
-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.

4/8 6609_r01
Earthconnection
OPERATING CYCLE
Thefollowingoperatingcyclereferstothetemperature
adjustmentsystem describedabove.
Thisoperatingcyclereferstoastandardexampleand canbe
customizeduponrequest.Thecyclerefers to aboardfitted
withthe controlpanelillustrated in fig.2.
Starting cycle
The startingcyclebeginsonheatdemandbytheroom
thermostat(heatingmode)orthewaterflowswitch (domestic
hot water mode).
Thewater pump isenergized, and ifthe water temperature is
lower thanthepreset value, aburner starting demandwill
occur.
Incase of aclosed-chamberboiler, thecontrolunitstartsthe
fanonly iftheairpressureswitchisin "no-air-flow" position;
whenitswitches into "air-flow"position,the prepurgetimeTP
begins, at theendofwhichthe gas valveissupplied, the
ignitiondeviceisstartedandthesafetytime TSbegins. Inthis
stage,theburnerheat capacityiskept atacontrolledvalue
according to the application requirements (soft start).
If aflamesignalisdetectedattheend ofTS, the temperature
adjustment processwillbegin,andtheburner flamewillbe
modulated inorder to reachthesamewatertemperature as
the presetvalue. If no flame signalis detectedwithin the safety
time,ontheelapsingof TSthegas valvewillclose. If the
numberofattempts iscompletedthe lockoutconditionoccurs,
otherwise there isanother ignitionattempt.Theboilerlockout
issignalledonthecontrolpanel; to reset thesystem pressthe
corresponding push-button.Ifhot water demandstill occurs,
the boiler will start a newignitioncycle; iftheconditions
leading tolockoutstill occur,theboilerwill gobackto lockout.
The boilerkeeps onrunning until eitherheatdemand stops, or
oneof thesafetydevicesswitches on,or the flame
extinguishes.
Domestic hot water mode
Ignitiondemandin DHWmode haspriorityover heatingmode.
Theboilerburner ignitionoccurs whenhot waterisdrawn;the
boiler willtryandsupplythe user withdomestichot waterat
presettemperature.Ifthe requiredcapacityislower thanthe
min.modulationcapacity,theboiler willperform shortignition
andturnoffcycles.Iftherequiredcapacityishigher thanthe
boiler max.capacity, the water temperaturewill beproportional
to thequantityof drawnwater,butlower thanpreset
temperature.
Heating mode
Iftheboiler isin winter position,andonroomthermostat
switchingofftheoutgoingwatertemperature islower than the
presetvalue,boiler ignitionwilloccur and flamemodulationwill
begin untilthe boilerreachestherunningcondition.Ifthe
outgoingwater temperatureis5°C higher thanthevalue
previouslyadjustedbytheuser,theboiler willswitch off; re-
ignitionoccurs assoonasthewater temperaturedrops of 5°C
belowthepreset value, provided thatat least 150sec have
elapsed fromtheboiler switching off. Theboiler max.capacity
in heatingmode issetduring installationthroughthepush-
buttonson the controlpanel.
Circulator overrun
Everytimetheboiler switches off(inheatingmode), the
circulatorkeepsonrunning forashorttime(5 seconds),in
order toavoidwateroverheatingin theprimaryheat
exchanger.Suggested overrun timesare,forexample: 30s,
60s or 180s.
J29
Boiler case
Earth Terminal
Earth forloads
(Pump, LoadingValve, Fan andGasValve)
Earthforbielettrodsystem
Twowire connection
Airpressureswitch:
Common (C)
Normal open(N.O.)
Line
Neutral
J34
J1
J7 J5 J20
J23
J2 J21
MOD.1
J4
F1
2AF
250Vac
J22
J30
J26 J28 J33 J32
J35
TR1
J25
1
JP5
JP4
JP3
JP2
JP6
Ioniazation fast-on
Earth connection
(fast-on)
Earth signal
Earthconnection
(fast-on)

6609_r01 5/8
WIRING DIAGRAM
Thewiringdiagramisillustrated infig.3at theend of this
paragraph. Followingsarethe connectors of the board and the
meaning of eachsignal
ifsomeofthe loads are not available,thecorrespondingpins
or allthe connectormaynotbefitted.
Board power supply connector
(J4–2-POLESTELVIO)
Pin1 Live
Pin2 Neutral
Earthconnectors
(J7, J34, J35 – 6,3 mm fast-on)
Pin1 Earth
Flame sensor connector
(J5–4,8 mm fast-on)
Pin1 Flamesensor
High-voltageloadconnector for diverting valve
(J20 – 9-POLEMOLEX)
Pin1 Neutral
Pin2 NC
Pin3 NO
Fanconnector
(J23 – 2-POLEMOLEX)
Pin1 Neutral
Pin2 Fan (on/off)
Pumpandmodulating loadconnector
(J21 – 4-POLEMOLEX)
Pin1 Water electricalcirculator
Pin2 Neutral
Pin3 Neutral
Pin4 230Vac auxiliarycontrol
Gasvalve connector
(J2–4-POLESTELVIO CFM4A)
Pin1 Live forEVGgas valve
Pin2 Safety thermostat
Pin3 Safety thermostat
Pin4 NeutralforEVGgasvalve
Incaseno safetythermostat is used,connectionis as follows:
Gasvalve connector
(J2–4-POLESTELVIO CFM4A)
Pin1 Notconnected
Pin2 Notconnected
Pin3 Live forEVGgas valve
Pin4 NeutralforEVGgasvalve
Airpressure switch and limit thermostat connector
(J22 – 5-POLELUMBERG 2,5MSF)
Closed-chamberconnection
Pin 1 Airpressure switch
Pin 2 Air pressure switch
Pin 3 Notconnected
Pin 4 Limitthermostat(*)
Pin 5 Limitthermostat
(*)If nolimitthermostat isused, pins1and2mustbe short-
circuited.
Connectorforcombustion productssafetydeviceand
limitthermostat
(J22 – 5-POLELUMBERG 2,5MSF)
Open-chamberconnection
Pin 1 Combustionproductsdischarge safetydevice
(*)
Pin 2 Not connected
Pin 3 Combustionproductsdischarge safetydevice
(*)
Pin 4 Limit thermostat
Pin 5 Limit thermostat
(*)Ifnocombustionproductssafetydevice isused, pins1and
3mustbeshort-circuited.
Modulationandflow switchconnector
(J32 – 9-POLELUMBERG 2,5MSF)
FLOWMETER FLOW SWITCH
Pin 1 NOTUSED NOTUSED
Pin 2 NOTUSED NOTUSED
Pin 3 EVGvalve modulator EVG valve modulator
Pin 4 EVGvalve modulator EVG valve modulator
Pin 5 Water pressure switch Water pressure switch
Pin 6 Water pressure switch Water pressure switch
Pin 7 Flowmeter input Flowswitch
Pin 8 Flowmeter +5Vdc Notconnected
Pin 9 Flowmeter 0Vdc Flowswitch
In casethe option"modulating fanlow-voltage PWMcontrol" is
operating(inthiscase theairpressureswitch is necessary),
the connector is thefollowing:
Modulationandflow switchconnector
(J32 – 9-POLELUMBERG 2,5MSF)
FLOWMETER FLOW SWITCH
Pin 1 Modulator +24Vdc Modulator +24Vdc
Pin 2 Modulator 0Vdc Modulator 0Vdc
Pin 3 EVGvalve modulator EVG valve modulator
Pin 4 EVGvalve modulator EVG valve modulator
Pin 5 Water pressure switch Water pressure switch
Pin 6 Water pressure switch Water pressure switch
Pin7 Flowmeter input Flowswitch
Pin 8 Flowmeter +5Vdc Notconnected
Pin 9 Flowmeter 0Vdc Flowswitch
In thisapplicationisnecessarytheuseof theAirPressure
Switch.

6/8 6609_r01
Pressure transducer connector
(J33 – 4-POLE LUMBERG 2,5MSF)
Pin1 +5Vdc
Pin 2 0Vdc
Pin3 +24Vdc
Pin4 Input
NTC temperature sensorconnector (*)
(J28 – 8-POLE LUMBERG 2,5MSF)
Pin1 Outside NTC
Pin2 Outside NTC
Pin3 HeatingreturnNTC
Pin4 HeatingreturnNTC
Pin5 Domestic hotwaterNTC
Pin6 Domestic hotwaterNTC
Pin7 HeatingNTC
Pin8 HeatingNTC
(*)Thefunctionof NTCs isdetermined by thetemperature
adjustmentprogram. Thisfunctioncanvaryaccordingto
specific customer's requirements.
Roomthermostat connector
(J28 – 2-pole screwconnector)
Pin1 Room thermostat
Pin2 Roomthermostat
Selectionjumpers
JP6 LPG/Naturalgas
JP2 Customizable (*)
JP3 Customizable (*)
JP4 Customizable (*)
JP5 Customizable (*)
(*) The function ofjumpers isdeterminedbythetemperature
adjustmentprogram. Thisfunctioncanvaryaccordingto
specific customer's requirements.
Timer connector
(J26 – 4-POLE JST)
Pin1 0Vdc
Pin2 +24Vdc
Pin3 Input/output TTL 1
Pin4 Input/output TTL 2
The remaining connectorshave thefollowing function:
1. J30:connector forinterfacecontrol panelconnection;
2. J25:connector forin-circuitprogramming of U9;
3. J8, J9,J10,J11, J12: connectors for expansionboard
connection(SE).
Inparticular,J30connects theboardtothecontrol panel,if
available. Anexample ofcontrolpanel isshownin fig.2.
In generalthe board candriveupto4seven segments
displays anditcan read up to7push-buttons.
Themeaningof eachpush-button canbe determinedby the
temperature adjustment program.
Only the resetbuttonhas tobefixed (asshown in fig.2).
fig.2.Anexample ofinterfacecontrol panel

6609_r01 7/8
PARTREFERENCES
Type description
384 (1) (2)(3)(4)(5) (6) (7)(8).(9) (10)(11)
(1) Powersupply: (7) Modulation:
P:Phase-sensitive device D: Nomodulation
N:Nophase-sensitive device
(2) Interfaces : (8) Thermostat:
E:Economical Y:Noroomthermostat
C:Expansiontype 386
(3) Communication : (9) Letterrefers toacustomer:
S:number of standard inputs (Brahma document)
M: Multiplexer
(4) Type of controlboard : (10) Type ofsoftware:
0: Nocontrol onboard 0,1,2…:progressive numbering
1: LCD
2: 2digits
3: 3digits (11) Softwareindex revision:
4: 4digits 00,01,02….:progressive numbering
(5) Type of controlcirculator :
X:Nothing
F:Phase-shift
U:Output220V
(6) Deflaction relays:
1: Fanrelay – no deflectionvalve relay
2: Fanrelay – deflection valve relay
3: Nofan relay – nodeflection valve relay
4: Nofan relay – deflectionvalve relay
PARTS REFERENCES OFTHEBOARD OPTIONS
Options(printed on thelabel)
(1) (2) (3) (4) (5)(6) (7)
Optionsdescriptions
(1) M: manualreset
E:electricalreset(standard)
(2) TP:0-120s (standard3s)
(3) TS:3-120s (standard7,5s)
(4) Fan:
F1:withoutfan(openchamber)
F2:withfan
F3:withfan (open/close chamber compatible) (standard)
(5) Power supplyconnection
Noletter: phase-neutral polarization(phase-sensitive control).
N:no-polarization(oneindependentphase relayandone independentneutraland flamedetection relay for
no-polarized ionization)(standard).
N1:one independentphase relay and one independentneutralandflamedetectionrelay for polarized
ionization
(6) Ignitionattempts
Noletter: one ignition attempt after a safetyshutdown(standard).
Ynn:multipleignition attempts(nn =1 – 10)
(7) Ignitiondevice andflame detection mode
Noletter: remoteignition device(TR2) andflame detection throughadedicatedelectrode
X1:remoteignitiondevice (TR2) and single-electrodeflame detectione(one electrodefor bothflamedetection
and ignition)

BRAHMAS.p.A
ViadelPontiere,31/32
37045 Legnago(VR) - ITALY
Tel. [phone] – Fax[phone]/01Subject toamendmentswithoutnotice
http://www.brahma.it
E-mail: [e-mail]
8/8 6609_r01
JP2
JP3
JP4
JP5
JP6
F1
2AF
250Vac
J32 J33 J28
J26
J10
J29
J22
J21J2J23J20
J5J7
J1
J4
11
1
1
1
1
1
1 1
MOD.1
J8
TR1
U1
L1
U6
U2
U9
U8
ION
+5Vdc
0Vdc
+24Vdc
INPUT
CH NTC PROBE
DHW NTC PROBE
CH RETURN NTC PROBE
OUTSIDE NTC PROBE
1
+5Vdc
0Vdc
FLOWMETER
INPUT
FLOWSWITCH
WATERPRESSURE SWITCH
GAS VALVE MODULATOR
PINUSEDIN
OPTIONM2
PRESSURE TRANSDUCER
ROOM
THERMOSTAT
LOCALUSERMANUAL
INTERFACE
TIMER
EARTH
NEUTRAL
LIVE
AUX 220Vac LOAD
PUMP
SAFETYTHERMOSTAT
GAS VALVE
FAN
N.C. N.O.
3-WAY VALVE
FLAME ELECTRODE
TR2
TOJ7
(IFMONOELECTRODETOJ5)
EARTH
LIMIT
THERMOSTAT
APS
COMBUSTION
SAFETYDEVICE
J34
EARTH
J35
J9
J11
J12
1
+24Vdc
0Vdc
Contacts
fig. 3.384 Wiring diagram(the dimensions are notinscale)
ATTENTION -> CompanyBrahmaS.p.A.declinesany responsibility for any damage resulting fromthe Customer's interferingwith thedevice