Market Forge MT-25EO Service Manual
MT 25/40/60 GALLON SERIES
MODULAR BASE ELECTRIC TILTING KETTLES
PARTS AND SERVICE MANUAL
EFFECTIVE OCTOBER 11, 2016
The Company reserves the right to make substitution in the event that items specied are not available.
ERRORS: Descriptive and/or typographic errors are subject to correction.
44 Lakeside Avenue, Burlington, Vermont 05401 USA Telephone: (802) 658-6600 Fax: (802) 860-3732
Superseding All Previous Parts Lists.
MARKET FORGE INDUSTRIES
www.mi.com
P/N 14-0331 Rev D
TABLE OF CONTENTS
GENERAL TROUBLESHOOTING .......................................................3
PRESSURE CONTROL SWITCH ADJUSTMENT .........................................5
COLD WATER CONDENSER & LID COUNTERBALANCE ADJUSTMENT ..................6
HEATING ELEMENT REPLACEMENT ...................................................7
WATER CONTROL BOARD TESTING PROCEDURE .....................................8
WATER LEVEL CONTROL ADJUSTMENT ............................................. 10
DRAW-OFF VALVE REPAIR ...........................................................11
TILTING MECHANISM REPAIR ....................................................... 12
WIRING DIAGRAM ................................................................... 13
SCHEMATIC ......................................................................... 14
ILLUSTRATED PART LIST
PRESSURE SWITCHES .............................................................. 15
DRAIN ASSEMBLY ................................................................... 16
TILTING MECHANISM ................................................................ 17
PISTON ASSEMBLY ................................................................. 18
VALVE AND FAUCET ................................................................. 19
LOW WATER CUTOFF ............................................................... 20
CRANK SHAFT ...................................................................... 21
BOILER BASE ASSEMBLY ........................................................... 22
ELECTRICAL COMPONENTS ........................................................ 23
VALVE ASSEMBLY ................................................................... 24
KETTLE JACKET ASSEMBLY ......................................................... 25
OCTOBER 11, 2016 2 MT-25EO, MT-40EO & MT-60EO ELECTRIC KETTLES
GENERAL TROUBLESHOOTING
TROUBLE POSSIBLE CAUSE REMEDY
POWER ON/OFF SWITCH FAILS TO
LIGHT WITH SWITCH IN ON POSITION.
KETTLE NOT HOT ENOUGH TO BOIL
WATER.
LOW WATER LIGHT ON. Low water level in reservoir. Fill reservoir.
KETTLE HARD TO TILT. Bearing loose or lacking lubrication. Repair or replace as required.
WATER DOES NOT ENTER BOILER. Water main shut-off. Turn ON.
BOILER OVER FILLS WITH WATER. Lack of water level probe sensitivity due to
WATER ENTERS BOILER VERY SLOWLY. Dirty strainer screen in water ll valve. Clean or replace strainer screen.
AIRVENT LEAKING. Not closing. Replace.
Power to kettle off. Located external Shut-Off (circuit breaker)
for incoming power and place in ON position.
Low water level in kettle reservoir Fill reservoir.
Power ON/OFF light burned out Replace switch.
Faulty power ON/OFF switch Replace switch.
Faulty water level control Replace control (see water level control)
Faulty wiring. Inspect condition of wire & tightness of all
connectors. Correct as required.
Air in kettle reservoir. Replace steam trap as needed.
Faulty (weeping) safety relief valve. Replace valve.
Burned out heating elements. Replace as required (see heating element
replacement).
Pressure switch faulty. Recalibrate or replace as required (see ad-
justments).
Faulty wiring. Inspect and repair as required.
Defective water level control. Replace control as required.
Lime build-up on probes. Clean probes (see probe cleaning)
Power not reaching unit. Check main breaker.
Lack of water level probe sensitivity due to
lime build-up.
Defective water ll valve. Clean strainer.
Defective water switch (marked power
switch on control box).
Water pressure to low. Increase water pressure to 25-50 PSI.
lime build-up.
Water ll valve fails to close. Clean valve seat and strainer.
Defective water level board. Replace.
Water pressure to high. Check pressure. If above 50 PSI, decrease
Dirt or lime accumulation of water ll valve
seat.
Water pressure to low Increase pressure to 25-50 PSI.
Clean probe (see water level control maintenance and cleaning).
Check oil for continuity. Replace if defective.
Check continuity. Replace if defective.
Clean probe (see probe cleaning)
pressure.
Clean valve seat.
OCTOBER 11, 2016 3 MT-25EO, MT-40EO & MT-60EO ELECTRIC KETTLES
GENERAL TROUBLESHOOTING
TROUBLE POSSIBLE CAUSE REMEDY
BOILER FAILS TO BUILD UP PRESSURE
WHEN WATER LEVEL IS PROPER &
HEAT SWITCH IS TURNED ON.
BOILER FAILS TO REACH FULL OPERATING PRESSURE (OF APPROX. 15 PSI).
Contactors not pulling in. Check continuity of coil. If open replace
contactor.
Defective steam trap. Replace trap or clean.
Heating elements defective. Replace if continuity check through the cir-
cuitry of each element shows deciency
(see heating element replacement)
Pressure gauge reads inaccurately. Replace pressure gauge.
Operating pressure control and high limit
control switches out of adjustment.
Safety valve not seating properly. Clean or replace as required.
Contactor coils (1 or both) not energizing
and closing circuits to the heating elements.
Operating pressure control & high limit control switches b. Readjust or replace as required (see pressure switch adjustment
1. Check contactor. Replace either contactor coils or complete contactor as
required.
2. Measure amperage at terminal block.
Check to ensure that there is an even
draw on all 3 Phases. See wiring diagram for correct amperage draw. If uneven or '0' amp draw is found on 1 of
the 3 phases, check for blown fuse. If
fuse not blown, shut off power.
3. Remove wires from heating elements
& run continuity check. Replace as required.
CONTACTOR CHATTERS. Incorrect supply voltage. Check to see that voltage supply matches
with coil in connectors.
Dirty or worn contactor points. Clean or replace contactor.
Weak coil. Replace with correct voltage coil.
SAFETY VALVE BLOWS OFF PREMATURELY.
BOILER BUILDS UP TO PRESSURE,
THEN SHUTS DOWN & FAILS TO COME
BACK ON.
COLD WATER CONDENSER DOES NOT
FUNCTION.
CONTACTOR CHATTER. a..................................................................
Pressure set to high. Readjust pressure switch.
Pressure gauge reads incorrectly. Replace pressure gauge.
Lime or dirt on valve seat. Clean valve seat.
Weak spring in valve. Replace valve.
High limit switch set to low or operating
pressure control switch to high.
Main water line shut-off. Turn on.
Thermostat out of adjustment or defective. Readjust for proper operation or replace if
Loose t. Tighten coil as close to body of valve as
Coil not continuous. If open, replace.
Low voltage.
Readjust or replace as required (see pressure switch adjustment)
defective (see cold water condenser)
possible.
1. Check voltage condition. Check momentary voltage dip during starting.
Low voltage prevents magnet sealing.
2. Check coil voltage rating. Correct voltage condition as required.
Defective or incorrect coil. Replace coil. Rating of coil must match the
line voltage
OCTOBER 11, 2016 4 MT-25EO, MT-40EO & MT-60EO ELECTRIC KETTLES
PRESSURE CONTROL SWITCH ADJUSTMENT
A
B
If boiler fails to maintain steam pressure in operating
range, pressure control switch may require adjustment.
1. Start boiler and allow pressure to build up to operating level - 15 PSI (1kg/cm²).
2. Check boiler pressure gauge. If gauge indicates 12
to 14 PSI, pressure control switches are properly adjusted.
3. If boiler does not come on when pressure gauge
reads 7 PSI and does not go off when pressure gauge
reads 14 PSI, proceed as follows:
WARNING
Because power must be on to adjust pressure
switches, be sure to protect against electrical
shock.
a. Remove screw and lift front cover off control box.
b. Hand adjust operating pressure control switch
and high limit pressure control switch by turning adjusting nut (Knurled knob) clockwise to
raise and counter clockwise to lower actuation
point. Switch should be set so that boiler comes
on when boiler pressure gauge reads 12 PSI
and goes off when gauge reads 14 PSI. Switch
should be set so that boiler will shut off if pressure reaches 15 PSI.
WARNING
Because power must be on to adjust pressure
switches, be sure to protect against electrical
shock.
1. Check that the (2) different switches are actually
used.
2. Set high limit switch H15 all the way to maximum at
15 PSI.
3. Set operating control switch F15 ON at 10 PSI, OFF
at 12 PSI.
When unit is properly operating, switch F15 will shut boiler off at approximately 14 PSI and turn back on at approximately 11 PSI.
Also, switch H15 will cause low water light on boiler control box (under cabinet) to come on due to reaching high
pressure.
c. The actuation value (differential) is factory set
and cannot be changed.
d. Repeat steps, 1, 2, and 3. If 45 to 14 PSI boiler
pressure gauge reading is obtained during boiler
operation, adjustment is correct. If proper adjustment cannot be made consult Trouble-Shooting
Guide in this manual.
e. After making adjustments, replace cover on pres-
sure switch box and screw.
OCTOBER 11, 2016 5 MT-25EO, MT-40EO & MT-60EO ELECTRIC KETTLES
COLD WATER CONDENSER & LID COUNTERBALANCE ADJUSTMENT
COLD WATER CONDENSER ADJUSTMENT
The function of the cold water condenser is to keep
the temperature in the drain line from exceeding 150°F
(66°C). Solenoid valve (see Figure 4) controls the water
ow to the cold water condenser. The valve opens and
runs cold water through the drain until the temperature
drops below 150°F (66°C). The water ow may be regulated by adjusting thermostat dial.
The valve has a built-in water strainer which should be
removed and periodically cleaned.
LID COUNTERBALANCE ADJUSTMENT
The kettle lid is equipped with a torsion spring counterbalance device to assist in lid lifting and to prevent slam-
ming. The device is shown assembled in gure 5 (internal
cabinet, side view) and exploded in gure 0 (hinge and lid
assembly). If lid slams closed when handle is released,
spring tension should be increased. If lid lifts up or refuses to remain down on kettle, tension should be reduced.
To adjust spring tension, proceed as follows:
1. Lift cover to open position.
2. Pull down on piston assembly to release it from its
position. Rotate “T” bar clockwise to increase tension,
continue clockwise to reduce tension.
3. Operate lid several times. Repeat step 2 until desired
operation is obtained.
4. Hold hex head screw rmly in position and tighten
hex nut to lock adjustment.
OCTOBER 11, 2016 6 MT-25EO, MT-40EO & MT-60EO ELECTRIC KETTLES
HEATING ELEMENT REPLACEMENT
1
2 5 3
4
Check for defective heating elements as follows:
With the power off and disconnected, connect an ohmmeter to the two leads of each element loop at room
temperature. Resistance should be as follows:
VOLTS OHMS
208 10.8 +/- 5%
240 14.4 +/- 5%
*480 38.0 +/- 5%
*480 OHM rating Is based on 4000 w/277v.
If not, element is defective and must be replaced. Proceed as follows:
1. Shut down power to unit, boiler will drain.
2. Disconnect wires at contactor.
3. Remove nut (2) and gasket until element is freed.
4. Replace with new element.
ITEM PART NO. DESCRIPTION
1 08-6415 208V Element, 12 kW
1 08-6416 240V Element, 12 kW
1 08-6417 480V Element, 12 kW
2 91-8660 Element Gasket
3 98-3945 Nut
4 91-8756 Gasket Front Plate
5 08-6553 Secondary Low Water Cut Off
OCTOBER 11, 2016 7 MT-25EO, MT-40EO & MT-60EO ELECTRIC KETTLES
WATER CONTROL BOARD TESTING PROCEDURE
LED 1
LED 2
LED 3
RESET
LW2
GND
LW1
FW - HIGH
HTA NO
LO LITE (NC)
FW (NO)
L1
L2
This test procedure is to be used to determine if the control is working properly. It is not intended to determine why
the control may have failed.
If testing shows that the control is operating properly,
check all probe and solenoid wiring and the condition of
the electrodes in the steam chamber.
Contact the factory if the boiler still does not operate properly after completing the testing.
Tools Needed:
• Digital or Analog V-O-M meter.
• Alligator clip type test jumpers (2 sets min.).
Turn Off Power to Control:
• Use V-O-M to verify there is no power at terminals L
1 & L2.
• Use V-O-M to verify that there is no power at terminals ‘FW(NO)’, ‘LO LlTE(NC)’ & ‘HTR(NO)’. If there
is power at any of these terminals, you will need to
nd the source and turn it off.
Remove Wires from Probe and Relay Switch Terminals:
• DO NOT remove wires from L 1 & L2 terminals.
• Tag wires and remove from probe and relay contact
terminals including ‘GND’ terminal.
• Tag and remove wires from ‘RESET’ terminals.
• Connect jumper wire to both ’RESET’ terminals.
Turn Power On to Terminals L 1 & L2:
• ‘LED l’ should turn on.
• ‘LED 2’ should be off.
• ‘LED 3’ should be off.
• Use V-O-M to verify that there is power at ‘FW(NO)’
& ‘LO LlTE(NC)’ terminals and no power ‘HTR(NO)’
terminals
Test Feedwater Function:
• Connect jumper wire to ‘FW HIGH and ‘GND’ terminals.
• ‘LED l’ should turn off after a 10 second delay.
• Use V-O-M to verify that there is no power at the
‘FW (NO)’ terminal.
• Remove jumper from ‘FW HIGH’ and ‘GND’ terminals. . ‘LED l’ should turn on.
• Use V-O-M to verify that there is power at the
‘FW(NO)’ terminal.
OCTOBER 11, 2016 8 MT-25EO, MT-40EO & MT-60EO ELECTRIC KETTLES
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