MTM Heat EC 200, EC 300, GE 360, GE 400, GE 600 User Manual
DIESEL SPACE HEATER - SERVICE MANUAL
INDEX
1. CONTROLS AND COMPONENTS
2. FLAME CONTROL CYCLES
3. MAINTENANCE SCHEDULE
4. REPAIR PROCEDURES
1. FAN MOTOR ASSEMBLY
2. FUEL FILTER ASSEMBLY
3. FUEL PUMP ASSEMBLY
4. ELECTRIC PANEL ASSEMBLY
5. AIR PRESSURE SWITCH
6. COMBUSTION HEAD ASSEMBLY
7. COMBUSTION CHAMBER
8. COMBUSTION TEST
5. TROUBLESHOOTING GUIDE
6. WIRING DIAGRAMS
7. TECHNICAL SHEETS
EC 200 – EC 300
GE 360 – GE 400 – GE 600
L-S 102.00-BM
WARNING
The operations described in this booklet must be carried out by qualified and instructed personnel only.
Incorrect maintenance may result in improper operation and serious injury.
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1 COMBUSTION CHAMBER
3
5
8 9 10
12
18 20 19
1 2 3 4 6 7 5
8
9 10
12
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1. CONTROLS AND COMPONENTS
INDIRECT HEATER WITH STACK:EC 200 – EC 300
DIRECT HEATER WITHOUT STACK:GE 360 – GE 400 – GE 600
CONTROL PANEL
2
1
22
21
4 6 7
11
11
20 19
18
13
14
15
17
16
2 BURNER ASSEMBLY
3 NOZZLE
4 FUEL VALVE
5 DIESEL PUMP
6 MOTOR
7 FAN
8 FUEL FILTER
9 FUEL CIRCUIT
10 FUEL TANK
11 FUEL TANK PLUG
12 DRAIN PLUG
13 RESET BUTTON/LAMP OF
CONTROL FLAME
14 MAIN SWITCH
15 ROOM THERMOSTAT PLUG
16 CONTROL LAMP
17 POWER CORD
18 OVERHEAT THERMOSTAT
19 AIR PRESSURE SWITCH GAUGE
(LOW PRESSURE SIDE)
20 AIR PRESSURE SWITCH GAUGE
(HIGH PRESSURE SIDE)
21 FLAME DETECTOR (PHOTOCELL)
22 STACK
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CONTROL SYSTEM
The heater has all operational controls located in a watertight control panel mounted on the lateral side of the unit.
The control panel consists of:
• a 3-position switch for heating function: normal operation, stop or thermostat operation
• plug to connect a remote room thermostat
• power cord
• high voltage transformer that generates a spark to ignite the flame
• control flame box to handle starting / running cycle (see paragraph 2.).
The control flame box is equipped with a reset
The control system utilizes:
• a safety shut off switch that is a overheat thermostat shutting down the unit if the temperature of combustion
chamber and outlet air exceed the maximum allowed level
• an air pressure switch, that stops the unit if the air flow is not sufficient for combustion.
• a flame detector, that is a photocell monitoring constantly the flame presence and its integrity.
• a pair of ignition rods to create the ignition spark
FUEL SYSTEM
The fuel system consists of:
• fuel tank, that is steel, corrosion proof
The fuel tank hase a drain plug located underneath it to allow discharge of residual fuel before cleaning.
• fuel filter
• fuel pump. A screw fitted on the fuel pump allows the adjustment of fuel pressure setting
• fuel ON/OFF solenoid valve
o during normal operation the valve is open and the pressurized fuel flows to the nozzle, where it is
atomized, mixed with primary combustion air and ignited by the electrode spark
o during abnormal operation (see paragraph 2.) the flame control unit closes the fuel solenoid valve and
the unit stops.
• fuel circuit, including suction and return hoses from fuel tank to fuel pump and high pressure microhose from
fuel pump to nozzle
• burner head
• nozzle
COMBUSTION CHAMBER
For indirect heater it consists of:
• the internal combustion chamber (stainless steel made) that containing the flames and
• the external high efficient heat exchanger (aluminated steel made), that leads smokes to chimney / stack.
For direct heater it consists of the internal combustion chamber (stainless steel made) that containing the flames and
exhanges heat with the main airflow stream.
BURNER HEAD
The burner head is the assembly that determines the correct mixing of combustion air and fuel inside the combustion
chamber and it consists of:
• Fuel nozzle
• Nozzle support
• Flame diffuser
• Air opening baffle: a screw fitted on the burner head allows the adjustment of combustion air setting
• Ignition electrodes
• Flame detector
FAN – MOTOR ASSEMBLY
The electric motor drives the fuel pump assembly and a fan which blows air inside and around combustion chamber.
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2. FLAME CONTROL RUNNING / FAILURE CYCLE
2.1 STARTING CYCLE
The flame control unit starts the sequence of operation after a heating request (normal operation or thermostat
operation) and it consists of the following steps:
• Self-test (less than 3 s): self-check of electronics efficiency;
• Purging time TP (20 seconds): fan motor and ignition transformer are simultaneously switched on while the fuel
valve remains closed to eliminate any fuel or unburnt residual.
During the purging stage, the flame signal is constantly monitored and any kind of failure leading to combustion
prevents the burner ignition.
In case of heating request opening (room thermostat opening), the control unit goes to stand-by position. The
device remains in this status till closing of the room thermostat;
• Safety time (5 seconds): at the end of the purging time TP, the fuel valve is switched on and opens the fuel to
the nozzle.
In case of flame detection failure by the end of the TS safety time, the control unit goes to lockout, and the fan
motor, the ignition transformer and the fuel valve are de-energized, while the lockout signal is enabled.
Otherwise, at the end of the TS safety time the control unit disables the ignition transformer and goes to running
position.
• At the end of the TS safety time the control unit keeps the ignition transformer operating for about 30 s.
2.2 SHUT OFF CYCLE
When the heating request (normal operation or thermostat operation) opens:
• fuel valve and ignition transformer are switched off and the flame lights off;
• burner fan operates a 90 s post-purge ventilation
Restoring the heating request causes the post-purge to be interrupted and the starting cycle to be performed.
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2.3 FLAME FAILURE DURING STARTING CYCLE
If during the safety time TS, the photocell monitors a flame failure (signal to photocell become lower than
minimum), at the end of safety time the unit goes in lock out condititon:
• burner fan, ignition transformer and fuel valve are de-energized;
• alarm lamp on reset button becomes red
Unit can re-start only if pressing the reset button
2.4 EXTRANEOUS LIGHT OR FLAME DURING PRE-PURGE TIME TP
If during the pre-purge time the photocell monitors any residual flame then the unit goes in stand-by condition:
• burner fan goes on to purging combustion chamber
• fuel valve and ignition transformer are de-energized
• reset lamp is off;
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2.5 FLAME FAILURE DURING RUNNING STATUS (ONE TRIAL RECYCLING)
In case of flame failure in running status, the flame control unit make one trial restarting the unit.
If the reason of flame failure is confirmed, then the unit stops in lock-out mode, and the reset lamp becomes red.
2.6 RESET LAMP COLOR
WARNING
The reset button may have different colours:
• light off: unit is in stand-by status, waiting for heating request.
• steady orange light: function not active
• steady green light: unit is working normally (starting cycle or working cycle)
• steady red light: the heater stops permanently in lock-out status and can restart only if reset button is
pressed.
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3. MAINTENANCE SCHEDULE
Periodic maintenance of the heater is necessary to ensure proper performance and to prevent failures and it shall be
performed at the following periodic intervals:
• Daily maintenance
i. Inspect air inlet / air outlet and exhaust stack, remove debris if any
ii. If any air hose is installed, secure it is fixed. Minimize bends and keeps ducts straight
iii. Verify fuel tank is full
iv. Verify that exhaust stack is properly installed
• Weekly maintenance
i. Disassemble, inspect and clean fuel filter with clean fuel
ii. Remove top cover and clean the motor, fan blade and the interior shell
iii. Inspect the fuel hose assembly and check for any leaks
• 6 months maintenance
i. Disassemble burner head
1. Inspect and clean burner diffuser
2. Inspect and replace nozzle if necessary
3. Clean ignition electrodes and adjust settings
4. Check air combustion setting
ii. Check overheat thermostat
iii. Inspect and clean the combustion chamber
iv. Open electric board, inspect electrical components and check connections
v. Check fuel pressure setting of fuel pump
vi. Inspect and test the burner
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