SERVICE MANUAL
C24EO SERIES
ELECTRIC
COUNTERTOP
STEAMERS
MODEL ML
C24EO3 136006
C24EO5 136007
C24E05 SHOWN
This Manual is prepared for the use of trained Vulcan Service
Technicians and should not be used by those not properly qualified.
This manual is not intended to be all encompassing. If you have not
attended a Vulcan Service School for this product, you should read,
in its entirety, the repair procedure you wish to perform to
determine if you have the necessary tools, instruments and skills
required to perform the procedure. Procedures for which you do not
have the necessary tools, instruments and skills should be
performed by a trained Vulcan Service Technician.
The reproduction, transfer, sale or other use of this Manual, without
the express written consent of Vulcan, is prohibited.
This manual has been provided to you by ITW Food Equipment
Group LLC ("ITW FEG") without charge and remains the property
of ITW FEG, and by accepting this manual you agree that you will
return it to ITW FEG promptly upon its request for such return at
any time in the future.
For additional information on Vulcan-Hart or to locate an authorized parts and
service provider in your area, visit our website at www.vulcanequipment.com.
A product of VULCAN-HART BALTIMORE, MD 21222
F25386 (June 2010)
C24EO SERIES STEAMERS
TABLE OF CONTENTS
GENERAL ................................................................................3
Installation, Operation and Cleaning ........................................................3
Introduction ............................................................................3
Features ..........................................................................3
Steam Cooking.....................................................................3
Model Designations .................................................................3
Specifications ..........................................................................3
Water Requirements .................................................................3
Electric ........................................................................... 3
Tools.................................................................................4
REMOVAL AND REPLACEMENT OF PARTS ....................................................5
Covers and Panels ......................................................................5
Component Panel Components ............................................................ 5
Timer ................................................................................ 6
Hold Thermostat........................................................................ 6
High Limit Thermostat ................................................................... 7
Low Water Thermostat...................................................................7
Temperature Probe ..................................................................... 8
Heating Element Assembly ...............................................................8
Manual Drain Valve .....................................................................9
Door ................................................................................10
SERVICE PROCEDURES AND ADJUSTMENTS.................................................13
Door Latch Adjustment.................................................................. 13
Heating Element Test................................................................... 14
Temperature Control Calibration ..........................................................15
ELECTRICAL OPERATION.................................................................. 16
Component Function ...................................................................16
Component Location ...................................................................17
Sequence of Operation ..................................................................18
Schematic Diagram ....................................................................20
Wiring Diagrams - Heating Elements ......................................................21
TROUBLESHOOTING......................................................................24
© Vulcan 2010
F25386 (June 2010)
Page 2 of 24
C24EO SERIES STEAMERS - GENERAL
GENERAL
INSTALLATION, OPERATION
AND CLEANING
Refer to the Installation & Operation Manual for
specific instructions.
INTRODUCTION
Features
! Requires no water or drain line connections
(manual fill & manual drain).
! Cast aluminum element block for efficient heat
transfer and distribution.
! Field convertible to single phase or three phase
power depending on the supply available.
! 3.0 gallons maximum holding pan capacity.
Steam Cooking
The C24EO series steamer provides timed or
continuous mode cooking in a pressure-less
compartment. The small physical size of the steamer
offers an efficient way to produce many foods in
small batches. Pressure-less, convection steam
cooking will steam cook fresh foods or will steam
defrost and cook frozen foods providing the
maximum color, flavor and nutritional value with the
least expenditure of energy and labor. The pressureless cooking compartment allows the operator to
open and close the door, anytime during a cooking
cycle.
Model Designations
! C24EO3 - 3 pan capacity*
! C24EO5 - 5 pan capacity*
*based on 2.5 inch pan depth
SPECIFICATIONS
Water Requirements
A potable water supply does not guarantee that it's
suitable for steam generation. The water supply must
be within the following specifications or a local water
treatment specialist may need to be consulted. If a
water treatment system is installed, it must be
properly maintained.
! Hardness* - Less than 3 grains
! Silica - Less than 13 ppm
! Total Chloride - Less than 4 ppm
! Ph range of - 7.0 to 8.0
! Un-dissolved Solids - less then 5 microns
* 17.1ppm = 1 grain of hardness
Electric
AMPERAGE PER LINE
MODEL
C24EO3 8 22.2 19.2 - 38.5 33.3
C24EO5 12 33.3 28.9 14.4 57.7 50.0
NOTES:
TOTAL
KW
1. Amperage values in the table are
nominal. Tolerance is +5/-10%.
2. C24EO3 - Shipped for 208V 60-50 HZ 3
phase connection. Field convertible to
240V three phase or 208/240V single
phase. See wiring diagram AI2853.
3. C24EO5 - Shipped for 208V or 240V or
480V 60-50 HZ, 3 phase. 208V and 240V
models are field convertible to 1 phase.
See wiring diagram AI2852.
3 PHASE 1 PHASE
208V 240V 480V 208V 240V
Exterior Dimensions
! C24EO3 - 24" w x 33" d x 19.5" h
! C24EO5 - 24" w x 33" d x 26" h
F25386 (June 2010)Page 3 of 24
C24EO SERIES STEAMERS - GENERAL
TOOLS
Standard
! Standard set of hand tools
! Clear silicone sealant
! VOM with an AC current tester (any quality
VOM with a sensitivity of at least 20,000 ohms
per volt can be used)
! Temperature meter & thermocouple
Special
! Thermal Transfer Compound, Dow Corning 340
Part No. 819643-2 (13.5 oz. tube) or equivalent
for heating element assembly
! Thermal Transfer Compound, Dow Corning 340
Part No. 519504 (2 oz. tube) or equivalent for
thermostats
! Torque wrench (in.-lb.)
! Tile Trowel 3/16" x 5/32" V notch; Grainger
catalog stock number 5LG08 or equivalent for
coating heating element assembly with thermal
transfer compound
®
! Loctite
(McMaster-Carr Part No. 66415A21) or
equivalent fast drying, no residue cleaner.
! Loctite
! Loctite
! Loctite
door screws
ODC-Free Cleaner and Degreaser
®
7471™ Primer N™ Part No. 544434-2
®
271™ or equivalent
®
242™ Part No. 520228 for threads of
! RTV 109 for securing gasket to door
! Lubriplate 630AA for door handle sliding bracket
F25386 (June 2010)
Page 4 of 24
C24EO SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
REMOVAL AND REPLACEMENT OF PARTS
COVERS AND PANELS
Side Panels
1. Remove screws from bottom of panel.
4. Lift top cover off machine.
5. Reverse procedure to install.
Rear Panel
1. Remove screws securing rear panel.
2. Slide panel down to clear top cover.
3. Reverse procedure to install.
Top Cover
1. Remove SIDE PANELS.
2. Remove screws securing rear of top cover.
3. Remove nuts securing front of top cover.
2. Disconnect tube from steam vent pipe.
3. Remove rear panel.
4. Reverse procedure to install.
COMPONENT PANEL
COMPONENTS
1. Remove right side panel as outlined under
COVERS AND PANELS.
F25386 (June 2010)Page 5 of 24
C24EO SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
2. Disconnect lead wires to component being
replaced.
3. Remove component.
4. Reverse procedure to install replacement
component and check steamer for proper
operation.
NOTE: If replacing temperature control, see
TEMPERATURE CONTROL CALIBRATION in
SERVICE PROCEDURES AND ADJUSTMENTS.
4. Remove rotary shaft seal from timer shaft and
remove timer.
5. Reverse procedure to install and check steamer
for proper operation.
HOLD THERMOSTAT
TIMER
1. Remove right SIDE PANEL.
2. Disconnect lead wires to timer.
1. Remove right SIDE PANEL.
2. Remove lead wires and mounting nuts.
3. Remove hold thermostat.
4. Apply a small amount of thermal transfer
compound to the mating surface (disk side) of
the replacement thermostat.
A. Spread the compound completely and
evenly over the surface of the thermostat.
5. Reverse procedure to install and check steamer
3. Remove timer knob.
F25386 (June 2010) Page 6 of 24
for proper operation.
C24EO SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
HIGH LIMIT THERMOSTAT
Do not sharply bend and kink, or clamp
down on the capillary tube or damage may occur.
1. Remove right SIDE PANEL.
2. Disconnect lead wires from high limit.
6. Remove high limit thermostat.
7. Reverse procedure to install and check steamer
for proper operation.
A. Apply a small amount of thermal transfer
compound between capillary bulb and
heating element assembly.
NOTE: Do not clamp bulb with excessive force.
3. Remove thermostat from mounting bracket.
4. Remove screw and heat shield to access
capillary bulb.
LOW WATER THERMOSTAT
1. Remove right SIDE PANEL and REAR PANEL.
2. Disconnect lead wires.
5. Loosen screws securing capillary bulb.
3. Remove low water thermostat.
4. Reverse procedure to install and check steamer
for proper operation.
A. Apply small amount of thermal transfer
compound to tip of thermostat.
B. Apply Loctite 242 to threads of thermostat.
F25386 (June 2010)Page 7 of 24
C24EO SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
C. Install thermostat hand tight. Do not over
tighten.
TEMPERATURE PROBE
1. Remove right SIDE PANEL and REAR PANEL.
2. Disconnect probe leads from the temperature
control.
1. Remove right SIDE PANEL.
2. Remove screw and heat shield.
3. Remove bolts.
NOTE: Support heating element assembly while
removing last bolt.
3. Remove temperature probe from steam vent
pipe.
4. Reverse procedure to install replacement probe
and check steamer for proper operation.
5. Adjust temperature control as outlined under
TEMPERATURE CONTROL CALIBRATION in
SERVICE PROCEDURES AND
ADJUSTMENTS.
HEATING ELEMENT ASSEMBLY
Removal
The heating element assembly contains elements
molded into a cast aluminum block. The block is
mounted on the underside of cooking compartment.
Heating element assembly sits on springs which
compress to hold assembly tight to bottom surface of
steam chamber but allow for thermal expansion and
contraction.
4. Disconnect heating element leads from 1CON
and 2CON, noting their locations.
F25386 (June 2010) Page 8 of 24
C24EO SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
5. Partially remove heating element assembly by
pulling assembly towards you.
6. Remove high limit thermostat bulb and bracket.
7. Remove heating element assembly.
Installation
NOTE: When replacing element assembly for 3 pan
unit with 240V supply, disconnect and insulate
element leads with orange, green, and red markers
(three 664W elements not used).
MANUAL DRAIN VALVE
1. Remove right SIDE PANEL and REAR PANEL.
2. Remove pin and washer to disconnect the
handle linkage from linkage bracket.
1. Completely and evenly coat heating element
assembly with thermal transfer compound using
notched trowel. (Use one 13.5 oz. tube of
thermal transfer compound)
2. Partially install heating element assembly, then
mount high limit thermostat bulb and bracket to
assembly.
A. Apply thermal transfer compound between
high limit bulb and heating element
assembly.
3. Install heating element assembly. Push element
assembly towards front of machine.
3. Remove nut and linkage bracket.
4. Remove drain valve.
5. Reassemble parts removed in reverse order of
removal.
A. Apply pipe thread sealant to plumbing
threads before assembly.
6. Check steamer for leaks and proper operation.
4. Connect lead wires to 1CON and 2CON in noted
positions.
5. Check steamer for proper operation.
F25386 (June 2010)Page 9 of 24
C24EO SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
DOOR
Removal
1. Close door.
2. Remove left SIDE PANEL.
3. Remove nuts from upper hinge located inside
front panel.
3. Remove gasket plate.
4. Remove gasket from inner door panel.
5. Remove RTV from bottom part of inner door
panel. Apply new RTV 109 to bottom of door
where shown when assembling gasket to door.
6. Place a small amount of RTV109 into the inner
door panel gasket screw holes before assembly.
7. Position the new gasket on gasket plate and
reverse procedure to install.
Handle Removal
4. Open door slightly, and while holding door, pull
upper hinge away from front panel.
5. Pull upper hinge out of upper door hinge
bushing.
6. Lift door assembly up and off lower door hinge.
7. Reinstall parts removed in reverse order of
removal.
8. Check door for fit and proper sealing of gasket.
Gasket
1. Open door.
2. Remove the shoulder screws and pan pusher
bracket from gasket plate.
1. Open door.
2. Remove screws from top and bottom of door
assembly.
3. Pull outer door housing away from inner door
panel starting at the hinge side of door to
separate the door halves.
NOTE: The smaller radius of the step spacers fit into
the slots of the outer door housing and is used to
provide clearance for handle operation.
4. Remove lock nuts and stepped spacers from
F25386 (June 2010) Page 10 of 24
threaded studs of door handle.
C24EO SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
Handle Installation
1. Apply Lubriplate 630AA around slots of outer
door housing where step spacers contact
housing.
2. Install door handle into outer door housing such
that hinge side of door housing is to the left and
arrow on handle is pointed upward.
3. Install step spacer with smaller radius toward
handle and door housing. Smaller radius is a slip
fit with outer door housing slot.
8. Apply Loctite 7471 Primer N and Loctite 242 to
threads of screws before assembling.
9. Install screws to secure door halves together.
10. Check opening and closing operation of door.
Latch Assembly Removal and Disassembly
1. Separate outer door housing assembly from
inner door panel as outlined under DOOR
HANDLE REMOVAL.
2. Remove screws securing latch assembly to inner
door panel and remove latch mechanism.
4. Install lock nuts and tighten until no gap exists
between handle, step spacer and lock nut. Do
not over-tighten lock nuts.
5. Close inner door panel so that latch mechanism
engages striker on front panel.
6. Install outer door housing onto inner door panel.
7. Align the top and bottom screw holes of outer
door housing with inner door panel.
3. Remove E-clip from latch assembly pins and pull
pins from latch mechanism.
4. Remove retaining pin from spring pin.
5. Separate sliding bracket from stationary bracket.
F25386 (June 2010)Page 11 of 24
C24EO SERIES STEAMERS - REMOVAL AND REPLACEMENT OF PARTS
Assembly
1. Apply Lubriplate 630AA to sides of sliding
bracket.
2. Insert spring pin into bottom of sliding bracket.
A. Place spring over spring pin.
3. Assemble sliding bracket into stationary bracket.
4. While holding head of spring pin against bottom
of sliding bracket, insert spring pin into keeper
hole in bottom of stationary bracket.
3. Check opening and closing operation of door.
4. Check steamer for proper operation and leaks
around door seal.
Hinge Bearings
1. Close door.
2. Remove left SIDE PANEL.
3. Remove nuts from upper hinge located inside
front panel.
4. Open door slightly, and while holding door, pull
upper hinge away from front panel.
A. Secure spring pin in place with retaining pin.
NOTE: Install pins such that heads of pins will be
facing inward toward hinge side of inner door panel
when latch assembly is installed.
5. Install pins to assemble stationary and sliding
brackets together.
A. Secure pins into position with E-clip.
Installation
1. Install latch assembly onto inner door panel with
spring pin toward bottom of door panel.
A. Apply Loctite 271 to threads of screws
before assembly and secure latch assembly
to inner door panel.
5. Pull upper hinge out of upper door hinge bearing.
6. Lift door assembly up and off lower door hinge.
7. Pry hinge bearing out from door assembly.
8. Remove outer door housing.
Do not drive bearing into place. The inner
door panel could be damaged. Press bearing into
position.
NOTE: When replacing door hinge bearings, replace
both hinge bearings.
9. Position replacement hinge bearing over hinge
opening in door assembly.
2. Install outer door housing assembly as outlined
in DOOR HANDLE INSTALLATION.
F25386 (June 2010)
A. Press hinge bearing fully into door assembly
using a C-clamp or equivalent.
10. Reassemble parts removed in reverse order.
11. Check door for fit and proper door gasket
sealing.
Page 12 of 24
C24EO SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
SERVICE PROCEDURES AND ADJUSTMENTS
DOOR LATCH ADJUSTMENT
Opening a Jammed Door
Should the steamer door jam and cannot be
opened, DO NOT FORCE OR PRY the door as
damage will occur.
1. Lift up on bottom of door at the handle end to
disengage latch.
A. If door does not open, remove right SIDE
PANEL.
B. Locate the striker that catches on door latch
near steam chamber on front panel.
D. Open door.
2. Remove striker.
3. Remove any burrs on striker that may cause
latch to stick.
4. Apply Loctite 271 to threads of striker.
5. Reinstall striker with slotted side up. Snug striker
nut. Perform Adjustment, so door will not jam.
Adjustment
1. Reinstall striker with slot pointing upward and
hand tighten nut only.
2. Close door to center striker in front panel
mounting hole.
3. Open door and check striker slot for horizontal
alignment. The slot on striker must be kept
horizontal in order for door latch to catch
properly and latch.
4. Once proper slot alignment has been set, hold
striker close to its base then tighten the striker
nut. Be careful not to damage striker slot when
tightening or door may not latch properly.
NOTE: Do not over-tighten nut. If over-tightened,
striker may turn and change alignment.
C. Remove nut from striker and this should
release it from the panel.
NOTE: If door does not open easily, add shims
between striker and cabinet front. When adding
shims make certain that door gasket seals properly
and steamer does not leak. Remove shims as
necessary until leaking stops.
F25386 (June 2010)Page 13 of 24
C24EO SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
HEATING ELEMENT TEST
The heating element assembly contains elements
molded into a cast aluminum block. 3 pan units have
6 elements and 5 pan units have 3 elements. See
wiring diagrams.
1. Turn cooking mode switch to constant.
2. Measure voltage at heating element terminals on
contactors and verify it against data plate
voltage.
NOTE: For 480V units, element voltage is 277V.
A. If voltage is incorrect, find the source of the
problem.
B. If voltage is correct, check current draw
(amps) through the heating element lead
wires.
NOTE: This method is preferred over a
resistance check when a clamp on type amp
meter is available.
1) If current draw is correct then heating
element is functioning properly. See
table below for proper values.
2) If current draw is not correct, turn
cooking mode switch to OFF and
disconnect the electrical supply.
3. Check for proper operation.
MODEL VOLTS
208 2003 9.6 21.6
C24EO3
C24EO5
NOTES:
208 664 3.2 65.2
240 2667 11.1 21.6
208 4000 19.2 10.8
240 4000 16.7 14.4
480 4000 14.4 19.2
1. Values in the table are nominal. Tolerance
is +5/-10%.
2. 3 pan 208V units use three 2003W
elements and three 664W elements.
3. 3 pan 208/240V units share the same
element assembly block. 240V units use
only the three 2003W-marked elements
(2667W actual).
4. Resistance values (ohms) are @ 77
room temperature.
WATTS
PER
ELEMENT
AMPS PER
ELEMENT
LEAD
OHMS PER
ELEMENT
"
F
a. Replace heating element assembly
then proceed to step 3.
C. If unable to check current draw, a resistance
check may indicate a malfunctioning
element.
1) Turn the cooking mode switch to OFF
and disconnect the electrical supply.
2) Remove the lead wires from the heating
element and check resistance (ohms).
See table below for proper values.
F25386 (June 2010) Page 14 of 24
C24EO SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS
TEMPERATURE CONTROL
CALIBRATION
To set the temperature control for optimum steamer
operation, the elevation above sea level for the
service location must
steamer was preset at the factory to sea level.
The elevation is used in conjunction with the
elevation table below, to determine the correct set
point temperature for the control.
NOTE: If the set point temperature is too high, the
excess boiling action will cause water droplets to exit
the steam vent pipe, and cause high water usage.
1. Remove right SIDE PANEL as outlined in
REMOVAL AND REPLACEMENT OF PARTS.
2. Place a thermocouple approximately one inch
down in the center of steam vent pipe.
3. Turn steamer on by selecting constant mode.
4. Allow steamer temperature to stabilize by
completing two heating cycles.
5. Record the temperature reading when cook light
goes out.
first be determined. The
1) Turn the temperature control dial
clockwise
counterclockwise
temperature.
NOTE: During temperature control adjustment,
display will blink on/off. When display reverts to a
steady image, that displayed temperature set point
has been "locked in" to memory.
to increase temperature or
to decrease
6. Using the elevation table, compare the recorded
temperature to the temperature listed for the
specific elevation.
NOTE: Use temperature scale on control dial plate
for reference only. The scale represents dial turns in
1°F increments, not the actual temperature. When
calibrating, use the recorded temperature taken from
thermocouple.
ELEVATION (FT) TEMPERATURE (EF)
Sea Level 210
1,000 208
2,000 206
3,000 204
4,000 202
5,000 200
6,000 198
7,000 196
8,000 195
9,000 or above 194
A. If the set point temperature of the control is
correct, no adjustment is necessary.
B. If the set point temperature of the control is
not correct, adjust the temperature control.
F25386 (June 2010)Page 15 of 24
C24EO SERIES STEAMER - ELECTRICAL OPERATION
ELECTRICAL OPERATION
COMPONENT FUNCTION
Buzzer ................................ Creates audible signal when timed cook cycle is complete and
when a low water condition exists.
Limiting Contactor (1CON) ............... Supplies line voltage to heating element assembly. Energized
whenever Power Switch (1S) is on and High Limit Thermostat
(1TAS) and Low Water Thermostat (2TAS) are closed.
Regulating Contactor (2CON) ............. Supplies line voltage to heating element assembly. Energized
whenever Hold Thermostat (3TAS) is closed or the temperature
controller calls for heat.
Heating Element ........................ Located below water reservoir. Heats water to produce steam.
Fuses (1FU & 2FU) ...................... Protect control circuitry from over-currents.
Low Water Light (1LT) ................... Amber (AM) colored light. Lit when Low Water Thermostat
(2TAS) senses water level is too low inside steamer.
On Light (2LT) ......................... Amber (AM) colored light. Lit when Power Switch (1S) is on.
Cook Light (3LT) ....................... Red (RD) colored light. Lit when High Limit (1TAS) and Low
Water (2TAS) thermostats are closed, door is closed and timer
is set.
Relay (K1) ............................. Controls Regulating Contactor (2CON) based on input from
Hold Thermostat (3TAS) and Temperature Controller. Does not
allow Timer Motor to run while Hold Thermostat (3TAS) is
closed.
Relay (K2) ............................. Latches Power Switch (1S) circuit. Turns on Low Water Light
(1LT) and Buzzer when steamer is low on water.
Relay (K3) ............................. Controlled by Power Switch (1S). Keeps Buzzer from sounding
and Low Water Light (1LT) off when switch is in off position.
Power Switch (1S) ...................... Rocker switch that turns steamer OFF and ON (momentary on).
Switch also resets Low Water Light (1LT) and Buzzer.
Door Switch (1SW) ..................... Removes power from a portion of the steamer control circuit
when door is opened.
High Limit Thermostat (1TAS)............. Protects steamer by removing control circuit power if the heating
element assembly temperature goes above 495EF.
Low Water Thermostat (2TAS) ............ Monitors presence of water inside steamer.
Hold Thermostat (3TAS) ................. Controls temperature of cavity for pre-heat/hold mode (opens at
175E F). Disables timer countdown if cavity temperature is too
low.
Timer Motor............................ Counts cook time of product when time is dialed. Energizes
buzzer and de-energizes temperature controller when time
expires.
Temperature Control .................... Monitors temperature probe and cycles power to regulating
contactor (2CON) for steam generation.
Temperature Probe ..................... Senses cooking compartment temperature at steam vent and
sends a corresponding DC voltage back to the temperature
control (J-type thermocouple).
Transformer (1T) ....................... Steps down line voltage to 120VAC control circuit voltage.
F25386 (June 2010)
Page 16 of 24
C24EO SERIES STEAMER - ELECTRICAL OPERATION
COMPONENT LOCATION
CONTROL PANEL COMPONENTS
FRONT PANEL COMPONENTS
Page 17 of 24
F25386 (June 2010)
C24EO SERIES STEAMER - ELECTRICAL OPERATION
SEQUENCE OF OPERATION
Schematic diagram AI2851 will be used to explain
the electrical sequence of operation.
Timed Cooking Mode
1. Conditions.
A. Steamer connected to correct voltage and
is properly grounded.
B. Power switch (1S) off.
1) Relay K3 energized. K3 N.C.
contacts open.
C. High limit thermostat closed.
D. Hold thermostat closed.
E. Low water thermostat closed.
F. Temperature control is setup properly and
is ready to use.
G. Door closed (door switch closed).
H. Timer off.
I. Cooking compartment filled to the water
level mark and below hold temperature of
175°F (+/- 5°F).
J. Drain valve is closed (drain lever pushed
in).
2. Press momentary start switch (1S).
A. Limiting contactor (1CON) coil energized
thru high limit thermostat (1TAS).
1) Line voltage is supplied to one side of
heating elements.
B. Relay K2 coil energized thru low water
thermostat (2TAS).
1) K2-1 N.O. contacts close.
a. Power switch circuit is latched.
2) K2-2 N.C. contacts open.
a. Low water light (1LT) and buzzer
are de-energized.
C. ON indicator light (2LT, amber) comes on.
D. Relay K1 coil energized thru door switch
and hold thermostat (3TAS).
1) K1-3 N.O. contacts close and
regulating contactor (2CON) coil is
energized.
a. Line voltage is supplied to other
side of heating elements.
Elements heat.
2) K1-2 N.C. contacts open.
3) K1-1 N.C. contacts open (prevents
timer from being energized during preheat).
3. Steamer reaches 175°F.
A. Hold thermostat opens and relay K1 coil is
de-energized.
1) K1-3 N.O. contacts close and remove
line voltage to heating element
assembly.
2) K1-1 and K1-2 N.C. contacts return to
close condition.
NOTE: Steamer will maintain hold temperature
until a cook time is dialed on timer, door is
opened, or power switch is turned off.
4. Set cook timer to desired time.
NOTE: Timer motor will not run when hold
thermostat (3TAS) is below 175°F.
A. Timer contacts close, timer motor is
energized and timing down begins.
NOTE: Additional time can be set or the cook
timer can be turned off throughout the cooking
cycle. If turned to off, steamer reverts to hold
temperature.
B. Cook light (3LT, red) comes on.
C. Temperature controller energized and
evaluates input from thermocouple.
1) If temperature is below set point,
temperature controller internal N.O.
contacts close and energize
regulating contactor (2CON) coil thru
K1-2 N.C. contacts.
a. Line voltage is supplied to other
side of heating elements.
Elements heat.
5. Temperature reaches set point and the
temperature control’s internal N.O. contacts
open.
A. Regulating contactor (2CON) coil de-
energized and power is removed from
heating elements.
6. Steamer cycles on the temperature control until
cook time expires.
7. Time expires on cook timer.
A. Timer contacts 11 & 13 open, timer motor
is de-energized and timing stops.
B. Timer contacts 11 & 14 close.
1) Buzzer energized thru K2 N.O.
contacts and sounds.
NOTE: The buzzer continues to sound until
timer dial is set to off position or additional
time is set.
C. Timer contacts 21 & 23 open, cook light
(3LT, red) goes out and temperature
controller is de-energized.
F25386 (June 2010)
Page 18 of 24
C24EO SERIES STEAMER - ELECTRICAL OPERATION
8. Turn cook timer off.
A. Timer contacts 11 & 14 open, buzzer is de-
energized.
B. Steamer reverts to hold temperature and
continues to cycle until a cook time is
dialed on timer, power switch is turned to
off, or the door is opened.
NOTE: If water level becomes low during
cycling, low water thermostat (2TAS) will open
and low water light (1LT, amber) will come on
and buzzer will sound. Timer and heating circuit
will be de-energized until water level is
replenished and thermostat closes.
Constant Cooking Mode
1. Conditions.
A. Steamer connected to correct voltage and
is properly grounded.
B. Power switch (1S) off.
1) Relay K3 energized. K3 N.C.
contacts open.
C. High limit thermostat closed.
D. Hold thermostat closed.
E. Low water thermostat closed.
F. Temperature control is setup properly and
is ready to use.
G. Door closed (door switch closed).
H. Timer off.
I. Cooking compartment filled to the water
level mark and below hold temperature of
175°F (+/- 5°F).
J. Drain valve is closed (drain lever pushed
in).
2. Press momentary start switch (1S).
A. Limiting contactor (1CON) coil energized
thru high limit thermostat (1TAS).
1) Line voltage is supplied to one side of
heating elements.
B. Relay K2 coil energized thru low water
thermostat (2TAS).
1) K2 N.O. contacts close.
a. Power switch circuit is latched.
2) K2 N.C. contacts open.
a. Low water light (1LT) and buzzer
are de-energized.
C. ON indicator light (2LT, amber) comes on.
1) K1 N.O. contacts close and regulating
contactor (2CON) coil is energized.
a. Line voltage is supplied to other
side of heating elements.
Elements heat.
2) K1 N.C. contacts open.
3. Steamer reaches 175°F.
A. Hold thermostat opens and relay K1 coil is
de-energized.
B. K1 N.C. contacts close and N.O. contacts
open.
NOTE: Steamer will maintain hold temperature
until a cook time is dialed on timer, door is
opened, or power switch is turned off.
4. Set cook timer to constant.
A. Timer contacts 21 & 23 close, cook light
(3LT, red) comes on.
B. Temperature controller energized and
evaluates input from thermocouple.
1) If temperature is below set point,
temperature controller internal N.O.
contacts close and energize
regulating contactor (2CON) coil thru
K1 N.C. contacts.
a. Line voltage is supplied to other
side of heating elements.
Elements heat.
5. Temperature reaches set point and the
temperature control’s internal N.O. contacts
open.
A. Regulating contactor (2CON) coil de-
energized and power is removed from
heating elements.
6. Steamer cycles on the temperature control until
cook timer turned off.
7. Turn cook timer off.
A. Timer contacts 21 & 23 open, cook light
(3LT, red) goes out and temperature
controller is de-energized.
B. Steamer reverts to hold temperature and
continues to cycle until a cook time is
dialed on timer, power switch is turned to
off, or the door is opened.
NOTE: If water level becomes low during
cycling, low water thermostat (2TAS) will open
and low water light (1LT, amber) will come on
and buzzer will sound.
D. Relay K1 coil energized thru door switch
and hold thermostat (3TAS).
Page 19 of 24
F25386 (June 2010)
C24EO SERIES STEAMER - ELECTRICAL OPERATION
SCHEMATIC DIAGRAM
F25386 (June 2010) Page 20 of 24
C24EO SERIES STEAMER - ELECTRICAL OPERATION
WIRING DIAGRAMS - HEATING
ELEMENTS
C24EO3 - 208V/240V
F25386 (June 2010)Page 21 of 24
C24EO5 - 208V/240V
C24EO SERIES STEAMER - ELECTRICAL OPERATION
F25386 (June 2010) Page 22 of 24
C24EO5 - 480V
C24EO SERIES STEAMER - ELECTRICAL OPERATION
F25386 (June 2010)Page 23 of 24
C24EO SERIES STEAMER - TROUBLESHOOTING
TROUBLESHOOTING
SYMPTOM POSSIBLE CAUSES
Compartment leaks water around door. 1. Steamer not level.
2. Steamer overfilled.
Steam leaks around door. 1. Worn gasket.
2. Damaged gasket.
3. Steam vent pipe blocked.
4. Door not adjusted.
Steamer will not heat (cook light off, low
water light off).
Steamer will not heat (cook light on, low
water light off).
Timer motor does not run. 1. Door open or door switch malfunction.
Door not closing properly. 1. Door latch assembly.
Door won’t open. 1. Latch inoperative.
Buzzer not operating. 1. Timer malfunction.
Water spraying out of steam vent pipe
during a cook cycle.
High water usage. 1. Temperature control set point too high.
Excessive or inconsistent cook times. 1. Door left open between loads.
1. Line voltage incorrect or transformer malfunction.
2. Control circuit fuse(s) open.
3. High limit thermostat open.
4. Door open or door switch malfunction.
5. Power switch off or inoperative.
6. Relay K3 malfunction.
7. Timer malfunction or timer off (timed mode only).
1. Line voltage incorrect.
2. Heating element malfunction.
3. Regulating contactor malfunction.
4. Relay K1 malfunction.
5. Temperature probe malfunction.
6. Temperature controller malfunction.
2. High limit thermostat open.
3. Low water thermostat open.
4. Timer inoperative.
2. Striker adjustment.
2. Buzzer malfunction.
1. Temperature control set point too high.
2. Temperature probe malfunction.
3. Temperature control malfunction.
2. Temperature probe malfunction.
3. Temperature control malfunction.
4. Steamer operating in constant mode.
2. Temperature control set point too low.
3. Heating element malfunction.
F25386 (June 2010) Printed in U.S.A.
Loading...