Vulcan-Hart | C24EA10 ML-136059 | Service manual | Vulcan-Hart C24EA10 ML-136059 Service manual

Vulcan-Hart C24EA10 ML-136059 Service manual
SERVICE MANUAL
C24EA SERIES
ELECTRIC CONVECTION
STEAMERS
C24EA6
C24EA10
ML-136058
ML-136059
C24EA6 SHOWN
- NOTICE This Manual is prepared for the use of trained Vulcan Service
Technicians and should not be used by those not properly
qualified. If you have attended a Vulcan Service School for this
product, you may be qualified to perform all the procedures
described in this manual.
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.
Reproduction or other use of this Manual, without the express
written consent of Vulcan, is prohibited.
For additional information on Vulcan-Hart Company or to locate an authorized
parts and service provider in your area, visit our website at www.vulcanhart.com
A product of VULCAN-HART
LOUISVILLE, KY 40201-0696
F35453 (July 2008)
MODEL C24EA
TABLE OF CONTENTS
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
COVERS AND PANELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
DOOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
THERMOSTAT AND HIGH LIMITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heat Exchanger High Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steam Generator High Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Condensate Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12
12
12
13
TIMERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
HEATING ELEMENTS AND CONTACTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
HEAT EXCHANGER ELEMENTS AND RELAYS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
WATER LEVEL CONTROL COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Level Control - Low Level Cut-Off and Differential Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Level Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Level Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filtered and Non-Filtered Dual Water Solenoid Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Motorized Drain Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21
21
22
22
23
24
SWITCHES, SOLENOIDS, RELAYS AND BUZZER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power and Delime Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Door Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Switch (1PAS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Switch (2PAS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vacuum Relief Solenoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compartment Steam Solenoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Time Delay Relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Buzzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26
26
26
27
29
29
30
30
31
CONTROL BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Layout and LED Legend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steam Generator Operational Status (LED Indicators) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deliming Cycle Status (LED Indicators) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
33
34
38
HEAT EXCHANGER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Motorized Delime Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
STEAM GENERATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
ELECTRICAL OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Smart Cycle Power Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Schematic Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
46
49
52
52
58
62
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
©VULCAN 2008
F35453 (July 2008)
Page 2 of 68
MODEL C24EA - GENERAL
GENERAL
INTRODUCTION
This manual is applicable to the models and ML
numbers listed on the cover page. Procedures apply
to all models unless specified otherwise.
Steam Cooking
Convection steamers offer an efficient way to
produce many foods in either small portions or larger
batches. 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 atmospheric steaming compartment
allows the operator to open and close the door
anytime during a cooking cycle. The generator
heating elements will shut off when the door is
opened then re-start when the door is closed.
MODELS COVERED
SPECIFICATIONS
All C24EA steamers, with exception of 480V
steamers, are shipped pre-wired for 208/60/3
operation. Steamer heating element wiring change is
required if connecting to 208/60/1, 240/60/1 or
240/60/3 electrical service.
ELECTRICAL SPECIFICATIONS
Volts
Phase Total
KW
C24EA10
Amps
Total
KW
Amps
208
1
16.9
81
25.6
121
240
1
19.0
79
25.6
110
208
3
16.9
48
25.2
240
3
19.0
51
480
3
17.2
21
Water Conditioning
It is recommended that a local water treatment
specialist be consulted before the installation of any
steam generating equipment.
Model Designations (based on 2.5 inch pan
depth)
C24EA6 - Six pan (3 pans per compartment)
C24EA10 - Ten pan (5 pans per compartment)
C24EA6
WATER SUPPLY REQUIREMENTS
Supply pressure should be
20-60 psig
In line strainer for supply line
(Supplied)
Total dissolved solids (TDS)*
less than 60 ppm
Total alkalinity
less than 20 ppm
Silica
less than 13 ppm
Total Chloride
less than 4.0 ppm
PH factor
6.5 to 8
Undissolved Solids
less than 5 microns
*17.1 ppm = 1 grain of hardness
Water hardness below 4 grains/gal requires water
treatment to reduce potential corrosion. Hardness
above 6 grains/gal should be treated by water
conditioner, water softener or in-line treatment.
Furnishing the steam generator with properly
conditioned water to reduce scale formation is
important. Scale formation will reduce steam output,
cause premature component failure and shorten
equipment life. Most water supplies contain scale
producing minerals such as calcium and magnesium.
As steam is generated, the minerals remain and
dissolve into the remaining water. As the
concentration of these minerals increases past a
certain point, they precipitate from the water and
coat the inside of the steam generator, heating
elements, thermostat bulbs and water level probes.
Because of the high temperature of these surfaces,
the precipitated minerals bake onto them and
become very difficult to remove.
This phenomenon causes several problems:
1.
Reduces the heat transfer efficiency of heating
elements.
72
2.
Causes premature failure of heating elements.
25.6
67
3.
Water level probes will give false readings.
25.6
32
4.
Temperature sensing bulbs will sense
temperature incorrectly.
NOTES: 1. Voltage values are @ 60HZ.
2. Heating elements on three phase
machines are not wired as a balanced
load. The amps listed are the
maximum on any leg.
3. Total KW and amps include heat
exchanger elements.
These problems are common to any manufacturer's
steamer regardless of design, but they can all be
prevented by furnishing the steam generator with
properly conditioned water. Vulcan recommends the
water contain less than 60ppm of total dissolved
solids (TDS) and have a PH factor between 6.5 to 8.
Page 3 of 68
F35453 (July 2008)
MODEL C24EA - GENERAL
Other chemical properties in water supplies can also
affect good steam generation and vary from within
each state and locality.
TOOLS
•
Standard set of hand tools.
The water level probes in the steam generator use
ions in the water to detect the water level. Do not use
fully demineralized or de-ionized water since it is
non-conductive and the water level can not be
detected.
•
VOM with A/C current tester (any quality VOM
with a sensitivity of at least 20K ohms per volt
can be used).
•
Anti Static Kit, Part No. TL - 84919.
NOTE: The use of strainers, or filters will not remove
minerals from the water.
Special
Steamers that operate over a long period of time
without the benefit of properly conditioned water, and
have developed a heavy scale build up, should be
cleaned before connecting to a conditioned water
supply.
•
Torque Wrench - Capable of measuring
70 in-lbs.
•
Aluminum Foil Tape - (McMaster-Carr Part No.
7631A21) or equivalent.
•
Single use Constant Tension Band Clamps for
the specific hose size being used. Refer to parts
catalog for part number.
•
Pressure Gauge Assembly
REFERENCE MATERIAL
For replacement parts, refer to Catalog of
Replacement Parts F35454.
•
Low Pressure Gauge - 0 to 5 psi.
recommended (Grainger Part No. 2C641).
•
Water Hose Coupling - swivel type
(Grainger Part No. 4KG87).
LUBRICATION
•
Reducer Bushing (Grainger Part No.
6MN61).
Component
Lubrication Type
All NPT Fittings Pipe Thread Sealant, Loctite 565
Door Handle
Lubriplate 630AA
Sliding Bracket
•
Pipe thread sealant (as required).
For operation, cleaning and maintenance
instructions, refer to Installation and Operation
Manual F35430.
F35453 (July 2008)
Page 4 of 68
MODEL C24EA - COVERS AND PANELS
COVERS AND PANELS
FRONT BASE PANEL
1.
RIGHT AND LEFT SIDE BASE
PANELS
Remove screws from the bottom of panel.
NOTE: Removal of left side panel is identical to the
procedure for the right side panel.
2.
Pull bottom of panel out and slide down to clear
tabletop cover.
3.
Reverse procedure to install.
1.
Remove FRONT BASE PANEL.
2.
Remove screws from the bottom of panel.
3.
Pull bottom of panel out and slide down to clear
tabletop cover.
4.
Reverse procedure to install.
Page 5 of 68
F35453 (July 2008)
MODEL C24EA - COVERS AND PANELS
REAR BASE PANEL
COOKING COMPARTMENT
RIGHT AND LEFT SIDE PANELS
1.
Remove electrical power connection to
machine.
2.
Turn off water supply and disconnect plumbing
to machine.
3.
Remove screws securing water valves to panel.
4.
Remove screws from the bottom of panel.
5.
Pull bottom of panel out and slide down to clear
tabletop cover.
6.
Reverse procedure to install.
F35453 (July 2008)
NOTE: Removal of left side panel is identical to the
procedure for the right side panel.
1.
Remove screws from the bottom of panel.
2.
Pull bottom of panel out and slide down to clear
top cover.
3.
Reverse procedure to install.
Page 6 of 68
MODEL C24EA - DOOR
DOOR
REMOVAL
GASKET
1.
Close door.
1.
Open door.
2.
Remove COOKING COMPARTMENT LEFT
SIDE PANEL as outlined under COVERS AND
PANELS.
2.
Remove the shoulder screws and pan pusher
bracket from gasket plate.
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 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.
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.
Reassemble parts removed in reverse order.
8.
Check door for fit and proper sealing of gasket.
Page 7 of 68
F35453 (July 2008)
MODEL C24EA - DOOR
DOOR HANDLE
Removal
1.
Open door.
2.
Remove screws from top and bottom of door
assembly.
3.
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.
8.
Install screws to secure door halves together.
Apply Loctite 242 to threads of screws before
assembly.
9.
Check opening and closing operation of door.
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
threaded studs of door 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.
F35453 (July 2008)
Page 8 of 68
MODEL C24EA - DOOR
Assembly
LATCH ASSEMBLY
1.
Apply Lubriplate 630AA to sides of sliding
bracket.
Separate outer door housing assembly from
inner door panel as outlined under DOOR
HANDLE.
2.
Insert spring pin into bottom of sliding bracket.
Remove screws securing latch assembly to
inner door panel and remove latch mechanism.
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.
Removal and Disassembly
1.
2.
3.
A.
Place spring over spring pin.
Remove E-clip from latch assembly pins and
pull pins from latch mechanism.
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.
4.
Remove retaining pin from spring pin.
5.
Separate sliding bracket from stationary
bracket.
Page 9 of 68
Secure pins into position with E-clip.
F35453 (July 2008)
MODEL C24EA - DOOR
Installation
8.
1.
Do not drive bearing into place. The inner
door panel could be damaged. Press bearing into
position.
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.
NOTE: When replacing door hinge bearings, replace
both hinge bearings.
9.
2.
Install outer door housing assembly as outlined
under DOOR HANDLE.
3.
Check opening and closing operation of door.
4.
Check steamer for proper operation and leaks
around door seal.
HINGE BEARINGS
Position replacement hinge bearing over hinge
opening in door assembly.
A.
Close door.
2.
Remove COOKING COMPARTMENT LEFT
SIDE PANEL as outlined under COVERS AND
PANELS.
Remove nuts from upper hinge located inside
front panel.
10. Reassemble parts removed in reverse order.
11. Check door for fit and proper door gasket
sealing.
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.
4.
Open door slightly, and while holding door, pull
upper hinge away from front 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.
F35453 (July 2008)
Press hinge bearing fully into door
assembly using a C-clamp or equivalent.
DOOR LATCH ADJUSTMENT
1.
3.
Remove outer door housing.
Page 10 of 68
If door does not open, remove COOKING
COMPARTMENT RIGHT SIDE PANEL as
outlined under COVERS AND PANELS.
MODEL C24EA - DOOR
B.
C.
Locate the striker that catches on door
latch near steam chamber on front panel.
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.
Remove the 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.
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.
Page 11 of 68
F35453 (July 2008)
MODEL C24EA - THERMOSTATS AND HIGH LIMITS
THERMOSTAT AND HIGH LIMITS
HEAT EXCHANGER HIGH LIMIT
STEAM GENERATOR HIGH LIMIT
Removal
1.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
2.
Remove RIGHT SIDE BASE PANEL as
outlined under COVERS AND PANELS.
3.
Disconnect electrical lead wires from heat
exchanger high limit.
2.
Remove FRONT BASE PANEL as outlined
under COVERS AND PANELS.
4.
Loosen hose clamps securing heat exchanger
high limit to the heat exchanger surface.
3.
Remove heating element (1HTR) from steam
generator as outlined under HEATING
ELEMENTS AND CONTACTORS.
4.
Fully loosen capillary tube compression nut and
slide it away from heating element.
5.
Remove capillary tube mounting nut from
heating element mounting plate.
6.
Disconnect electrical wiring to high limit.
7.
Remove high limit from the rear of low voltage
control box.
5.
1.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
A.
Turn off water supply.
Remove heat exchanger high limit.
6.
Reassemble parts removed in reverse order.
7.
Check steamer for proper operation.
F35453 (July 2008)
Page 12 of 68
MODEL C24EA - THERMOSTATS AND HIGH LIMITS
4.
Secure high limit to low voltage control box then
coil excess capillary tube length near the high
limit.
5.
Check steamer for proper operation and leaks
around heating element gasket and high limit
capillary tube nuts.
CONDENSATE THERMOSTAT
1.
RIGHT SIDE SHOWN
8.
A.
Remove capillary tube from heating element.
Installation
1.
Route capillary bulb through the opening in
heating element mounting plate. Ensure there
are no sharp bends in capillary tubing while
installing.
A.
2.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
Turn off water supply.
2.
Remove RIGHT SIDE BASE PANEL as
outlined under COVERS AND PANELS.
3.
Disconnect electrical wiring to condensate
thermostat.
4.
Remove condensate thermostat from the rear of
drain box.
Insert capillary bulb into the holding tube
on heating element.
Apply pipe thread sealant to threads then install
large capillary tube mounting nut.
A.
Ensure capillary bulb is centered in the
holding tube. Tighten the capillary tube
compression nut.
REAR OF DRAIN BOX SHOWN
3.
5.
Reassemble parts removed in reverse order.
Apply pipe thread sealant to threads of
thermostat before assembly.
6.
Check steamer for proper operation and leaks
around condensate thermostat.
Install heating element with a new gasket.
Torque mounting nuts to 70 in-lbs and tighten
using an alternating pattern.
Page 13 of 68
F35453 (July 2008)
MODEL C24EA - TIMERS
TIMERS
REMOVAL AND REPLACEMENT
NOTE: When the timer reaches zero, an external
buzzer will sound and steam will stop entering the
cooking compartment. The constant steam setting
allows for continuous steam operation.
1.
Remove COOKING COMPARTMENT RIGHT
SIDE PANEL as outlined under COVERS AND
PANELS.
2.
Note electrical connections then disconnect
wiring from timer being serviced.
4.
Reverse procedure to install.
5.
Check steamer for proper operation.
UPPER COMPARTMENT SHOWN
3.
Pull knob from timer shaft.
A.
Remove rotary shaft seal from timer shaft
then remove timer from front panel.
B.
Inspect rotary shaft seal. Replace if
damaged, worn or signs of moisture
migration into control area around timer
shaft is evident.
F35453 (July 2008)
Page 14 of 68
MODEL C24EA - HEATING ELEMENTS AND CONTACTORS
HEATING ELEMENTS AND CONTACTORS
REMOVAL AND REPLACEMENT
Heating Elements
1.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
A.
Turn off water supply.
2.
Remove FRONT BASE PANEL as outlined
under COVERS AND PANELS.
3.
Remove top screw securing cover to high
voltage box.
4.
Note electrical connections for the heating
element being replaced then disconnect heating
element lead wires from contactors.
HEATING ELEMENT (1HTR) WITH STEAM
GENERATOR HIGH LIMIT SHOWN
6.
A.
If replacing heating element (1HTR),
remove STEAM GENERATOR HIGH
LIMIT.
B.
Pull heating element out of steam
generator.
Reassemble parts removed in reverse order.
Torque mounting nuts to 70 in-lbs and tighten
using an alternating pattern.
NOTE: When installing heating element 2HTR or
3HTR, install pipe plug in the center of heating
element mounting plate. Apply pipe thread sealant to
threads before assembly. Use a new gasket
whenever installing a heating element.
5.
Remove mounting nuts and lock washers
securing heating element to steam generator.
NOTE: Refer to STEAM GENERATOR HIGH LIMIT
for proper placement of capillary bulb.
7.
Page 15 of 68
Check steamer for proper operation and leaks
around heating element.
F35453 (July 2008)
MODEL C24EA - HEATING ELEMENTS AND CONTACTORS
Contactors
HEATING ELEMENTS
DIAGNOSTIC CHECK
1.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
2.
Remove FRONT BASE PANEL as outlined
under COVERS AND PANELS.
3.
Remove top screw securing cover to high
voltage box.
4.
Note electrical connections for the contactor
being replaced then disconnect lead wires from
contactor terminals and coil.
5.
Remove screws securing contactor to high
voltage control box then remove contactor.
1.
2.
6.
Reassemble parts removed in reverse order.
7.
Check steamer for proper operation.
Check voltage across heating element lead
wires at the limiting and regulating contactor
terminals and verify against data plate.
A.
If voltage is correct, check current draw
(step 2).
B.
If voltage is not correct, check the
following:
1)
Voltage supply to steamer.
2)
Fuses or breaker blown.
3)
Power to contactor coils.
4)
Contactors not pulling in (mechanical
problem).
Check current draw (amps) through heating
element lead wires using an amp clamp meter.
NOTE: Checking current draw is the preferred
method over a resistance check when an amp clamp
meter is available.
A.
If current is correct, then heating element is
ok. See table for proper values.
B.
If current is not correct, turn power switch
off and disconnect power to machine.
1)
F35453 (July 2008)
Page 16 of 68
Install a replacement heating element.
MODEL C24EA - HEATING ELEMENTS AND CONTACTORS
3.
4.
If unable to check current draw, a resistance check may indicate a malfunctioning element.
A.
Turn power switch off and disconnect power to machine.
B.
Disconnect heating element lead wires and check the individual element resistance using a VOM.
C.
If resistance readings are not correct, replace heating element.
Check steamer for proper operation.
VOLTAGE
KW PER
CURRENT PER
ELEMENT
ELEMENT
RESISTANCE PER
ELEMENT (OHMS)
208 1
1
2
8.0
12.8
16.2
240
1
10.5
14.8
16.2
480
2
8.0
9.6
28.8
208
1
8.0
12.8
16.2
240
1
10.5
14.8
16.2
480
2
8.0
9.6
28.8
Dual voltage elements.
480V elements are connected in Wye configuration for 277V across each element.
NOTE: Values in table are nominal. Tolerance is ±10 %.
Page 17 of 68
F35453 (July 2008)
MODEL C24EA - HEAT EXCHANGER ELEMENTS AND RELAYS
HEAT EXCHANGER ELEMENTS AND RELAYS
REMOVAL AND REPLACEMENT
Heat Exchanger Elements
1.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
A.
Turn off water supply.
2.
Remove FRONT BASE PANEL and RIGHT
SIDE BASE PANEL as outlined under COVERS
AND PANELS.
3.
Note electrical connections for the heat
exchanger element being replaced then
disconnect lead wires from heat exchanger
relay and contactor.
NOTE: When installing, align the flat on delime valve
stem and the locking pins on delime valve to the
motorized control assembly.
NOTE: The two electrical plugs on the motorized
control assembly are identical. Note location of
electrical wiring if disconnecting from motorized
control assembly. If the electrical plugs not
connected correctly, the motorized delime valve will
not function.
5.
4.
Remove motorized control assembly from
delime valve. Rotate the assembly CCW
approximately 1/8 turn to disengage from
delime valve.
F35453 (July 2008)
Remove heat exchanger element from heat
exchanger.
NOTE: To access heat exchanger element (1),
remove heat exchanger element (2) and the 3/8"
vent tube on vacuum relief valve (outlet side).
Page 18 of 68
MODEL C24EA - HEAT EXCHANGER ELEMENTS AND RELAYS
HEAT EXCHANGER ELEMENTS
DIAGNOSTIC CHECK
1.
6.
Reassemble parts removed in reverse order.
Apply pipe thread sealant to threads of heat
exchanger element before assembly.
7.
Check steamer for proper operation and leaks
around heat exchanger element.
Check voltage across heat exchanger element
lead wires at the limiting and regulating
contactor terminals and verify against data
plate.
A.
If voltage is correct, check current draw
(step 2).
B.
If voltage is not correct, check the
following:
1)
Voltage supply to steamer.
Heat Exchanger Relays (K10, K12)
2)
Fuses or breaker open.
1.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
3)
2.
Remove FRONT BASE PANEL as outlined
under COVERS AND PANELS.
Heat exchanger relay (K10) (heat
exchanger element 1) or heat
exchanger relay (K12) (heat
exchanger element 2).
3.
Remove top screw securing cover to high
voltage control box.
4)
Power to contactor coils.
5)
4.
Note electrical connections for the heat
exchanger relay being replaced then disconnect
lead wires from relay terminals and coil.
Contactors not pulling in (mechanical
problem)
5.
Remove screws securing heat exchanger relay
to high voltage control box then remove relay.
2.
Check current draw (amps) through heat
exchanger element lead wires using an amp
clamp meter.
NOTE: Checking current draw is the preferred
method over a resistance check when an amp clamp
meter is available.
A.
If current is correct, then heat exchanger
element is ok. See table for proper values.
B.
If current is not correct, turn power switch
off and disconnect power to machine.
1)
6.
Reassemble parts removed in reverse order.
7.
Check steamer for proper operation.
Page 19 of 68
Install replacement heat exchanger
element.
F35453 (July 2008)
MODEL C24EA - HEAT EXCHANGER ELEMENTS AND RELAYS
3.
4.
If unable to check current draw, a resistance check may indicate a malfunctioning element.
A.
Turn power switch off and disconnect power to machine.
B.
Disconnect heat exchanger element lead wires and check resistance using a VOM.
C.
If resistance is not correct, replace heat exchanger element.
Check steamer for proper operation.
MODEL
C24EA6
C24EA10
1
2
VOLTAGE
WATTS PER
ELEMENT
CURRENT PER
ELEMENT
RESISTANCE PER
ELEMENT (OHMS)
208 1
450
2.20
96.1
1
600
2.50
96.0
480 2
600
2.20
128.0
208
1
600
2.90
72.1
240
1
800
3.30
72.0
480 2
800
2.90
95.9
240
Dual voltage elements.
480V Elements are connected in Wye configuration for 277V across each element.
NOTE: Values in table are nominal. Tolerance is ±10 %.
F35453 (July 2008)
Page 20 of 68
MODEL C24EA - WATER LEVEL CONTROL COMPONENTS
WATER LEVEL CONTROL COMPONENTS
WATER LEVEL CONTROL - LOW LEVEL CUT-OFF AND
DIFFERENTIAL OPERATION
The steamer is equipped with three water level sensing probes
(high, low and low level cut-off) and a water level control. The
water level control performs two functions:
1. Provide low level cut-off protection to shut off the heat
source in case the water level drops below the low level
cut-off (LLCO) probe.
2. Perform as a differential level control to maintain the water
level between the low and high water level probes.
The water level control (WLC) has input voltage (120VAC) across terminals 11 and 12 which powers the primary
side of the transformer. On one side of the transformer secondary, power is provided to the control by a series
path through chassis ground (terminal 10). The other side of the transformer secondary (12VAC) is attached to the
probe that directs power to the other side of WLC relay coils (LLCO and HL) and to the inverse latching relay
(ILR) electronic circuit on the WLC. As water enters the steam generator, it becomes part of the WLC circuit. When
the water level in the steam generator reaches a probe, that circuit is completed.
The inverse latching relay of the WLC is de-energized, leaving the ILR-1 (N.O.) and ILR-2 (N.C.) contacts in their
shelf state.
When the main power switch is turned on, power is supplied to the WLC which energizes the high level (HL) relay,
closes HL-1 normally open contacts, and illuminates the HL relay LED. With the HL-1 contacts closed, the slow fill
solenoid is energized and water begins filling the steam generator.
When the water level reaches the low level cut-off (LLCO) probe, the LLCO relay is energized and illuminates the
LLCO LED. With the LLCO-1 contacts closed, the heat source can be energized provided the auxiliary control(s) in
the heating circuit are satisfied. The LLCO relay will remain energized and its LED will stay lit until the water level
in the steam generator drops below the LLCO probe.
When the water level reaches the low level (LL) probe, power to terminal 2 on the WLC is present but no switching
occurs.
After the water level reaches the high level (HL) probe, the inverse latching relay of the WLC is energized and
locked through the low level probe (LL) and ILR-1 contacts. With ILR-2 contacts open, HL relay is de-energized
and the HL LED goes out. With the HL-1 contacts open, the slow fill solenoid is de-energized, stopping the flow of
water into the steam generator.
When the water level drops below the low level (LL) probe, power is removed from the inverse latching relay, the
HL relay energizes through ILR-2 and HL contacts change state. The slow fill solenoid is energized through HL-1
to refill the steam generator and the HL LED is lit. The HL relay and LED will toggle on and off during a cooking
cycle as needed.
Page 21 of 68
F35453 (July 2008)
MODEL C24EA - WATER LEVEL CONTROL COMPONENTS
WATER LEVEL CONTROL
WATER LEVEL PROBES
1.
Remove FRONT BASE PANEL as outlined
under COVERS AND PANELS.
2.
Squeeze tab on plastic standoffs (5) to release
water level control.
1.
Remove RIGHT SIDE BASE PANEL as
outlined under COVERS AND PANELS.
2.
Note locations of electrical wiring and
disconnect lead wires to water level probes.
WATER LEVEL PROBE ELECTRICAL
CONNECTIONS
Water Level
Wiring
Water Level
Control
Probe
H
# 5 A - Blue
H - High Level
L
# 6 B - Yellow
L - Low Level
LLCO - Low Level
LLCO
# 7 C - Red
Cut-Off
3.
3.
Note electrical connections then disconnect
lead wires from water level control (WLC). Refer
to the machine schematic when installing water
level control.
4.
Reassemble parts and lead wires removed in
reverse order.
5.
Check steamer for proper operation.
Remove probes from probe housing.
NOTE: Probes should be cleaned thoroughly.
Remove all accumulated deposits from insulator
using a soft cloth. Do not use anything abrasive on
insulators. If probes are dirty, delime steam
generator after assembling.
NOTE: Apply pipe thread sealant to threads of probe
before installation.
4.
Reverse procedure to install.
NOTE: Perform steam generator DELIMING.
F35453 (July 2008)
Page 22 of 68
MODEL C24EA - WATER LEVEL CONTROL COMPONENTS
FILTERED AND NON-FILTERED
DUAL WATER SOLENOID
VALVES
NOTE: The filtered and non-filtered water solenoid valves are constructed as dual water valve assemblies. The
two water valve assemblies used on the steamer have different flow rates and should not be interchanged.
DUAL WATER VALVE FLOW RATES (GPM)
1.
Filtered Water
Fast Fill/Flush Valve
Slow Fill Valve
(Steam Generator Fill)
(3SOL)
(4SOL)
4.8
0.28
Non-Filtered Water
Cavity Condensate Valve
Drain Cooling Valve
(Condensate/Drain Cooling)
(2SOL)
(1SOL)
3.8
3.8
Turn off machine to drain steam generator. Allow steamer to complete drain cycle.
A.
Turn off water supply.
2.
Disconnect incoming water to the dual water solenoid valve being replaced (filtered or non-filtered).
3.
Remove RIGHT SIDE BASE PANEL as outlined under COVERS AND PANELS.
4.
Note electrical connections then disconnect wires from solenoid valve.
5.
Note hose connections then disconnect hoses from the outlet of solenoid valve.
NOTE: Use new band clamps when connecting hoses. See TOOLS.
DUAL WATER VALVES SHOWN
Page 23 of 68
F35453 (July 2008)
MODEL C24EA - WATER LEVEL CONTROL COMPONENTS
6.
Remove screws (2) securing dual water
solenoid valve to rear panel.
7.
Reassemble parts removed in reverse order.
8.
Verify water supply is connected to the correct
dual water solenoid valve (filtered or non
filtered).
9.
Check steamer for leaks and proper operation.
5.
MOTORIZED DRAIN VALVE
1.
Push in on the manual drain override knob to
disengage the gear set.
A.
Rotate knob CW to manually open the
drain valve. When the slot in knob is
vertical, the drain valve is open. When the
slot in knob is horizontal, the drain valve is
closed.
B.
Return manual drain override knob to the
closed position.
Turn power switch off.
A.
Allow steamer to complete drain cycle.
B.
If motorized drain valve has malfunctioned
and the steam generator will not drain
normally, refer to Drain Steam Generator
Manually for draining procedure.
Drain Steam Generator Manually
1.
Turn off water supply to steamer.
2.
Disconnect power to steamer allowing time for
water in steam generator to cool to 140EF
before attempting to manually open drain valve.
3.
Remove RIGHT SIDE BASE PANEL as
outlined under COVERS AND PANELS.
4.
Locate motorized drain valve found at the front
of steam generator.
F35453 (July 2008)
Removal
1.
Turn off water supply to steamer.
2.
Remove RIGHT SIDE BASE PANEL as
outlined under COVERS AND PANELS.
3.
Remove motorized control assembly from drain
valve. Rotate motorized control assembly CCW
approximately 1/8 turn to disengage assembly
from drain valve.
Page 24 of 68
MODEL C24EA - WATER LEVEL CONTROL COMPONENTS
8.
Reassemble parts removed in reverse order.
Apply pipe thread sealant to pipe threads before
installation.
NOTE: If motorized drain valve is in the open
position when power is applied to the steamer with
the power switch on, drain valve will not close and fill
water will flow through the steam generator into the
drain.
9.
Verify power switch is in the off position and the
motorized drain valve is closed before applying
power to steamer.
NOTE: When power is applied and power switch is
off steamer will enter a drain cycle.
10. Check steamer for proper operation and leaks
around drain valve.
NOTE: When installing, align the flat on delime valve
stem and the locking pins on delime valve to the
motorized control assembly.
NOTE: The two electrical plugs on the motorized
control assembly are identical. If the electrical wiring
is not connected correctly, the motorized drain valve
will not function.
4.
Note location of electrical wiring then disconnect
from motorized control assembly.
5.
Disconnect drain and drain cooling hoses from
pipe tee located below drain valve.
NOTE: Use new band clamps when connecting
hoses. See TOOLS.
6.
Remove drain valve from steam generator.
7.
Remove pipe tee and nipple plumbing assembly
from drain valve.
Page 25 of 68
F35453 (July 2008)
MODEL C24EA - SWITCHES, SOLENOIDS, RELAY, AND BUZZER
SWITCHES, SOLENOIDS, RELAYS AND BUZZER
POWER AND DELIME SWITCHES
NOTE: If replacing the switch assembly (gaskets,
power and delime switches), remove the switch
bezel from the front panel.
5.
Reassemble parts removed in reverse order.
6.
Check steamer for proper operation.
DOOR SWITCH
1.
Remove COOKING COMPARTMENT RIGHT
SIDE PANEL as outlined under COVERS AND
PANELS.
2.
Locate switch on front panel.
Removal
1.
Remove COOKING COMPARTMENT RIGHT
SIDE PANEL as outlined under COVERS AND
PANELS.
2.
Open cooking compartment door.
3.
Note electrical connections then disconnect
lead wires from switch.
LOWER COMPARTMENT SHOWN
3.
Disconnect electrical plug from the switch being
replaced.
4.
Remove switch from bezel on the front panel.
UPPER COMPARTMENT SHOWN
4.
F35453 (July 2008)
Page 26 of 68
Remove switch from the door switch mounting
bracket. Retain hardware.
MODEL C24EA - SWITCHES, SOLENOIDS, RELAY, AND BUZZER
Installation
1.
2.
3.
Verify E-clip is installed on door switch linkage
in groove nearest front panel.
Remove FRONT BASE PANEL as outlined
under COVERS AND PANELS.
3.
Locate pressure switch on the left side of the
switch piping assembly.
4.
Disconnect electrical wiring to pressure switch.
5.
Remove pressure switch from piping.
6.
Reassemble parts removed in reverse order.
Loosely install door switch onto door switch
mounting bracket.
A.
Close door.
B.
Push switch up against switch linkage as
far as possible.
C.
Tighten switch mounting hardware.
Check door switch operation.
A.
B.
4.
2.
Set meter to measure resistance and place
meter leads across the COMMON and
NORM OPEN terminals of switch. With
door closed, meter should indicate a
closed circuit.
Open door. Meter should indicate an open
circuit as door is opened.
Check steamer for proper operation.
PRESSURE SWITCH (1PAS)
A.
Apply pipe thread sealant to threads of
pressure switch before installation.
B.
Verify Mylar cover is in position covering
electrical connections.
NOTE: Refinement of pressure switch cut-out setting
is found under Adjustment. Always check and adjust
pressure switch setting whenever pressure switch is
being serviced.
C.
If pressure switch is being replaced, check
the initial pressure switch setting using the
reference scale on the pressure switch.
The top surface of adjustment wheel
should be aligned slightly below the 5 psi
mark on pressure switch.
Removal
1.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
7.
Page 27 of 68
Perform pressure switch Check.
F35453 (July 2008)
MODEL C24EA - SWITCHES, SOLENOIDS, RELAY, AND BUZZER
NOTE: Operating pressures will vary slightly
between machine being serviced and gauge
used.
Check
NOTE: Pressure can be checked with the small air
pocket that exists between the delime port cap and
water level probe housing in the delime hose. Make
certain that no leaks exist in the steam generator
connections or pressure gauge fittings.
1.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
2.
Remove FRONT BASE PANEL as outlined
under COVERS AND PANELS.
3.
Remove cap from delime port and install
pressure gauge.
7.
8.
While observing pressure gauge, listen for
contactor to release indicating that pressure
switch contacts have opened. Correct range for
pressure switch cut-out is between 3.5 to 3.7
psi.
A.
Listen for switch contacts to close
(contactor will energize).
B.
Observe pressure gauge for three
complete cycles to find the average cut-out
pressure. Record pressure.
C.
If pressure is outside tolerance (3.5 to 3.7
psi), adjustment is necessary. Refer to
Adjustment.
D.
If cut-out pressure is within specifications,
turn power switch off. Allow time for
steamer to drain.
Remove test gauge and reinstall delime cap.
Adjustment
1.
Allow steam production to stabilize as outlined
under Check.
NOTE: Make small incremental adjustments (1/8
turn of toothed adjustment wheel) when adjusting
cut-out pressure.
2.
4.
Close cooking compartment doors.
5.
Mark one tooth of pressure switch adjustment
wheel to aid in identifying position of wheel.
Make a second mark on body of pressure
switch in alignment with mark on adjustment
wheel.
6.
Turn on machine and allow to pressurize (ready
light on).
A.
Set one cook timer for approximately 15
minutes.
B.
Allow steamer to cycle three times for
steam production to stabilize.
F35453 (July 2008)
Page 28 of 68
Referring to cut-out pressure recorded in Check
procedure, turn adjustment wheel to bring cutout pressure into tolerance.
A.
From looking down on pressure switch:
1)
Turn adjustment wheel CCW to
decrease cut-out pressure.
2)
Turn adjustment wheel CW to
increase cut-out pressure.
MODEL C24EA - SWITCHES, SOLENOIDS, RELAY, AND BUZZER
B.
Check cut-out pressure after making
adjustment. Repeat Check and Adjustment
as necessary until cut-out pressure is
within 3.5 to 3.7 psi.
VACUUM RELIEF SOLENOID
PRESSURE SWITCH (2PAS)
1.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
2.
Remove FRONT BASE PANEL as outlined
under COVERS AND PANELS.
3.
Locate pressure switch on the right side of the
switch piping assembly.
1.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
2.
Remove RIGHT SIDE BASE PANEL as
outlined under COVERS AND PANELS.
3.
Locate vacuum relief solenoid connected to the
water level probe housing and condensate coil.
4.
Disconnect electrical wiring to solenoid coil.
5.
Disconnect compression fitting from the outlet
side of solenoid valve.
A.
4.
Disconnect electrical wiring to pressure switch.
5.
Remove pressure switch from piping.
6.
Reassemble parts removed in reverse order.
A.
7.
6.
Reassemble parts removed in reverse order.
A.
Apply pipe thread sealant to threads of
pressure switch before installation.
Check steamer for proper operation.
7.
Page 29 of 68
Remove solenoid from the pipe nipple and
tee connected to water level probe
housing.
When installing solenoid valve, use two
wrenches to avoid bending condensate coil
tubing. Install valve with the outlet side of
valve connected to the vent tubing that
leads to the floor (behind drain box). Apply
pipe thread sealant to pipe threads before
assembly.
Check steamer for proper operation.
F35453 (July 2008)
MODEL C24EA - SWITCHES, SOLENOIDS, RELAY, AND BUZZER
COMPARTMENT STEAM
SOLENOID
1.
2.
3.
TIME DELAY RELAY
1.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
Turn off machine to drain steam generator.
Allow steamer to complete drain cycle.
2.
Remove RIGHT SIDE BASE PANEL as
outlined under COVERS AND PANELS.
Remove FRONT BASE PANEL as outlined
under COVERS AND PANELS.
3.
Locate compartment steam solenoid connected
to cooking compartment.
Note electrical connections for the time delay
relay then disconnect lead wires from relay.
4.
Remove screw securing relay to low voltage
control box then remove relay.
5.
Reassemble parts removed in reverse order.
6.
Check steamer for proper operation.
LOWER COMPARTMENT SOLENOID SHOWN
4.
Disconnect electrical wiring to solenoid coil.
5.
Disconnect steam hose from the outlet side of
solenoid.
NOTE: Use new band clamps when connecting
hoses. See TOOLS.
6.
NOTE: When installing, ensure time delay knob is
rotated fully CCW to the lowest setting (approx. 2
seconds). Remove jumper wire for proper operation
at steamer control circuit voltage (120VAC).
Remove solenoid from steam supply manifold.
A.
Remove pipe fittings from solenoid.
7.
Reassemble parts removed in reverse order.
Apply pipe thread sealant to pipe threads before
installation.
8.
Check steamer for proper operation.
F35453 (July 2008)
Page 30 of 68
MODEL C24EA - SWITCHES, SOLENOIDS, RELAY, AND BUZZER
BUZZER
1.
Remove COOKING COMPARTMENT RIGHT
SIDE PANEL as outlined under COVERS AND
PANELS.
2.
Locate buzzer on the door switch mounting
bracket.
3.
Disconnect electrical wiring from the buzzer and
door switch.
4.
Remove door striker.
5.
Remove remaining hardware securing door
switch mounting bracket to front panel then
remove door switch mounting bracket, door
switch and buzzer as an assembly.
6.
Remove buzzer from door switch mounting
bracket.
7.
Reassemble parts removed in reverse order.
Perform DOOR LATCH ADJUSTMENT as
outlined under DOOR.
Page 31 of 68
F35453 (July 2008)
MODEL C24EA - CONTROL BOARD
CONTROL BOARD
REMOVAL AND REPLACEMENT
1.
Remove FRONT BASE PANEL as outlined under COVERS AND PANELS.
2.
Disconnect electrical connectors from control board.
3.
Squeeze tab on plastic standoffs (10) to release control board.
4.
Reassemble parts removed in reverse order.
5.
Check steamer for proper operation.
NOTE: When installing, ensure the board jumpers are set to factory defaults as follows: Delime time delay relay
jumper set to 60 minutes; drain time delay relay jumper set to 3 minutes; and machine type set to floor model.
F35453 (July 2008)
Page 32 of 68
MODEL C24EA - CONTROL BOARD
LAYOUT AND LED LEGEND
The control board provides a central location for wire harness connections and power transfer through board
relays (K1-K9, and K11) and time delay relays (delime 1, delime 2 and drain) to the steamer controls. Also,
provides a condition or component troubleshooting indicator by utilizing eighteen LED’S on the board.
LED LEGEND
LED ON = Condition satisfied or component energized. LED OFF = Condition not satisfied or component de-energized.
LED
Component
1
Board powered (120VAC).
2
Limiting contactor (1CON).
LED
Component
10
Drain relay (K3).
11
Drain relay (K5).
3
Regulating contactor 1 (2CON).
1
12
Vacuum relief solenoid (2SOL). 4
4
Regulating contactor 2 (3CON). 2
13
Delime 1 time delay relay powered.
5
Relay (K1) energized.
14
Delime relay (K4).
Upper cavity relay (K8).
3
15
Delime relay (K2).
7
Lower cavity relay (K9).
3
16
Delime relay (K6).
8
Heat exchanger relay (K10).
17
Delime relay (K7).
9
Drain time delay relay (TDR).
18
High limit relay (K11).
6
1. Contactor will cycle heating elements to maintain steam generator pressure when one or both compartments are in use;
or when idling to maintain pressure when compartments are not in use.
2. Contactor will cycle heating elements as necessary to maintain steam generator pressure when both compartments are
in use.
3. K8 and K9 must be energized for heat exchanger relay (K12) to be energized. Heat exchanger element (2) is then
powered.
4. Allows venting of steam generator.
Page 33 of 68
F35453 (July 2008)
MODEL C24EA - CONTROL BOARD
STEAM GENERATOR OPERATIONAL STATUS
(LED INDICATORS)
Use the tables below to determine the operational status of a component or condition by utilizing the LED
indicators on the board. The sections are divided according to their operational step.
NOTE: If steamer power switch is off when line voltage applied, the steamer enters a timed drain cycle then shuts
off.
Starting Conditions
•
Power and water supplied to steamer.
•
Power switch (1S) off.
•
Delime switch (2S) off (center position).
•
Steamer previously operated and drain cycle timed out.
LED
STATUS
ON
COMPONENT
OFF
DESCRIPTION
1
X
Power to control board (120V)
Main transformer (1T) powered.
9
X
Power to drain (TDR)
Relay timed out, no output to drain circuit.
12
X
Vacuum relief solenoid (2SOL) energized.
Pressure switch closed (2PAS). Allows
venting of steam generator during fill.
13
X
Power to delime 1 (TDR)
Relay timed out, no output to delime circuit.
All other LED's are off.
Power Switch on
•
Power light (3LT) (amber) on.
•
HL LED is on. Water level control powered.
•
Water fills steam generator at fast fill rate.
LED
1
STATUS
ON
X
9
12
13
COMPONENT
OFF
DESCRIPTION
Same as starting conditions
X
X
Power removed from drain (TDR)
K4 relay energized. K4-6/2 contacts open.
Same as starting conditions
X
Power removed from delime 1 (TDR)
All other LED's are off.
F35453 (July 2008)
Page 34 of 68
K4 relay energized. K4-6/2 contacts open.
MODEL C24EA - CONTROL BOARD
Water Level at LLCO Probe
•
LLCO LED is on (water level control) (LED is on until water drops below LLCO probe).
•
All contactors energized (steam generator begins heating).
•
Water fill of the steam generator changes to slow fill rate.
LED
STATUS
ON
1
X
2
X
3
X
4
X
12
X
COMPONENT
OFF
DESCRIPTION
Same as Starting Conditions
Limiting contactor (1CON) energized.
Water level is satisfied (LLCO probe).
Limiting contactor (1CON) will remain
energized with the water level satisfied.
Regulating contactor 1 (2CON) energized.
Pressure switch (1PAS) closed; Heating
elements powered.
Regulating contactor 2 (3CON) energized.
Pressure switch (1PAS) closed; Heating
elements powered.
Same as Starting Conditions
All other LED's are off.
Water Level at Low level (L) Probe
•
Water level control no changes.
•
Control Board no changes.
Water Level at High Level (H) Probe
•
HL LED off (water level control).
•
Water fill of steam generator ends (slow fill valve de-energized).
LED
STATUS
ON
COMPONENT
OFF
DESCRIPTION
1
X
Same as Starting Conditions
2
X
Same as Water Level at LLCO Probe
3
X
Same as Water Level at LLCO Probe
Heating elements remain powered.
4
X
Same as Water Level at LLCO Probe
Heating elements remain powered.
Vacuum relief solenoid (2SOL) deenergized.
Pressure switch opens (2PAS). Allows
steam generator to fully pressurize.
12
X
All other LED's are off.
Page 35 of 68
F35453 (July 2008)
MODEL C24EA - CONTROL BOARD
Steam Generator at Operating Pressure
•
Ready lights (1LT) (green) lit for the upper and lower compartments.
•
All contactors de-energized (heating stops).
LED
STATUS
ON
1
X
2
X
3
5
DESCRIPTION
Same as Starting Conditions
X
4
COMPONENT
OFF
X
X
Same as Water Level at LLCO Probe
Limiting contactor (1CON) remains energized
with the water level satisfied (LLCO probe).
Regulating contactor 1 (2CON) deenergized.
Power removed from heating elements.
Regulating contactor 2 (3CON) deenergized.
Power removed from heating elements.
Contactor will cycle on/off as necessary to
maintain pressure in steam generator with
call for heat from pressure switch (1PAS).
Contactor will cycle on/off as necessary to
maintain pressure in steam generator with
call for heat from pressure switch (1PAS).
Pressure switch opens (1PAS). Power to
cooking compartment controls (except during
delime cycle).
Relay (K1) energized.
All other LED's are off.
Timers Set (Upper and lower Compartments)
•
Cook lights (2LT) (red) lit and cooking compartment steam solenoids energize.
•
Heat exchanger heating elements energize.
•
LED 3 will cycle on/off with Regulating Contactor 1 (2CON) to maintain steam generator pressure.
•
LED 4 will cycle on/off with Regulating Contactor 2 (3CON) to maintain steam generator pressure.
LED
STATUS
ON
COMPONENT
OFF
DESCRIPTION
1
X
Same as Starting Conditions.
2
X
Same as Water Level at LLCO Probe.
5
X
Same as Steam generator at Operating
Pressure.
6
X
Upper cavity relay (K8) energized. 3
Upper compartment timer set.
7
X
Lower cavity relay (K9) energized.
3
Lower compartment timer set.
8
X
Cavity condensate solenoid (2SOL)
energized.
Heat exchanger relay (K10) energized.
Cavity drain water is cooled.
Heat exchanger element (1) powered when
one or both compartment timers are set.
All other LED's are off.
NOTE: No LED is associated with heat exchanger relay (K12). Relays K8 and K9 must both be energized for heat
exchanger relay (K12) to be energized. Refer to SCHEMATIC DIAGRAM.
Water Refill
•
HL LED lit (water level control) (cycles with water level control circuit).
•
Slow fill solenoid begins until water level reaches H (high level ) probe. HL contacts cycle with water level
control circuit as water level raises and lowers between L (low level) and H (high level) probes.
•
Control Board LED's no changes.
F35453 (July 2008)
Page 36 of 68
MODEL C24EA - CONTROL BOARD
Timers Reach Zero (Upper and lower Compartments)
•
Buzzer sounds until timer turned to off, constant or additional time is set.
•
Cook lights (2LT) (red) turn off and cooking compartment steam solenoids de-energize.
•
Heat exchanger heating elements de-energize.
•
LED 3 and 4 will cycle as described under Timers Set (Upper and lower Compartments).
LED
STATUS
ON
COMPONENT
OFF
1
X
Same as Starting Conditions
2
X
Same as Water Level at LLCO Probe.
5
X
Same as Steam generator at Operating
Pressure.
DESCRIPTION
6
X
Upper cavity relay (K8) de-energized. 3
Upper compartment timer timed out.
7
X
Lower cavity relay (K9) energized. 3
Lower compartment timer timed out.
Cavity drain water cooling stops.
X
Cavity condensate solenoid (2SOL) deenergized.
8
Heat exchanger relay (K10) de-energized.
Power removed from heat exchanger
element (1).
All other LED's are off.
Power Switch (1S) off
•
Power light (3LT) (amber) and ready light (1LT) (green) off.
•
Drain valve energized (steam generator begins draining).
•
Condensate thermostat closes (1TAS) and drain cooling solenoid energized (1SOL).
•
HL LED off until water drops below L (low level) probe then turns on (water level control).
•
LLCO led lit until water level drops below LLCO probe (water level control). Fast fill/flush solenoid energized.
•
LED 2 remains lit until water level drops below LLCO probe then turns off. Limiting contactor (1CON) deenergized.
•
LED 10 remains lit during 3 minute drain cycle then turns off.
LED
1
STATUS
ON
X
5
X
12
X
13
DESCRIPTION
Same as Starting Conditions
X
9
COMPONENT
OFF
Pressure switch closed (1PAS). Power
removed from cooking compartment
controls.
Relay (K1) de-energized.
Drain time delay relay (TDR) energized.
Steamer turned off and 3 minute drain cycle
started. Drain transformer (2T) powered.
Drain valve energized and opens.
Vacuum relief solenoid (2SOL) energized.
Pressure switch closed (2PAS). Allows
venting of steam generator during draining.
Delime 1 time delay relay powered.
Output from delime 1 (TDR) load terminal is
not active (delime 1 circuit not powered)
until input voltage trigger is received during
the delime cycle.
X
Drain Cycle Ends
•
LED's 1, 9, 12 and 13 remain lit.
•
All other LED's are off.
•
Steamer is off.
Page 37 of 68
F35453 (July 2008)
MODEL C24EA - CONTROL BOARD
DELIMING CYCLE STATUS
(LED INDICATORS)
•
•
Conditions same as listed under STARTING CONDITIONS.
Delime time delay relay 2 (TDR) and drain time delay relay (TDR) jumpers on the control board are set at their
default times as shown on the schematic.
•
Delime valve closed.
•
Delime solution added to steam generator.
NOTE: Heat exchanger elements are not energized during delime cycle.
Delime Switch On
•
Delime switch pressed to DELIME position (momentary on - hold 2 sec).
•
Power light (3LT) (amber) on.
•
Delime light (4LT) (red) on.
•
HL Led is on. Water level control powered.
•
Water fills steam generator at fast fill rate.
LED
STATUS
ON
COMPONENT
OFF
DESCRIPTION
1
X
Same as starting conditions
12
X
Same as starting conditions
13
X
Power to delime 1 (TDR)
14
X
Delime Relay (K4) energized.
Delime 2 (TDR) powered thru K4-6/4 closed contacts
(N.O.). 120VAC output from delime 2 (TDR) load
terminal for 60 minutes.
Power to heating circuit, power light (3LT) and WLC
thru K4-5/3 closed contacts (N.O.).
15
X
Delime Relay (K2) energized.
K2-6/4 contacts close (powers delime light)
K2-5/1 contacts open. Power to cooking
compartment controls is locked out (no power to
timers or lights).
Power to delime 1 (TDR) input trigger and delime 1
(TDR) is energized. 120VAC output from load
terminal remains on for 3 additional minutes after
power is removed from input trigger to allow heat
exchanger to drain (delime valve energized). Total
time 63 minutes unless canceled (delime 2 TDR
default time of 60 minutes plus delime 1 TDR of 3
minutes).
Delime transformer (3T) powered. Delime valve
energized and opens.
Delime valve end switch contacts close.
17
X
Delime Relay (K7) energized.
K7 powered from delime 1 (TDR) output from load
terminal.
K7-5/1 N.C contacts open. X1 potential removed
from power switch (1S).
K7-5/3 N.O. contacts close. Allows delime 1 (TDR) to
remain powered to hold K7 energized for a delay on
drop out (120VAC output from load terminal remains
on) after K4-6/2 N.C. contacts open.
Relay timed out, no output to delime circuit. LED
remains lit as in Turning Steamer Off.
All other LED's are off.
F35453 (July 2008)
Page 38 of 68
MODEL C24EA - CONTROL BOARD
Water Level at LLCO Probe
•
LLCO LED is on (water level control) (LED is on until water drops below LLCO probe).
•
All contactors energized (steam generator begins heating).
•
Water fill of the steam generator changes to slow fill rate.
LED
STATUS
ON
COMPONENT
OFF
1
X
2
X
3
X
4
X
12
X
Same as Starting Conditions
13
X
Same as Delime Switch On
14
X
Same as Delime Switch On
15
X
Same as Delime Switch On
17
X
Same as Delime Switch On
DESCRIPTION
Same as Starting Conditions
Limiting contactor (1CON) energized.
Water level is satisfied (LLCO probe).
Limiting contactor (1CON) will remain
energized with the water level satisfied.
Regulating contactor 1 (2CON) energized.
Pressure switch (1PAS) closed; Heating
elements powered.
Regulating contactor 2 (3CON) energized.
Pressure switch (1PAS) closed; Heating
elements powered.
All other LED's are off.
Water Level at Low level (L) Probe
•
Water level control no changes.
•
Control Board no changes.
Water Level at High Level (H) Probe
•
HL LED off (water level control).
•
Water fill of steam generator ends (slow fill valve de-energized).
LED
STATUS
ON
COMPONENT
OFF
DESCRIPTION
1
X
Same as Starting Conditions
2
X
Same as Water Level at LLCO Probe
3
X
Same as Water Level at LLCO Probe
Heating elements remain powered.
4
X
Same as Water Level at LLCO Probe
Heating elements remain powered.
Vacuum relief solenoid (2SOL) deenergized.
Pressure switch opens (2PAS). Allows
steam generator to fully pressurize.
12
X
13
X
Same as Delime Switch On
14
X
Same as Delime Switch On
15
X
Same as Delime Switch On
17
X
Same as Delime Switch On
All other LED's are off.
Page 39 of 68
F35453 (July 2008)
MODEL C24EA - CONTROL BOARD
Steam Generator at Operating Pressure
•
All contactors de-energized (heating stops).
LED
STATUS
ON
1
X
2
X
COMPONENT
OFF
DESCRIPTION
Same as Starting Conditions
3
X
4
X
Same as Water Level at LLCO Probe
Limiting contactor (1CON) remains energized
with the water level satisfied (LLCO probe).
Regulating contactor 1 (2CON) deenergized.
Power removed from heating elements.
Regulating contactor 2 (3CON) deenergized.
Power removed from heating elements.
Relay (K1) energized.
Pressure switch opens (1PAS). With Delime
Relay (K2) energized (LED 15 on), K2-5/1
contacts are open to lock out power to the
cooking compartment controls.
5
X
13
X
Same as Delime Switch On
14
X
Same as Delime Switch On
15
X
Same as Delime Switch On
17
X
Same as Delime Switch On
Contactor will cycle on/off as necessary to
maintain pressure in steam generator with
call for heat from pressure switch (1PAS).
Contactor will remain off for the rest of
delime cycle.
All other LED's are off.
Steam Generator Maintains Operating Pressure
•
Heat cycles as necessary to maintain steam generator pressure during the delime cycle.
•
LED 3 will cycle on/off with Regulating Contactor 1 (2CON).
•
LED's 1, 2, 5, 13, 14, 15 & 17 remain on.
•
Water level maintained by water level control circuit. HL LED (water level control) will cycle on/off.
Delime Time Reaches Zero
•
Delime light (4LT) (red) on until time expires on Delime 2 (TDR).
•
Delime cycle heating ends. Limiting contactor (1CON) and regulating contactor 1 (2CON) de-energized.
•
Drain cycle starts (drain TDR energized). Drain valve energized to allow steam generator to drain. Delime valve
energized to allow heat exchanger to drain.
•
Condensate thermostat closes (1TAS) and drain cooling solenoid energized (1SOL).
•
HL LED off until water drops below L (low level) probe then turns on (water level control).
•
LLCO led on until water level drops below LLCO probe (water level control). Fast fill/flush solenoid energized.
•
LED 2 remains lit until water level drops below LLCO probe then turns off. Limiting contactor (1CON) deenergized.
•
LED 10 remains lit during 3 minute drain cycle then turns off.
F35453 (July 2008)
Page 40 of 68
MODEL C24EA - CONTROL BOARD
LED
1
STATUS
ON
COMPONENT
OFF
X
DESCRIPTION
Same as Starting Conditions
3
X
Regulating contactor 1 (2CON) deenergized.
Power removed from heating elements.
5
X
Relay (K1) de-energized.
Pressure switch (1PAS) contacts close.
Drain (TDR) energized thru K4-6/2
contacts.
120VAC output from drain (TDR) load
terminal. Drain circuit energized.
Drain relay (K5) is energized thru delime
valve end switch closed contacts (N.O.).
K5-6/4 contacts close and delime light (4LT)
is lit.
9
X
11
X
12
X
Vacuum relief solenoid (5SOL)
energized.
13
X
Same as Delime Switch On
14
K5-5/3 latching circuit close contacts allow
LED 11 to light.
X
Delime Relay (K4) de-energized.
Pressure switch (2PAS) contacts close.
Solenoid valve opens to provide air vent and
allow steam generator to drain.
K4-5/3 contacts open. Power light off.
K4-6/4 contacts open. Power removed from
delime 2 (TDR).
15
X
Delime Relay (K2) de-energized.
K2-6/4 contacts open. Delime light off.
Power removed from delime 1 (TDR) input
trigger, delime 1 (TDR) remains powered
thru K7-5/3 N.O. contacts to hold delime
relay (K7) energized for a delay on dropout
(120VAC output from load terminal remains
on). Allows heat exchanger to drain (along
with steam generator during the 3 minute
drain cycle time.
K2-5/1 contacts open. Power to cooking
compartment controls no longer locked out.
17
X
Same as Delime Switch On
All other LED's are off.
Delime Cycle Ends
•
LED's 1, 9, 12 and 13 remain lit.
•
All other LED's are off.
•
Steamer is off.
Page 41 of 68
F35453 (July 2008)
MODEL C24EA - HEAT EXCHANGER
HEAT EXCHANGER
REMOVAL AND REPLACEMENT
1. Turn off machine to drain steam generator. Allow
steamer to complete drain cycle.
A.
Turn off water supply.
2. Remove FRONT and RIGHT SIDE BASE
PANELS as outlined under COVERS AND
PANELS.
3. Disconnect heat exchanger element wiring as
outlined under HEAT EXCHANGER ELEMENTS
AND RELAYS.
4. Remove control assembly from MOTORIZED
DELIME VALVE.
5. Disconnect lead wires from HEAT EXCHANGER
HIGH LIMIT.
6. Disconnect steam hoses from heat exchanger
and separate union.
8. Remove the following parts from heat exchanger
for reuse:
NOTE: Use new band clamps when connecting
hoses. See TOOLS.
A.
Heat exchanger elements.
B.
Heat exchanger high limit.
C.
Delime valve, pipe nipple and union.
D.
Hose barb fittings.
9. If removed or replacing the heat exchanger,
install insulation around the heat exchanger.
Secure into position using high temperature
aluminum foil tape.
10.
Reinstall parts removed in reverse order.
Apply pipe thread sealant to all pipe
threads connected to the heat exchanger.
Do not apply thread sealant to fill union
fitting.
11.
Check steamer for proper operation.
Inspect all connections to the heat
exchanger for leaks.
7. Remove heat exchanger.
A.
Lift heat exchanger off rear support bracket
and move it away from union. Tilt front of
heat exchanger down and lower it onto the
bottom frame cover.
B.
Rotate heat exchanger and remove it from
steamer.
F35453 (July 2008)
Page 42 of 68
MODEL C24EA - HEAT EXCHANGER
MOTORIZED DELIME VALVE
NOTE: The motorized delime valve (normally closed)
can be opened or closed manually by pushing in on
the manual override knob on top of the valve to
disengage the gear set. Rotate knob CW to open the
valve (slot in knob vertical); or CCW to close the
valve (slot in knob is horizontal).
Removal
1. Turn off power to machine. Allow steamer to
complete drain cycle.
A.
Turn off water supply to steamer.
2. Remove RIGHT SIDE BASE PANEL as outlined
under COVERS AND PANELS.
3. Locate motorized delime valve connected to heat
exchanger.
4. Remove motorized control assembly from delime
valve. Rotate motorized control assembly CCW
approximately 1/8 turn to disengage assembly
from valve.
7. Remove pipe nipple and union from delime valve.
8. Reassemble parts removed in reverse order.
Apply pipe thread sealant to pipe threads before
installation.
9. Verify motorized delime valve is closed before
applying power to steamer.
NOTE: When power is applied and power switch is
off steamer will enter a delime cycle.
10.
Check steamer for proper operation and
leaks around delime valve.
5. Note location of electrical wiring then disconnect
from motorized control assembly.
NOTE: The two electrical plugs on the motorized
control assembly are identical. If the electrical wiring
is not connected correctly, the motorized delime
valve will not function.
NOTE: When installing, align the flat on delime valve
stem and the locking pins on delime valve to the
motorized control assembly.
6. Separate union then remove delime valve from
heat exchanger.
Page 43 of 68
F35453 (July 2008)
MODEL C24EA - STEAM GENERATOR
STEAM GENERATOR
REMOVAL AND REPLACEMENT
1. Turn off machine to drain steam generator. Allow
steamer to complete drain cycle.
A.
Turn off water supply.
2. Remove FRONT, LEFT and RIGHT SIDE BASE
PANELS from generator base and COOKING
COMPARTMENT RIGHT SIDE PANEL as
outlined under COVERS AND PANELS.
3. Remove HEAT EXCHANGER.
4. Remove VACUUM RELIEF SOLENOID.
5. Disconnect compressions fittings then remove
condensate coil tubing.
6. Remove delime hose from water level probe
housing.
NOTE: Use new band clamps when connecting
hoses. See TOOLS.
8. Disconnect compression fitting then remove the
fill piping assembly from steam generator fill tube.
9. Remove MOTORIZED DRAIN VALVE.
7. Disconnect pop-off tubing then remove relief
valve from steam generator.
F35453 (July 2008)
10.
Remove HEATING ELEMENTS from
steam generator.
11.
Remove high voltage control box from
steamer.
Page 44 of 68
A.
Disconnect electrical supply connections
from terminal block and ground.
B.
Disconnect two wiring harness connectors.
MODEL C24EA - STEAM GENERATOR
C.
Remove four bolts securing high voltage
control box to frame.
16.
12.
Remove low voltage control box from
steamer.
A.
Remove the following parts from steam
generator for reuse:
A.
Drip shield (above elements).
B.
Remaining pipe nipples, tees and elbows.
17.
If removed or replacing steam generator,
install insulation around the generator.
Secure into position using high
temperature aluminum foil tape.
18.
Reinstall parts removed in reverse order.
Apply pipe thread sealant to all pipe
threads connected to the steam generator.
19.
Check steamer for proper operation.
Inspect all connections for leaks.
Disconnect wiring harness connector
leading to cooking compartment controls.
DELIMING
Refer to the Installation & Operation manual under
the MAINTENANCE section for specific instructions.
RIGHT SIDE SHOWN
B.
Disconnect delime valve and drain valve
harness connectors from control board.
C.
Remove four bolts securing low voltage
control box to frame.
13.
Remove WATER LEVEL PROBES.
14.
Remove ground wire from water level
probe housing.
15.
Remove hardware securing steam
generator to frame (four places) then
remove generator.
Page 45 of 68
F35453 (July 2008)
MODEL C24EA - ELECTRICAL OPERATION
ELECTRICAL OPERATION
COMPONENT FUNCTION
STEAM GENERATOR CONTROLS
Water Level Control (WLC) . . . . . . . . . . . . . . . Controls water level by monitoring conditions of the three water
level probes H, L and LLCO.
Probe (H)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . High water level probe connected to internal latch relay circuit
on WLC. Water must reach this level before internal latch relay
is energized.
Probe (L) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Low water level probe connected to internal latch relay circuit on
WLC.
Probe (LLCO) . . . . . . . . . . . . . . . . . . . . . . . . . . Low Level Cut-Off (LLCO) probe connected to WLC. Controls
power to heating and fast fill/flush solenoid.
Contactor, (1CON) Limiting . . . . . . . . . . . . . . Connects one side of heating elements to power. Energized
whenever WLC (LLCO) coil is energized.
Contactor 1, (2CON) Regulating . . . . . . . . . . . Connects heating elements to power. On constantly when one
or both cooking compartment timers are set.
Contactor 2, (3CON) Regulating . . . . . . . . . . . Connects heating elements to power. On constantly when both
cooking compartment timers are set.
Elements, Heating . . . . . . . . . . . . . . . . . . . . . . Located in steam generator. Heats water to produce steam.
Elements, Heat Exchanger . . . . . . . . . . . . . . . Two cartridge type heating elements located in the heat
exchanger. Provides additional energy to raise the steam
temperature delivered to the cooking compartments.
Fuse, (1FU & 2FU) . . . . . . . . . . . . . . . . . . . . . . . Slow blow 3A fuse. Located on primary side of main transformer
(1T). Protects control circuitry from over-currents.
Relay, Time Delay . . . . . . . . . . . . . . . . . . . . . . Controlled by delime switch for delime cycle only. Power switch
must be off and delime switch pressed and held for more than 2
seconds to activate time delay relay output and start delime
cycle. Time delay prevents the delime cycle from immediately
starting, if the delime switch is accidentally pressed.
Solenoid (1SOL), Drain Cooling . . . . . . . . . . . Controlled by the condensate thermostat. Mixes cold water with
hot drain water from steam generator to reduce water
temperature at the drain.
Solenoid, (2SOL) Cavity Condensate
Solenoid (3SOL), Fast Fill/Flush
. . . . . . Controlled by cavity relay K8 on control board. Solenoid is
energized when timer is on. Mixes cold water with hot
condensate water from cooking compartment to reduce water
temperature at drain.
. . . . . . . . . . Initial steam generator fill. Used during last stage of drain cycle
to flush drain opening free of debris.
Solenoid (4SOL), Slow Fill . . . . . . . . . . . . . . . Secondary steam generator fill. Energized as necessary to
replenish water in steam generator.
Solenoid (5SOL), Vacuum Relief . . . . . . . . . . . Provides open air line to steam generator during filling and
draining. When generator is draining, keeps a vacuum from
developing to prevent cooking compartment flex; and allows
faster draining. When generator is filling, keeps pressure from
building up to allow the generator to completely fill.
Solenoid, Drain Valve (N.C.) . . . . . . . . . . . . . . Controlled by delime relay K7 and delime circuit operation.
When energized by 24VAC, valve opens to drain the steam
generator.
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Solenoid, Delime Valve . . . . . . . . . . . . . . . . . . Controlled by delime relay K7 and drain circuit operation. When
energized by 24VAC, valve opens to allow deliming of the heat
exchanger and elements during a delime cycle.
Switch (1PAS), Pressure . . . . . . . . . . . . . . . . . Pressure cut-out protection. Range is between 4.5 to 4.7 psi.
Removes power from heating circuit if steam generator pressure
rises above the pressure switch setting.
Switch (2PAS), Pressure . . . . . . . . . . . . . . . . . Vacuum and fill pressure sensing for the steam generator.
When generator is draining, provides power to vacuum relief
solenoid to prevent a vacuum from developing in the steamer.
When generator is initially heating and pressurizes above 4"
W.C. the pressure switch opens to remove power from vacuum
relief solenoid to allow generator to reach operating pressure.
Thermostat (1TAS), Condensate . . . . . . . . . . . Monitors temperature of water entering the facility drain system.
Controls the drain cooling solenoid during cooking operation and
drain cycle (130EF close).
High-Limit (2TAS), Steam Generator . . . . . . . Protects steam generator heating elements from overtemperatures. Capillary tube device (257EF cut-out; 246°F auto
reset).
High-Limit (3TAS), Heat Exchanger . . . . . . . . Protects heat exchanger elements from over-temperatures.
Surface mount device (500EF cut-out; auto reset 450°F).
Transformer (1T), Main . . . . . . . . . . . . . . . . . . Step down transformer from line voltage to 120VAC control
circuit voltage.
Relay, Heat Exchanger (K10) . . . . . . . . . . . . . Connects heat exchanger element (1) to power. On constantly
whenever one or both cooking compartment timers are set.
Relay, Heat Exchanger (K12) . . . . . . . . . . . . . Connects heat exchanger element (2) to power. On constantly
whenever both cooking compartment timers are set.
Control Board . . . . . . . . . . . . . . . . . . . . . . . . . . Controls steam generator operation, draining and deliming
functions. Provides a central location for wire harness
connections and power transfer thru board relays K1 thru K9
and K11 to the steamer controls. Houses 18 LED's for visual
operation status and troubleshooting.
NOTE: The relay’s below are mounted on the control board and are individually replaceable.
Relay (K1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Controlled by pressure switch (1PAS). K1 relay is energized
when the pressure switch N.O. contacts close.
Relay (K2), Delime . . . . . . . . . . . . . . . . . . . . . . Controlled by delime circuit. K2 relay is energized when delime
switch is turned on (momentary).
Relay (K3), Drain Relay . . . . . . . . . . . . . . . . . . Controlled by drain time delay relay. K3 relay is powered when
power switch is turned off and drain time delay is energized for
the drain cycle.
Relay (K4), Delime . . . . . . . . . . . . . . . . . . . . . . Controlled by delime circuit. K4 relay is energized when delime
switch is turned on (momentary).
Relay (K5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Controlled by delime circuit. When delime valve is energized,
the delime valve end switch contacts close and K5 relay is
energized.
Relay (K6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Controlled by delime switch. K6 relay is energized when delime
switch is turned to CANCEL to stop a delime cycle.
Relay (K7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Controlled by delime circuit. K7 relay is energized when delime
time delay relay 1 is energized during delime cycle.
Relay (K8), Cavity
. . . . . . . . . . . . . . . . . . . . . . Controlled by upper cooking compartment timer. When timer is
set, K8 relay is energized and K8- 5/3 contacts close to provide
power to cavity condensate solenoid and heat exchanger relay
(K10). Heat exchanger element (1) energized.
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Relay (K9), Cavity
. . . . . . . . . . . . . . . . . . . . . . Controlled by lower cooking compartment timer. When timer is
set, relay is energized and power is provided thru K8-1/5 N.C.
contacts to cavity condensate solenoid and heat exchanger
relay (K11). Heat exchanger element (2) energized.
Relay (K11), High Limit . . . . . . . . . . . . . . . . . . Controlled by high limit thermostat (2TAS). Relay is energized if
high limit thermostat opens. When high limit closes, relay
remains energized thru K11-5/3 contacts until power is removed
from steamer.
COOKING COMPARTMENT CONTROLS
The upper section of the steamer consists of two separate cooking compartments. Each compartment functions
independently with its own set of controls. Power is supplied to the compartment controls after steam generator
reaches operating pressure.
Switch (1S), Power . . . . . . . . . . . . . . . . . . . . . Controls 120VAC to steam generator control circuit in the on
position. The switch must be in the off position to provide
120VAC to power delime control circuit.
Switch (2S), Delime . . . . . . . . . . . . . . . . . . . . . Controls 120VAC to initially energize delime control circuit
(momentary on). Press and hold switch for approximately 2
seconds to energize external time delay relay and start delime
cycle.
Switch, Door
. . . . . . . . . . . . . . . . . . . . . . . . . . Plunger activated switch wired in series with timer. When switch
is closed and timer is set, regulating contactor(s) are energized
after ready light is on (pressure switch 1PAS satisfied).
Timer, Cooking . . . . . . . . . . . . . . . . . . . . . . . . . Used to set cooking time between 0-60 minutes or select
constant steam. When timer is set, energizes the steam
solenoid valve to allow steam into the cooking compartment.
When time expires, energizes buzzer until timer is turned off.
Buzzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Creates audible signal when timed cook cycle is complete.
Lamp (1LT), Ready
. . . . . . . . . . . . . . . . . . . . . Green (GN) colored lamp. On when door is closed and steam
generator is pressurized (pressure switch 1PAS operated).
Lamp (2LT), Cook . . . . . . . . . . . . . . . . . . . . . . Red (RD) colored lamp. On when door is closed and timer is
set.
Lamp (3LT), Power
. . . . . . . . . . . . . . . . . . . . . Amber (AM) colored lamp. On when power switch is on and
steam generator high limits are closed.
Lamp (4LT), Delime . . . . . . . . . . . . . . . . . . . . . Red (RD) colored lamp. On when power switch is off and delime
switch is operated.
Solenoid, Compartment Steam . . . . . . . . . . . . When energized by timer, steam solenoid opens to allow steam
into cooking compartment (normally closed valve).
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COMPONENT LOCATION
Steam Generator Base
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MODEL C24EA - ELECTRICAL OPERATION
Water Level Control
Cooking Compartment Controls
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SMART CYCLE POWER
MANAGEMENT
Reduces energy use by not powering all the heating elements in steam generator and heat exchanger when the
steamer is at operating pressure and one cooking compartment in use. When both cooking compartments are in
use, all of the heating elements in the steam generator and heat exchanger are powered.
Heating Elements
Steamer
Steam
Generator
Heat
Exchanger
6 pan
2
2
One cooking compartment in use, only one steam generator heating
element and one heat exchanger element are powered thru limiting
contactor (1CON) and regulating contactor 1 (2CON).
10 pan
3
2
One cooking compartment in use, two steam generator heating elements
and one heat exchanger element are powered thru limiting contactor
(1CON) and regulating contactor 1 (2CON).
6 or
10 pan
As listed
above
As listed
above
Two cooking compartments in use, all steam generator heating elements
and both heat exchanger elements are powered thru limiting contactor
(1CON), regulating contactor 1 (2CON) and regulating contactor 2
(3CON).
Description
SEQUENCE OF OPERATION
Refer to the following diagrams when reviewing sequence of operation: Steam generator schematic, cooking
compartment schematic and heating element wiring diagrams (for heat exchanger relay contacts K10 and K12).
The control board delime time delay relay 2 (TDR) and drain time delay relay (TDR) jumpers are set at their default
times as shown on the schematic.
NOTE: If power switch is off when service voltage is applied, steamer will enter timed drain cycle.
Initial Fill and Pre-Heat
1.
Conditions (steamer previously operated and drain cycle timed out).
A.
Steamer connected to correct voltage.
1)
120VAC potential across X1 and X2 on secondary side of main transformer.
B.
Steamer connected to cold water supply with correct water requirements.
C.
LED 1 lit (power to control board).
D.
Power switch is off (1S).
1)
LED 13 lit. Delime 1 (TDR) on control board timed out. Time delay has no output from load
terminal.
2)
Delime 2 (TDR) on control board timed out. Time delay has no output from load terminal.
3)
LED 9 lit. Drain (TDR) on control board timed out. Time delay has no output from load terminal.
E.
Delime switch (2S) is off (center position).
F.
Compartment timers off and doors open.
G.
Condensate thermostat thermostat (1TAS) open.
H.
Pressure switch (2PAS) closed.
1)
LED 12 lit. Vacuum relief solenoid (5SOL) energized. Solenoid valve must be open to provide air
vent to allow steam generator to fill.
I.
Steam generator high limit (2TAS) closed.
J.
Heat exchanger high limit (3TAS) closed.
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MODEL C24EA - ELECTRICAL OPERATION
K.
Pressure switch (1PAS) closed.
L.
Drain valve closed and steam generator is empty.
M.
Delime valve closed and heat exchanger empty.
1)
N.
2.
Water level control (WLC) and steam generator properly grounded.
Power switch turned on (1S).
A.
LED 13 off. Power removed from delime 1 (TDR) on control board.
B.
LED 9 off. Power removed from drain (TDR) on control board.
C.
X1 potential thru steam generator high limit (2TAS) and heat exchanger high limit (3TAS).
1)
Power light (3LT) (amber) on control panel lit.
2)
X1 potential to L1 of water level control (WLC) thru K3-1/5 drain relay N.C. contacts.
3)
3.
Delime valve end switch N.O. contacts are open.
a.
120VAC across L1 and L2 of WLC.
b.
HL LED lit. High level relay coil (HL) on WLC energized.
Fast fill/flush solenoid (3SOL) energized thru WLC (LLCO) N.C. contacts. Steam generator begins
fast fill.
Water level reaches Low Level Cut-Off (LLCO) probe.
A.
LLCO LED lit. Low level coil relay (LLCO) on WLC energized.
B.
LLCO N.C. contacts open. Fast fill/flush solenoid (3SOL) de-energized.
C.
WLC (LLCO) N.O. contacts close. X1 potential thru WLC (LLCO) closed contacts and K3-6/2 N.C. drain
relay contacts.
1)
Slow fill solenoid (4SOL) energized thru pressure switch (1PAS) N.C contacts and WLC (HL) closed
contacts. Steam generator changes to slow fill.
2)
LED 2 lit. Limiting contactor (1CON) energized.
3)
LED 4 lit. Regulating contactor 2 (3CON) energized thru K1-5/1 N.C. contacts.
4)
Heat exchanger relay (K12) energized.
a.
5)
D.
4.
Power to heating elements. Steam generator heating begins.
No action as internal latching relay ILR-1 contacts on WLC are open.
Water level reaches high level (H) probe.
A.
Internal latching relay coil (ILR) on WLC energized and locked thru the low level probe (L) and ILR-1
closed contacts.
B.
HL LED off. High level (HL) coil de-energized by ILR-2 contacts opening on WLC.
1)
6.
WLC (HL) contacts open. Slow fill solenoid (4SOL) de-energized.
Pressure switch (2PAS) operates (approx. 4" W.C.) and N.C. contacts open.
A.
7.
LED 3 lit. Regulating contactor 1 (2CON) energized.
Water level reaches low level (L) probe.
A.
5.
K12-5/3 N.O. contacts close.
LED 12 off. Vacuum relief solenoid (5SOL) de-energized. Solenoid valve must close to allow steam
generator to fully pressurize.
Steam generator up to pressure (approx. 4 psi).
A.
Pressure switch (1PAS) operates and N.C. contacts open.
1)
LED 5 lit. Relay (K1) energized.
a.
K1-5/3 N.O. contacts close. X1 potential thru K1-5/3 contacts and K2-5/1 N.C. contacts to
cooking compartment controls.
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MODEL C24EA - ELECTRICAL OPERATION
a)
b.
K1-5/1 N.C. contacts open.
a)
2)
B.
Ready lights (1LT) (green) are lit for the upper and lower compartments.
LED 4 off. Regulating contactor 2 (3CON) de-energized.
LED 3 off. Regulating contactor 1 (2CON) de-energized.
Power removed from heating elements. Steam generator heating stops.
Timers Set (Upper & Lower Compartments)
1.
Timers set for timed cooking and doors closed.
A.
Upper compartment - Timer contacts 11/13 and 21/23 close.
1)
B.
LED 6 lit. Upper cavity relay (K8) energized. K8-3/5 N.O. contacts close.
a.
LED 8 lit. Cavity condensate solenoid (2SOL) energized. Compartment drain line condensate
cooled.
b.
Heat exchanger relay (K10) energized. K10-3/5 N.O. contacts close and heat exchanger
element (1) begins heating.
c.
K8-6/4 N.O. contacts close.
2)
Cook light (2LT) (red) lit. Steam solenoid energized (steam enters cooking compartment).
3)
Timer motor energized.
Lower compartment - Timer contacts 11/13 and 21/23 close.
1)
LED 7 lit. Lower cavity relay (K9) energized. K9-3/5 N.O. contacts close.
a.
LED 8 lit. With upper compartment timer already set, cavity condensate solenoid (2SOL) and
heat exchanger relay (K10) are energized thru K8-3/5 closed contacts.
a)
2.
K10-3/5 contacts close and heat exchanger element (1) begins heating.
b.
Heat exchanger relay (K12) energized thru K8-6/4 and K9-3/5 N.O. contacts. Heat exchanger
element (2) begins heating.
c.
If lower compartment timer is the only timer set, cavity condensate solenoid (2SOL) and heat
exchanger relay (K10) are energized thru K8-1/5 N.C. contacts. Compartment drain line
condensate is cooled. K10-3/5 contacts close and heat exchanger element (1) is energized.
2)
Cook light (2LT) (red) lit. Steam solenoid energized (steam enters cooking compartment).
3)
Timer motor energized.
Steam generator pressure drops below pressure switch (1PAS) set point.
A.
Regulating contactor 1 (2CON) and regulating contactor 2 (3CON) are energized and power the heating
elements until pressure switch is satisfied. The pressure switch will cycle the heating circuit as necessary
to maintain steam generator pressure.
1)
LED 3 will cycle on/off with regulating contactor 1 (2CON). LED 4 will cycle on/off with regulating
contactor 2 (3CON).
Water Refill (After Initial Fill)
1.
The water refill cycle will occur whenever the water level is below the low level probe and will not affect the
operation of either the preheat or cook cycle.
A.
Water level drops below low level (L) probe.
1)
Internal latching relay coil (ILR) on WLC de-energized. ILR-1 contacts return to N.O. condition.
2)
HL LED lit. High level coil (HL) energized by ILR-2 contacts returning to N.C. condition.
a.
B.
WLC (HL) contacts close. Slow fill solenoid (4SOL) energized.
Water level reaches high level (H) probe.
1)
Internal latching relay coil (ILR) on WLC energized and locked thru the low level probe (L) and ILR1 closed contacts.
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MODEL C24EA - ELECTRICAL OPERATION
2)
HL LED off. High level (HL) coil de-energized by ILR-2 contacts opening.
a.
2.
WLC (HL) contacts open. Slow fill solenoid (4SOL) de-energized.
Timers reach zero (Upper & Lower Compartments).
A.
Upper compartment - Timer contacts 11/13 and 21/23 open.
1)
B.
LED 6 off. Upper cavity relay (K8) de-energized. K8-3/5 contacts return to N.O. condition.
a.
LED 8 off. Cavity condensate solenoid (2SOL) de-energized.
b.
Heat exchanger relay (K10) de-energized. K10- 3/5 contacts return to N.O. condition and heat
exchanger element (1) de-energized.
c.
K8-6/4 contacts return to N.O. condition.
2)
Cook light (2LT) (red) off. Steam solenoid de-energized.
3)
Timer motor de-energized.
Lower compartment - Timer contacts 11/13 and 21/23 open.
1)
LED 7 off. Lower cavity relay (K9) de-energized. K9-3/5 contacts return to N.O. condition.
a.
LED 8 off. With upper compartment timer expired, cavity condensate solenoid (2SOL) and
heat exchanger relay (K10) are de-energized. K8-3/5 contacts are open.
a)
b.
C.
K10-3/5 contacts open and heat exchanger element (1) de-energized.
Heat exchanger relay (K12) de-energized. K8-6/4 and K9-3/5 contacts return to N.O. condition.
Heat exchanger element (2) de-energized.
2)
Cook light (2LT) (red) off. Steam solenoid de-energized.
3)
Timer motor de-energized.
Buzzer energized through timer N.O. contacts 11/14 (upper or lower cooking compartment timer).
1)
Buzzer remains energized until: Timer turned to OFF; New time or CONSTANT steam selected; Or
power switch turned off.
Turning Steamer Off
1.
Timers off (upper and lower cooking compartments).
2.
Power switch (1S) turned off.
A.
3.
Power light (3LT) (amber) on control panel off.
LED 9 Lit. Drain (TDR) energized thru K4-6/2 N.C. contacts. 120VAC output from load terminal on drain
(TDR) for 3 minute (default) drain cycle time.
A.
B.
LED 10 Lit. Drain relay (K3) energized.
1)
K3-3/5 N.O. contacts close. HL LED off; LLCO LED lit. WLC remains powered.
2)
K3-1/5 N.C. contacts open. Prevents possible short circuit in the event power switch is turned on.
3)
K3-6/2 N.C. contacts open. Removes power from heating circuit and compartment controls. Ready
lights (1LT) (green) are off for the upper and lower compartments.
Drain transformer (2T) powered (120/24VAC).
1)
4.
Drain water temperature above 130°F. Condensate thermostat (1TAS) contacts close (N.O. contacts - close
on temperature rise).
A.
5.
24VAC drain valve energized. Valve opens and steam generator begins draining.
Drain cooling valve (1SOL) energized until drain water temperature is below 120°F.
Pressure switch (2PAS) N.C. contacts return to closed condition when steam generator pressure drops below
4" W.C.
A.
LED 12 lit. Vacuum relief solenoid (5SOL) energized. Solenoid valve must be open to provide air vent
and allow steam generator to drain.
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6.
LED 13 Lit. Power to delime 1 (TDR). Time delay relay has no output from load terminal until input trigger
voltage is received by delime switch (2S) at the start of a delime cycle.
7.
Water level drops below low level (L) probe.
8.
A.
Internal latching relay coil (ILR) on WLC de-energized. ILR-1 contacts return to N.O. condition.
B.
HL LED lit. High level coil (HL) energized by ILR-2 contacts returning to N.C. condition. WLC (HL)
contacts close.
Water drops below LLCO probe.
A.
LLCO LED off. Low level relay coil (LLCO) on WLC de-energized.
1)
WLC (LLCO) N.C. contacts return to closed condition.
a.
2)
B.
9.
Fast fill/flush solenoid (3SOL) energized. Water flushes steam generator drain opening to clear
debris.
WLC (LLCO) N.O. contacts return to open condition.
LED 2 off. Limiting contactor (1CON) de-energized.
Drain (TDR) time elapses.
A.
120VAC removed from drain TDR load terminal.
1)
LED 10 off. Drain relay (K3) de-energized. K3 contacts return to normal conditions. Power removed
from WLC.
2)
Power removed from drain transformer (2T). Drain valve de-energized and valve closes.
10. Drain water temperature below 120°F. Condensate thermostat (1TAS) contacts return to open condition.
Drain cooling solenoid (1SOL) de-energized.
11. LED's 1, 9, 12 and 13 lit. Draining complete and steamer is off.
Deliming Cycle
NOTE: Allow steam generator to completely drain and the drain valve to close before adding delime solution.
Refer to Installation & Operation manual for deliming procedure.
1.
Power switch (1S) off and steam generator empty. LED's and components conditions are in the same state as
outlined at the end of Turning Steamer Off.
2.
Press delime switch (2S) to DELIME position (momentary) and hold until delime (4LT) (red) and power (3LT)
(amber) lights are lit (approx. 2 seconds). Release delime switch to return to center off position.
A.
LED 15 lit. Delime relay (K2) energized.
1)
K2-6/4 N.O. contacts close. Delime light (4LT) lit.
2)
Power to delime 1 (TDR) input trigger and delime 1 (TDR) is energized. LED 13 remains lit as in
Turning Steamer off. 120VAC output from load terminal remains on for 3 additional minutes after
power is removed from input trigger to allow heat exchanger to drain (delime valve energized). Total
time 63 minutes unless canceled (delime 2 TDR default time of 60 minutes plus delime 1 TDR of 3
minutes).
3)
B.
a.
Delime transformer (3T) powered. Delime valve energized and opens (approx. 10 second
delay while valve motor capacitor charges).
b.
Delime valve end switch contacts close.
c.
LED 17 lit. Delime relay (K7) energized.
a)
K7-5/1 N.C contacts open. X1 potential removed from power switch (1S).
b)
K7-5/3 N.O. contacts close. Allows delime 1 (TDR) to remain powered during delime cycle
after K4-6/2 N.C. contacts open.
K2-5/1 N.C. contacts open. Power to cooking compartment controls is locked out.
LED 14 lit. Delime relay (K4) energized thru K6-5/1 N.C contacts.
1)
Delime 2 (TDR) powered thru K4-6/4 closed contacts (N.O.). 120VAC output from delime 2 (TDR)
load terminal for 60 minutes.
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MODEL C24EA - ELECTRICAL OPERATION
a.
Delime relay (K2) remains powered. LED 15 remains lit from pressing delime switch (2S).
b.
Power to heating circuit, power light (3LT) (amber) and WLC thru K4-5/3 closed contacts
(N.O.).
a)
3.
Steam generator fills and operates as outlined in steps 2A thru 7B under Initial Fill and
Pre-heat with this exception. After pressure switch (1PAS) is satisfied, LED 4 will remain
off and regulating contactor 2 (3CON) will remain de-energized. LED 3 and regulating
contactor 1 (2CON) will cycle on/off as necessary to maintain steam generator pressure.
After 60 minutes, time expires on delime 2 (TDR).
A.
LED 15 and LED 14 off. Delime relays (K2) and (K4) are de-energized and contacts return to normal
conditions.
1)
Power light (3LT) (amber) off.
4.
With power removed from delime 1 (TDR) input trigger (K2-6/4 contacts open), delime 1 (TDR) remains
powered thru K7-5/3 N.O. contacts to hold delime relay (K7) energized for a delay on dropout (120VAC
output from load terminal remains on). Allows heat exchanger to drain (delime valve energized) along with
steam generator during the 3 minute (default) drain cycle time.
5.
Steamer enters 3 minute drain cycle. Drain cycle operates as outlined in steps 3 thru 8. B. under Turning
Steamer Off. Continue with sequence for remainder of delime cycle operation
A.
With drain (TDR) energized (LED 9 lit) (120VAC output from load terminal); and delime 1 (TDR)
powered (LED 13 lit) and receiving voltage to input trigger terminal; and delime valve end switch
contacts closed.
1)
6.
Drain relay (K5) is energized thru delime valve end switch closed contacts (N.O.).
a.
K5-6/4 contacts close and delime light (4LT) is lit.
b.
LED 11 lit. K5-5/3 latching circuit contacts close.
After 3 minutes, time expires on drain (TDR) and the drain cycle ends. 120VAC removed from drain TDR load
terminal.
A.
LED 10 off. Drain relay (K3) de-energized. K3 contacts return to normal conditions. Power removed from
WLC.
B.
Power removed from drain transformer (2T). Drain valve de-energized and valve closes.
1)
LED 11 off. Delime relay (K5) de-energized. Latching circuit contacts K5-5/3 return to open
condition. Contacts K5-6/4 return to open condition.
a.
Power removed from delime 1 (TDR) input trigger.
b.
Delime light (4LT) off.
7.
Drain water temperature below 120°F. Condensate thermostat (1TAS) contacts return to open condition.
Drain cooling solenoid (1SOL) de-energized.
8.
Time expires on delime 1 (TDR).
9.
A.
Delime transformer (3T) is de-energized. Delime valve closes and delime valve end switch contacts
return to open condition.
B.
Delime relay (K7) de-energized. Contacts K7-5/3 and K7-5/1 return to normal condition.
LED's 1, 9, 12 and 13 lit. Draining complete and steamer is off.
Cancel Deliming
1.
Press delime switch (2S) to CANCEL position (off).
A.
If delime valve has not opened, the steamer is ready to use (approx. 10 second delay while valve motor
capacitor charges). Allows an unintended delime cycle to be canceled.
B.
If delime valve has opened, the steamer will go thru a drain cycle before it can be turned on.
1)
LED 16 lit. Delime relay (K6) energized. K6-5/1 N.C contacts open.
a.
Delime relay (K4) de-energized.
a)
LED 9 lit. K4-6/2 return to N.C condition and drain (TDR) energized.
b)
Drain circuit powered. Steam generator drains and shuts off as outlined under Turning
Steamer Off.
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MODEL C24EA - ELECTRICAL OPERATION
SCHEMATIC DIAGRAMS
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MODEL C24EA - ELECTRICAL OPERATION
Steam Generator Base
F35453 (July 2008)
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MODEL C24EA - ELECTRICAL OPERATION
WIRING DIAGRAMS
Heating Element Wiring
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MODEL C24EA - ELECTRICAL OPERATION
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MODEL C24EA - ELECTRICAL OPERATION
Cooking Compartment
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MODEL C24EA - TROUBLESHOOTING
TROUBLESHOOTING
Before performing any of the troubleshooting checks listed below, remove the front generator base panel and
check the LED’S on the control board for the status of the condition or component in the operating sequence. By
utilizing the troubleshooting LED’S, the Service Technician can easily determine if a component is functioning
properly or in need of repair. Refer to CONTROL BOARD.
SYMPTOM
Drain water not being cooled properly.
Heat coming on without water in steam
generator.
1.
2.
3.
4.
5.
1.
2.
3.
Excessive time for steam generator to reach 1.
operating pressure (over 25 min).
2.
3.
4.
5.
6.
7.
POSSIBLE CAUSES
Water supply off or supply pressure incorrect.
Condensate thermostat (1TAS) malfunction.
Drain cooling solenoid (1SOL) malfunction (clogged).
Cavity condensate solenoid (2SOL) not receiving power.
A. Timer malfunction (upper or lower compartment).
B. Control board upper cavity relay (K8); or lower cavity
relay (K9) malfunction.
Cavity condensate solenoid (2SOL) malfunction (clogged).
Lime scale build-up on water level probes (shorted to ground).
Contactor malfunction.
WLC- LLCO contacts stuck closed. Water level control (WLC)
malfunction.
Supply voltage incorrect.
Heating elements not wired correctly.
Contactor(s) malfunction.
Steam generator not filled. See Symptom - Steam generator
not filling or is slow to fill.
Pressure switch (2PAS) malfunction (not opening).
Vacuum relief solenoid (5SOL) energized or stuck open
(steam generator continues to vent and release pressure).
Cooking compartment steam solenoid stuck open (steam
inside compartment with timer off).
Steamer leaks water.
1.
Loose connections in water, steam or drain lines.
Water running out of drain during fill.
1.
2.
3.
1.
Drain valve (motorized) stuck open.
Control board malfunction (drain TDR).
Condensate thermostat (1TAS) malfunction.
Slow fill solenoid (4SOL) or fast fill/flush solenoid (3SOL) does
not shut off.
Lime scale build-up on high level probe (open circuit).
Water level control malfunction.
Steam generator water level too high.
2.
3.
F35453 (July 2008)
Page 66 of 68
MODEL C24EA - TROUBLESHOOTING
SYMPTOM
Steamer will not heat.
1.
2.
3.
4.
5.
6.
Steam generator not filling or is slow to fill.
7.
8.
9.
10.
11.
12.
13.
14.
1.
2.
3.
4.
5.
6.
7.
8.
9.
Steam leaks around door.
Water leaks around door.
Steam generated inside cooking
compartment when timer is off.
Timer motor does not run
Door not closing properly.
Door won’t open.
Buzzer not operating.
10.
11.
1.
2.
1.
2.
3.
1.
2.
1.
2.
1.
2.
1.
1.
2.
POSSIBLE CAUSES
Check incoming voltage.
Steam generator not filled. See Symptom - Steam generator
not filling or is slow to fill.
Power switch (1S) malfunction.
Steam generator high limit (2TAS) open.
Heat exchanger high limit (3TAS) open.
WLC-LLCO normally open contacts not closed. Water level
control (WLC) malfunction.
Control board drain relay (K3) malfunction.
Limiting (1CON) contactor malfunction.
Pressure switch (1PAS) not adjusted properly or malfunction.
Regulating contactor 1 (2CON) malfunction.
Relay (K1) malfunction.
Regulating contactor 2 (3CON) malfunction.
Heating element(s) inoperative.
Water too pure for probes to properly conduct electricity.
Water supply off, supply pressure incorrect or filtering system
clogged.
Water level control not receiving power. Control board drain
relay (K3) malfunction.
WLC-LLCO normally closed contacts are open (no power to
fast fill/flush solenoid 3SOL). Water level control (WLC)
malfunction.
Fast fill/flush solenoid (3SOL) clogged or malfunction.
WLC-HL normally open contacts are not closing (no power to
slow fill solenoid 4SOL). Water level control (WLC)
malfunction.
Slow fill solenoid (4SOL) clogged or malfunction.
Drain valve (motorized) stuck open.
Pressure switch (2PAS) malfunction (not closed).
Vacuum relief solenoid (5SOL) opening is clogged (not
allowing steam generator to vent).
Lime scale build-up on water level probes (shorted to ground).
Water level control (WLC) malfunction.
Worn or damaged door gasket.
Drain line obstructed or not to an open gap drain.
Steamer not level.
Drain line obstructed or not to an open gap drain.
Worn or gasket Door gasket damaged.
Compartment steam solenoid stuck open.
Timer malfunction.
Door open or door switch malfunction.
Timer malfunction.
Door latch assembly.
Striker adjustment.
Latch won’t release. See DOOR LATCH ADJUSTMENT.
Timer malfunction.
Buzzer malfunction.
Page 67 of 68
F35453 (July 2008)
MODEL C24EA - TROUBLESHOOTING
-NOTES-
F35453 (July 2008)
Printed in U.S.A.
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