Monitor Products, Inc M2400 User manual

MONITORHEATINGSYSTEMS
Table of Contents
Section 1: Description
1-1 Specifications (M-2400)
1-2 SpecialFeatures(M-2400)
1 -3 SafetyFeatures(M-2400)
1-4 Specifications(M-2200)
1-5 Special Features(M-2200)
1-6 SafetyFeatures(M-2200)
1-7 Description
1-8 Spill Tray
1-9 HeaterCabinet
1-10CombustionSystem
1-11 CombustionChamber
1-12Burner Pot
1-13 Combustion RingAssembly
1-14FlameSensor
1-15 Igniter
1-16Combustion Air System
1-17 Flue Pipe
1-18 Combustion Blower Motor(M-2400)
1-19HeatExchanger
1-20 Air Circulation Fan
Page 1~10
1-21 Air PressureSwitch
1-22FuelDeliverySystem
1-23ExternalFuelTank
1-24 FusibleLinkValve
1-25FuelConstantLevelValve
1-26 SolenoidPump
1-27 ElectricalSystem
1-28 Microprocessor
1-29TemperatureSensor
1-30SafetyMechanism
1-31ClothCoveredExhaustPipe
1-32 Air Circulation Fan Guard
1-33Fuse
1-34 OverheatProtectorSwitches(M-2400)
1-35 Revolutioncontrol of
combustionblowermotor
1-36 CombustionBlowerMotor(M-2200)
1-37 OverheatProtectorSwitches(M-2200)
Elements of combustionsystem(M-2400)
Elements of combustionsystem(M-2200)
Section 2: Installation
2-1 Introduction
2-2 PhysicalPlacement of Heater
2-3 DrillingRequirements
2-4 PowerRequirements
2-5 FuelTankRequirements
2-6 TemperatureSensorWiring
Requirements
2-7 BuildingCodes
2-8 Un-packing
2-9 HeaterInstallation
Installation Classification(M-2400)
Page 11~27
InstallationClassification(M-2200)
ApplicableWallThickness of FluePipe
FluePipeClearances
2-10 Installing an Extension Kit
2-11 TypicalMonitorLifterPumpInstallations
2-12 Uses forthe ElbowAdapter Kit
2-13FuelTank Installation
2-14Heater Installation
Typicalfuellineconnections
Back guard(M-2400)
Backguard(M-2200)
Section 3: Operation •
3-1 Introduction (M-2400)
3-2 OperatingSpecifications(M-2400)
3-3 Introduction(M-2200)
3-4 OperatingSpecifications(M-2200)
3-5 Operating Controls and Indicators
3-6 Pre-operation CheckList
3-7 Operation
3-8 ManualHeaterOperation
3-9 Automatic Heater Operation
Page 28~38
3-10 Programming the weeklytimer
for automaticheateroperation
3-11 HeatSensor
3-12 MonitorShutdown
3-13 Out of Fuel
3-14 Recoveryfrom a Power Failure
3-15 RecoveryfromOverheatCondition
3-16 RecoveryfromBlownFuse
3-17Operation Control system
M-2400/2200 Operationtimingchart

MONITORHEATINGSYSTEMS
Table of Contents
Section 4: Maintenance Page 39—42
4-1 Introduction 4-6 CleaningFusibleLink Valve Intake
4-2 PeriodicMaintenance 4-7 CorrectiveMaintenance
4-3 InspectExhaust /Air Piping 4-8 Replacement of Fuses
4-4 Verify Igniter Operation 4-9 FuelContamination
4-5 CleanFuelConstantLevel
Valve Filter
Section 5: Servicing Page 43—47
5-1 Introduction
5-2 Measurement of FuelFlowrate
5-3 Removal of WaterDeposits and Contaminants
from FuelConstantLevelValve and FuelLines
5-4 Cleaning the BurnChamber & Burner Pot (M-2400)
5-5 Cleaning the FuelInlet(M-2400)
5-6 Cleaning the BurnChamber & Burner Pot (M-2200)
5-7 Cleaning the FuelInlet(M-2200)
Section 6 : Troubleshooting Page 49~62
ResistanceValues(M-2400)
ComponentVoltageReadings(M-2400)
Resistance Values(M-2200)
ComponentVoltageReadings(M-2200)
Test PointVoltage
TroubleshootingDiagrams(Mechanical)
TroubleshootingDiagrams(Electrical)
Indication of Failure mode
Section 7 : Electrical System Page 63—66
Schematics
Schematics(sinceFebruary2004)
Monitor2400PrintedCircuitBoardWiringDiagram
Monitor2200PrintedCircuitBoardWiringDiagram
SERVICE PARTS LIST • Page 67-70
Monitor2400Servicepartslist
Explodedviews(M-2400)
Monitor2200Serviceparts list
Exploded views (M-2200)

MONITOR HEATING SYSTEMS
Section 1: Description
1-1 SPECIFICATIONS
Model
FuelType
Heater Efficiency
Heat Rating
Heater Output
FuelTank
Fuel Consumption
Power Source
Power Consumption
Heated Air Delivery
Vent PipeHole
Dimensions
Weight
*Net Efficiency is 88%,A.F.U.E. is84%
Monitor 2400
Crystal Clear Kerosene
93%*
High : 43,000BTU/hour
H.Medium : 32,000 BTU/hour
L.Medium : 24,600BTU/hour
Low: 16,200 BTU/hour
High : 37,200BTU/hour
H.Medium: 26,900BTU/hour
L.Medium: 20,700BTU/hour
Low: 13,600 BTU/hour
Separate (Notsuppliedwithheater)
High : 0.319 Gallon/hour
H.Medium: 0.24Gallon/hour
L.Medium: 0.18 Gallon/hour
Low: 0.12Gallon/hour
120 Volts AC ;60Hz
Ignition :310 Watts
HighcombustionOperation :68 Watts(Average)
High toLow4 steps combustion : 56.5 Watts(Average)
Operations
High :388 Cubicfeet/minute
H.Medium :388 Cubicfeet/minute
L.Medium :330 Cubicfeet/minute
Low :300 Cubicfeet/minute
-inchesDiameter
Height: 26.6inches
Width: 28.7inches
Depth : 14.0 inches
82 Pounds,empty
1-2 SPECIALFEATURES
AUTOMATIC IGNITION
MEMORY BACK UP: Set Memory canbe kept in
case of power failure forupto30 minutes.
DUAL BLOWERS : Separatefans for combustion
and room air circulation.
THERMOSTATICALLY CONTROLLED : Adjusts to
the desiredroomtemperature.
BUILT-INTIMER : Heater will automaticallyoperate
as programmed bythe user.
AUTOMATIC RESETAFTERPOWERFAILURE :
Heater will automaticallyresumeoperationafter
power is restored.
INDICATOR LIGHTS : Easy-to-see signalsshow
whenheater isin operation,whentimer is activa-
ted, and when the burner is operating.
CHOICE OF FUELSUPPLY : Connect to separate
tank.
MULTIPLEHEATEXCHANGER : Extracts 88%of
heat fromburner.
CLEAN OPERATION : Products of combustion are
ventedoutside.
CONSUMES NO RpOM AIR: Airfor combustion is
drawn from outside.
EASY INSTALLATION : Includes all partsrequired
for standard installation.
CHILD LOCK : Preventsaccidentaloperation and
prevents small children from altering the controls.
1-3 SAFETYFEATURES
SAFE RE-LIGHTING : Heater will not restart until its
combustionchamber has cooled.
ELECTRICAL PROTECTION : Heaterautomatically
shuts offinthe unlikely event ofa malfunction in
the electrical circuitry or disruption ofthe power
supply.
NO EXHAUST IN ROOM : Products of combustion
are dischargedoutdoors.
FLUEPIPE : Outside airis drawnthrough a pipe-
within-a-pipe ventingsystem.Thisprocess pre-
heats combustion air and regainsheatfrom ex-
haustgases.
ZLCAUTIONiALTERNATE POWER
SOURCES
The Monitor2400 maynot operatewhenpow-
ered by sourcessuch asan auxiliarygenerator,
UPS (UninterruptedPowerSource),inverters,
etc.Checkwithyourdealer for guidance on spe-
cific applications.

MONITOR HEATING SYSTEMS
Section 1: Description
1-4 SPECIFICATIONS
Model Monitor 2200
FuelType
Red dyed or ClearKerosene orLow Sulphur *1Oil
Heater Efficiency
93%*
Heat Rating
High : 22,000 BTU/hour
H.Medium : 17,400 BTU/hour
L.Medium : 12,400BTU/hour
Low: 9,600BTU/hour
Heater Output
High: 18,260BTU/hour
H.Medium : 14,440BTU/hour
L.Medium : 10,290BTU/hour
Low: 7,970BTU/hour
Fuel Tank Separate (Capsule tankoptional)
FuelConsumption
High: 0.164 Gallon/hour
H.Medium : 0.13Gallon/hour
L.Medium : 0.19 Gallon/hour
Low: 0.07 Gallon/hour
Power Source
120 Volts AC; 60Hz
Power ConsumptionIgnition
:250 Watts
Operations :41 Watts(Average)
Heated Air DeliveryHigh
: 176 Cubicfeet/minute
H.Medium : 176 Cubicfeet/minute
L.Medium : 126 Cubicfeet/minute
Low : 113 Cubicfeet/minute
Vent PipeHole inches Diameter
Dimensions Height: 26.0inches
Width : 20.9inches
Depth : 13.0 inches
Weight
55 Pounds,empty
* When consideringheat of condensation is lost,then thenet efficiency is 88%,A.F.U.E. is84%
1-5 SPECIALFEATURES
AUTOMATIC IGNITION
MEMORY BACK UP: Set Memory canbe kept in
case of powerfailure forupto30 minutes.
DUAL BLOWERS : Separatefans for combustion
and room air circulation.
THERMOSTATICALLY CONTROLLED : Adjusts to
the desiredroomtemperature.
BUILT-INTIMER : Heater will automaticallyoperate
as programmed bythe user.
AUTOMATIC RESETAFTER POWER FAILURE :
Heater will automaticallyresumeoperationafter
power is restored.
INDICATOR LIGHTS : Easy-to-see signals show
when heater isin operation,whentimer is activa-
ted, and when the burner is operating.
CHOICE OF FUELSUPPLY : Connect to separate
tank or capsuletank optional.
MULTIPLEHEATEXCHANGER : Extracts 88%of
heatfrom burner.
CLEAN OPERATION : Products of combustion are
vented outside.
CONSUMES NO RpOM AIR: Airfor combustion is
drawn fromoutside.
EASY INSTALLATION : Includes all partsrequired
for standard installation.
CHILDLOCK : Preventsaccidentaloperation and
prevents smallchildrenfrom altering the controls.
1-6 SAFETYFEATURES
SAFE RE-LIGHTING : Heater will not restart until its
combustionchamber has cooled.
ELECTRICAL PROTECTION : Heaterautomatically
shuts offinthe unlikelyevent ofa malfunction in
the electricalcircuitry or disruption ofthe power
supply.
NO EXHAUST IN ROOM : Products of combustion
are discharged outdoors.
FLUE PIPE : Outside airis drawnthrough a pipe-
within-a-pipe ventingsystem.Thisprocess pre-
heats combustion airand regainsheatfrom ex-
haustgases.
&CAUTION:ALTERNATE POWER
SOURCES
The Monitor2200 maynot operatewhenpow-
ered by sourcessuch asan auxiliarygenerator,
UPS (Uninterrupted Power Source), inverters,
etc.Checkwithyourdealer for guidance on spe-
cificapplications.

MONITOR HEATINGSYSTEMS
Section 1: Description
1-7 DESCRIPTION
The Monitorheaters are composed ofthe following:
a spill tray, a cabinet, a combustionsystem, anair
circulationsystem, a fueldeliverysystem,electrical
and electronicssystems anda variety of safety
mechanisms.
1-8 SPILL TRAY
The Spill Tray:
— Protects the floorfromdamageresultingfrom
fuel spillage.
— Provides a secure, tip-resistant heaterbase.
Metalretainers (2) secure the heater tothe Spill
Tray.
The legs are positionedwith inthe circularindenta-
tions.
1-9 HEATERCABINET
A steel cabinet holds and protects all internal com-
ponents.
A number of primaryparts are assembled to form
this housing.
1-10CMBUSTIONSYSTEM
The CombustionSystem is responsible forthe pro-
duction of heatwhich is circulatedinto the room .
Inthe CombustionSystems a mixture of fuel andair
is burned to produce heat. Airis drawnfromoutside
the dwelling into the Combustion Chamber. Atthe
same time,fuel is metered from a storagecavityinto
thissameCombustionChamber. Within the cham-
ber, the air/fuelmixture is ignited to produceheat.
The Monitorcombustionsystems are safeguarded
by a pair of overheatprotectorswitches;They will
shutdown the heater (to protect it fromdamage) in
the event of excessiveheat build-up. The overheat
protector switchesresetautomaticallyafter cooling
down.
1-11COMBUSTIONCHAMBER
This tall cylinder is positioned onthe HeaterBase. It
is secured tothe base by phillips headscrews.
Connected tothe CombustionChamber aretheig-
niter,(locatedwithin the chamber) a fuel line, the
Heat Exchanger, anda FlameSensor.
Within the CombustionChamber arethe BurnerPot,
the CombustionRingAssembly.Access to those in-
ternally-locatedparts is facilitated bya removable
Service panel.
A Window onthe panel lets the technician visually
examine the combustion process(i.e. glowingigniter
or properflamecolor).
An airway, inthe CabinetBase,extendsfrom thein-
take fanofthe CombustionBlower tothe hollow
base ofthe CombustionChamber. This airwaychan-
nels airtothe CombustionChamber.
The FlameSensor is mountedwith two(2) phillips
headscrewsonto the wall ofthe Combustion Cham-
ber.
1-12 BURNER POT
Designedspecifically to supportcombustion, the
Burner Pot (refer to Figure 1-2/1-3) contains a series
of air holes, an ignitertube (to accommodate theIg-
niter), anda fuel inlet fitting (interconnects the fuel
line). It is secured toa mountingplatenear the bot-
tom ofthe CombustionChamber.
The CombustionRingAssembly is seated on three
(3) screws or pins inthe BurnerPot.
1-13COMBUSTIONRING ASSEMBLY
Thisassembly isa specialstructure,designed to
promoteefficientcombustion.
1-14FLAME SENSOR
Mounted onthe outsidewall of CombustionCham-
ber, the FlameSensoralwayssupervises the flame.
1-15IGNITER
Locatedwithin the ignitertube ofthe BurnerPot, the
Igniter is designed to pre-heat the Burner Potandto
vaporize and ignite the air/fuelmixture to start the
combustionprocess.
The Igniter is secured bya bracket and screw tothe
ignitertube. The coverplate is secured tothe com-
bustionchamber by three (3) phillips headscrews.
1-16COMBUSTION AIR SYSTEM
The Combustion Air Systemchannels airtoand from
the heater.
Outside airis drawninto the heater bythe Combus-
tion Blowerthrough an airway tothe Combustion
Chamber.
A CombustionBlowerdraws the intake airin
through a FluePipe.This air enters the Combustion
Chamber atthe Burner Potand mixeswith the fuel
to support combustion, Remaining airis heated and
is drawn into the HeatExchanger.
As the heated air passesthrough the HeatExchan-
ger, anAir Circulation Fan blowsroom air past the
Heat Exchanger andout againinto the room,heating
passing airby convection.Exhaustvapors exiting
from the HeatExchanger are ventedthrough the
Flue Pipe.
A deterioration ofair pressure attheAir Pressure
Switch isan abnormalcondition; the heater is shut
down bythe malfunction.

MONITOR HEATING SYSTEMS
Section 1: Description
1-17 FLUE PIPE
The FluePipes is adaptable in three (3) sizes.This
provides the flexibility to meet the installation re-
quirements for walls of variousthicknesses.
The FluePipe istwo Sections,Fluepipe A and Flue
pipeB.
The FluePipe A contains a "T"-shaped fittingcon-
sisting of four ports.Thisside is mounted onthein-
terior wall ofthe dwelling. The FluePipe B is vented
outside the dwelling. The Flue Pipe Assemblycon-
sists oftwo concentrictubes.Outside airis drawn
through the cylindricalspacebetween the tubes.
Combustionby-products are ventedthrough thein-
ner tube.
As the cool air enters, itis heated bythehotair that
is exiting the system.
A large-bore, flexible hoseconnects theair inlet port
on the FluePipe A with the CombustionBlower; a
cloth-coveredmetalpipeconnects the Combustion
Blower with the exhaustoutlet onthe FluePipe A.
IMPORTANT: If extensionkits are utilized, usethe
correct damper in accordance with the instructions in
table 2-1of page 14
1-18COMBUSTION BLOWER MOTOR
The combustion blower hasa fourstageintake fan
Burnermodescontrol fan speeds.
The combustion air controls areas follows:
Table 1-1 COMBUSTION AIR CONTROL (M-2400)
Burn Mode
Fan Speed (r.p.m.)
High
2,800
Medium-High2,300
Medium-Low
1,900
Low
1,500
Pleaserefer to paragraph 1 -35in page? forthe de-
tails ofthe combustionblowermotorcontrol.
1-19 HEAT EXCHANGER
An inlet atthetopofthe HeatExchangerpermits the
heated airto travelfrom the CombustionChamber
into the exchanger.
An outlet, atthe bottom ofthe exchanger,permits
combustionby-products tobe vented tothe Flue
Pipe.
air within the exchangerheats the outsidemetal
walls. Thehot metalwalls, in turn,heat air that is
pushed past the exchanger andis circulatedinto the
room. Anair baffle,directly in front ofthe exchanger,
deflects the heated air upwards, and out,through the
louver assembly.
A pair of Over-HeatProtectorSwitchesprotect the
heater from damage dueto excessiveheatbuilt-up.
1-20 AIR CIRCULATION FAN
Circulationfans are driven by three-speedmotors
andare designed to circulate the heatedroomair.
If the heater is running inlow burnmodes, thefan
also runs at low-speed; in medium-lowburnmode,
thefan runs at medium-speed; in medium-high or
highburnmodes, thefan advances to highspeed.
Operation ofthefanis controlled bythe micropro-
cessor andfan thermostatswitch.
Physicallyassembledwith a protectivewirecage for
the heater, the entire fan assembly is secured toa
bracket onthe rear ofthe HeaterCabinet.
A metalconduit, atthe rear ofthe heater,protects
the fan wiringfromdamage.
1-21 AIR PRESSURE SWITCH
This switchconsists ofa rubberdiaphragmwhich
senses changes inair pressure(it is connected tothe
CombustionBlower) andisa normallyopen,micro
switch.
Should an abnormalpressuredifferentialexist, the
switchopens to disable the circuitrythatcontrols the
supply of fuel. Since the flow of fuel tothe Burner
Pot iscut off, the flame extinguishes (after all fuel
currently inthe line has beenconsumed), andthe
code fE14jis indicated inthe digital display.
This safety mechanism canbe triggered by several
conditions:
— Leak or loose connection inair line
— Leak,loose, or broken tubing whichconnects the
Air PressureSwitchwith the CombustionBlower
— Clogged or blocked Air Line
— Blocked or cloggedFluePipe
— IntakeportCombustionBlower is blocked.
— CombustionBlower is inoperable
— Clogged or block air/intake hose.
Whilemovingthrough the HeatExchanger, thehot

MONITORHEATINGSYSTEMS
Section 1: Description
1-22 FUEL DEUVERY SYSTEM
Fuel Delivery isa very important aspect ofthe
Monitor's operation.
The fuel flowmust be maintained ata levelcorre-
sponding tothe burnmode, so that combustion can
be conductedefficiently.
Fuelmoves by gravity-flow from the externalfuel
storage tank orthe capsulefueltank tothe Fuel
ConstantLevelValve.
The SolenoidPumpmeters the flow of fuelfrom the
FuelConstantLevelValve tothe BurnerPot.
The meteredflow of fuel is carried tothe Burner Pot
by a copperfuel line.
1-23 EXTERNAL FUELTANK
Fuel forthe Monitors canbe stored in, andfed from
an externalstorage tank. The tank, whichgenerally
is dealer installed, should contain a shutoff valve, a
fuel filter anda vent. Installation ofthe tankshould
conform to local regulations andtothe specifica-
tions and guidelines documented in this Service
Manual.
1-24FUSIBLELINK VALVE
Basically, the FusibleLinkValve isa safetymecha-
nismthat cuts-off fuel tothe heater inthe event of
an overheat condition atthe valve.
In M-2400/M-2200, Fusible Link Valve isnot instal-
led, If necessary, itcanbe installed outside ofthe
appliance.
The FusibleLinkValve isa springloaded devicethat
cuts offthe supply of fuel tothe heaterwhen the
temperaturelevel (atthe valve)
exceeds a predefinedmaximum limit.
An inlet onthe bottom ofthe valve allows fuel to
pass into the heater. The handle-which can also
manually be opened or closed-sits ona spring-
loadedstemwhichcontains a low-meltingpoint
alloy.
Fuel enters the FuelConstant Level Valve through
an inlet atthe bottom ofthe reservoir. Asthe level
of fuelrises, it passesthrough a filter(which
removes most particles and foreignmatter from the
fuel), flows up through an openinletvalve and
enters the tank.
IMPORTANT: The Fuel Constant Level Valve filter
should be cleaned or replacedperi-
odically. Time intervals willdepend
on purity and quality of fuel.
Within the Valve, a floatmechanismcontrols the
level of fuelthatwill be permitted tothe reservoir. As
the fuelleveldrops, the floatdropsdown to increase
the inlet valveopening to admit more fuel into the
valve. When the fuellevelreaches its maximum
volume, the float rises to shut the inletvalve.
Inthe event that fuel within the reservoir rises toan
abnormallyhighlevel, a floatwithin the reservoir
rises to trip a safetymagnet.Thissafetymagnet
locks outthe float to preventfuelfromentering inthe
reservoir.
Should a foreignsubstancecause the inlet valve to
stick (or prevent it fromopening), the Fuel Set Lever
is utilized to free the valve andto admitfuel tothe
reservoir.
A CAUTION: Care must be taken to prevent
dust, dirt, or otherdebrisfrom
clogging or blocking the inlet
valve. If debriscollects onthe
seat ofthe inlet valve itmay
cause tripping ofthe safety lever
and will requirecleaning.
1-25 FUEL CONSTANT LEVEL VALVE
Thisvalve hasan automaticshutoffsafetymecha-
nism anda Fuel Set Lever. The safetymechanism
prevents fuelfromflooding or overflowing from the
fuel reservoir. The Fuel Set Leverresets the float so
the FuelConstantLevelValve can resumeopera-
tion.
The fuelreservoir isa tankwhichcontains a float
assembly, a safetymechanism, anda priminglever.

MONITORHEATINGSYSTEMS
Section 1: Description
1-26 SOLENOID PUMP
The SolenoidPump,mounted onthe Fuel Constant
Level Valve, and controlled bya microprocessor,
delivers four fuelflowmodes(High,Medium-High,
Medium-Low, Low) tothe BurnerPot.
1-27 ELECTRICAL SYSTEM
Electrical power is supplied tothe Monitor torunthe
Microprocessor andthe other electrically-energized
component.
Electricaloperation ofthe Monitor canbe thought of
as having the following eight(8) distinct phases.plug
in; turn-on; pre-purge/pre-heat; ignition;pre-
combustion; heating; Shutdown and post-purge.
All electronicdiagrams,Such as wiringdiagram,
circuit boardlayout, and electrical schematic canbe
found in Section 7 of thisServiceManual.
1-28 MICROPROCESSOR
Principallyconsisting ofa 64-pin Integrated Circuit,
the Microprocessorprovidessafetytimings,controls
relays and provides clock and thermostatfunctions
for the Monitorheater. A componentlayout ofthe
Printed CircuitBoard is found in Section 7 of this
Service Manual.
1-29 TEMPERATURE SENSOR
The sensor which is capable of sensing room tem-
perature within a range of 42"F to 96°F, canbe left
mounted onthe back ofthe heatercabinet orbe
wallmounted.
Approximately 4/^'(about 140cm)ofNo.22AWG
Wire is suppliedwith the sensor to facilitatewall
mounting the sensor ina favorablelocation.
1-30 SAFETY MECHANISMS
Several safetymechanismshavebeenbuiltinto the
Monitor HeatingSystem.Thesedevicesprotect the
user againstpersonal injury, protect the heater
against damage, and shutdown the heater ifa
malfunctionoccurs.
During installationmake sure that all Exhaust Lines
are tight. Donot operate the heater without the
insulatingcovers.
1-32 AIR CIRCULATION FAN GUARD
Thisguard isan integral part ofthefan assembly.
The guardprotects the user againstphysicalinjury
whichcouldoccur from accidentalcontactwith
revolving metal fan blade.
1-33 FUSE
2-amp. and 10-amp., 125VAC, fusesprotect the
heater from damageresulting from poweroverloads.
In the event ofa powersurge or internalwiring
hazards, the fuse opens and power tothe heater is
cut off.
The electricaloutletintowhich the heater is con-
nectedshould be protected byat least a 15-amp.
fuse or circuitbreaker.
1-34 OVERHEATPROTECTOR SWITCHES (M-2400)
Connected in series, two(2) normally-closedOver-
heat ProtectorSwitchessafeguard the heaters
againstdamage dueto overheating.
The switches are rated 115'C (239'F). Should a
Monitoroverheat(internaltemperatures rise beyond
115'C (239'F)).either or bothswitcheswillopen to
shutdown the heater. After extinguishing the flame,
the code FE14J is indicated inthe digitaldisplay.
The OverheatProtectorSwitches will automatically
reset after coolingdown.
Once the heater has cooled to 90'C (194*F), the
system canbe restarted. To restart the Monitor,
proceed as follows:
A. PressON/OFFSwitch to OFF.
B. Allowheater to cool.
C. Troubleshoot the cause ofthe overheat.
D. Press ON/OFFswitch toON
E. Proceedwithnormaloperation.
1-31 CLOTHCOVEREDEXHAUST PIPE
Insulatingclothcovers aretobe placed over all
metalsurfaces ofthe Exhaust Line during installa-
tion.
Since combustionby-products are vented at ele-
vated temperatures, the ExhaustPipewillbecome
hot duringoperation. The insulating cloth covers
protect the userfromburnhazardsassociatedwith
accidentalcontactwiththeseheatedmetalsur-
faces.
6

MONITOR HEATINGSYSTEMS
Section 1: Description
1-35 Revolution control of combustion blower motor
IC4
TRIAC L fSfj 1 Hole 1C
01 JT
Fig. 1-1
-o 5V
microprocessor
As shown in Fig.1-1, the current-carrying ratio forthe
combustionblowermotorshall be performed bythe
phase control, TRIAC, Q1.
The combustionblowermotor hasa built-in hole 1C
of whichinputsignal is entered tothe microproces-
sor through the comparatorIC8.
The hole 1C outputs the pulsesignal by6 pulse ev-
ery one revolution ofthe motor. The microprocessor
countsthispulse signal to obtain the number of
pulse,frequency perone second, and thencompute
the motor revolution -per one minute by this frequen-
cy.
In order to achieve the targetcontrolrevolutions
shown in Table1-1/1-2,Page4/8, the current-carry-
ing ratio tothe motorshall be controlled by TRIAC,
Q1 to make the revolution ofthe combustionblower
motor constant.
If the revolution ofthe combustionblower has
sloweddown to lessthan1200 (rpm), an abnormal
revolution will be sensed and then the heateropera-
tion will be stopped indicating the errorcode of (EOS)
inthe displaywindow.