AccuTemp N61201D Service Manual
EVOLUTION
NATURAL GAS / PROPANE
SERVICE MANUAL
ACCUTEMP PRODUCTS INC
8415 N. CLINTON PARK DR ● FORT WAYNE, IN 46825 ● 800 480-0415 ● www.accutemp.net
SP8026-1201 Email: service@accutemp.net
IMPORTANT FOR YOUR SAFETY
The Safety Instructions listed on this page below, should be posted
in a prominent location as a reminder of safe practices; as well as,
recommended actions to follow in the event of an equipment
or facility’s utility issue.
WARNING
In the event a GAS ODOR is DETECTED, SHUTDOWN all appliances at the Main Gas Shut-Off
Valve and contact the local Gas Company or Gas Supplier Service.
WARNING
In the event of a Power Failure, DO NOT attempt to operate this appliance.
WARNING
DO NOT store or use Gasoline, or any other Flammable Vapor and/or Liquids in the vicinity of this
or any other appliance.
WARNING
IMPROPER installation, adjustment, alteration, service, or maintenance can cause personal injury
or death; and/or property damage. Read the installation, operation, and service/maintenance
instructions thoroughly; before installing or servicing this equipment.
WARNING
Only QUALIFIED service technicians/electricians should perform the equipment installation, to
ensure that all electrical and safety requirements are met; and that all wiring is performed in
accordance with all national, state, and local electrical codes.
SP8026-1201 i
WARNING SYMBOL DEFINITIONS
SYMBOL DEFINITIONS
Symbols are used to attract your attention to possible dangers. They are only effective if
the operator uses proper accident prevention measures. Some of the symbols are boxed
text; while others maybe just picture icons. Please give this information the respect they
deserve for safe operation.
Warning Text Boxes
Below are denitions of the warning text boxes.
DANGER
Indicates an imminently hazardous situation;
which, if unchanged, will result in death or
serious injury.
WARNING
Indicates a potentially hazardous situation;
which, if unchanged, will result in death or
serious injury.
Symbol Icons
Below are denitions of the symbol icons used
in this manual.
ALERT
Noties the reader of an important
message or warning; usually a
safety related message.
INFORMATION
Noties the reader of an important
information that may or may not
be safety related.
CAUTION -
CAUTION
Indicates a potentially hazardous situation;
which, if unchanged, will result in minor or
moderate injury.
HOT SURFACE
DANGEROUS
VOLTAGE
NOTE
Advises the reader of information or
instructions, vital to the operation or
maintenance of the equipment.
SP8026-1201 ii
EARTH GROUND
SAFETY PRECAUTIONS
DANGER
ELECTRICAL SHOCK HAZARD WHILE WORKING ON
ENERGIZED EQUIPMENT.
Unplug equipment prior to removing any components effected by electricity.
FLAMMABLE GAS HAZARD WHILE WORKING ON GAS
EQUIPMENT.
Shut-Off the Supply Gas Valve to the equipment prior to removing any
components effected by supplied gas.
BURN HAZARD WHILE WORKING ON STEAM PRODUCING
EQUIPMENT.
When accessing the cooking chamber, be sure to always stand back while slowing
opening the door to allow the chamber to vent off the steam. Never reach into the cooking
chamber before it has completely vented off the steam.
Never reach into the cooking chamber or handle hot items without wearing the proper
heat protective gloves. Steam coming out of the holes on the right side of the cooking chamber
is invisible and can cause severe burns.
Water inside the steam chamber, creating steam, has a temperature of 212°F and will
cause burns if touched or spilled on the skin.
PERSONNEL INJURY HAZARD WHILE PICKING UP OR
MOVING HEAVY EQUIPMENT.
Always use 2 people and proper lifting techniques when picking-up, moving, or
ipping-over heavy equipment.
SLIP & FALL HAZARD WHILE WORKING ON WATER
HOLDING EQUIPMENT.
Keep the oor in front of the equipment clean and dry. If spills occur, clean them up
immediately to avoid potential injuries.
SP8026-1201 iii
WARNING & CAUTION NOTES
WARNING
ONLY QUALIFIED SERVICE TECHNICIANS
SHOULD PERFORM MAINTENANCE ON
THIS EQUIPMENT.
CAUTION
DO NOT• use abrasive materials, such as wire brushes or metal scouring pads to
clean the Water Sensors.
DO NOT• use Aluminum Oxide Sandpaper to clean the Water Sensors or Ignitor/
Flame Sense Probes. It leaves a residue that will not allow Water Sensors to work
properly.
DO NOT• manually ll water above the Water Level Mark on the left side of steam
chamber above the High Limit Level Sensor.
SP8026-1201 iv
TABLE OF CONTENTS
SAFETY
Important For Your Safety.......................................................................................................................................i
Warning Symbol Denitions..................................................................................................................................ii
Safety Precautions................................................................................................................................................iii
Warning & Caution Notes.....................................................................................................................................iv
T.O.C. & MANUAL HISTORY
Table of Contents...............................................................................................................................................v-vi
Revision Sheet........................................................................................................................................................1
NOTES
Operational Condition Notes.................................................................................................................................2
Troubleshooting Notes...........................................................................................................................................3
OPERATIONAL & COMPONENT INFORMATION
Purpose Reference of Main Component Chart...................................................................................................4-6
Additional Component Part Numbers....................................................................................................................6
Sequence of Operation........................................................................................................................................7-9
Modifying Control/Keypad Program Settings.....................................................................................................10
TROUBLESHOOTING
Troubleshooting Flow-Diagram...........................................................................................................................11
Flow-Diagram Reference Troubleshooting Chart..........................................................................................12-14
COMPONENT REMOVAL & INSTALLATION
Location of Electrical Components Picture Overview.........................................................................................15
Electrical Components Removal & Installation.............................................................................................16-20
Cord & Plug Assembly...............................................................................................................
Water Sensor Control Board.......................................................................................................
Water Sensors..............................................................................................................................
Transformer.................................................................................................................................
Temperature (RTD) Probe...........................................................................................................
Control/Keypad Board................................................................................................................
Overtemp Switch (ThermalLimit SW3)......................................................................................
Ignition Module...........................................................................................................................
Time-Delay Relays......................................................................................................................
Chamber Pressure Switch............................................................................................................
Control Relays.............................................................................................................................
Ignitor & Flame Sense Probe......................................................................................................
Door Switch................................................................................................................................
Fuses...........................................................................................................................................
16
16
16
17
17
17
18
18
18
19
19
19
20
20
SP8026-1201 v
TABLE OF CONTENTS
COMPONENT REMOVAL & INSTALLATION (CON’T)
Location of Gas Components Picture Overview..................................................................................................21
Gas Components Removal & Installation......................................................................................................22-24
Power Burner Blower...................................................................................................................
Gas Control Valve.........................................................................................................................
Gas Enrichment Valve..................................................................................................................
Power Burner Blower Pressure Switch........................................................................................
Gas Orice...................................................................................................................................
Location of Gas Burner & Gas Burner Box Picture Overview............................................................................25
Gas Power Burner Removal & Installation......................................[2 PERSONS REQUIRED].......................26
Gas Power Burner Box Removal & Installation..............................[2 PERSONS REQUIRED]..................27-28
Heat Transfer Plate Location Picture Overview...................................................................................................29
Heat Transfer Plate Removal & Installation.....................................[2 PERSONS REQUIRED].................30-31
Heat Transfer Plate Installation Notes & Cautions..............................................................................................32
Miscellaneous Components Removal & Installation.....................................................................................33-34
Auto-Fill Valve............................................................................................................................
Overll (Reed) Switch..........................................................[2 PERSONS REQUIRED]..........
Float Ball (Magnetic)...................................................................................................................
Drain Ball-Valve...................................................................[2 PERSONS REQUIRED]...........
Drip Pan.......................................................................................................................................
Door Components Removal & Installation....................................................................................................35-37
Door Assembly..............................................................................................................................
Inner Door Panel...........................................................................................................................
Door Handle Latch Assembly......................................................................................................
Door Hinge...................................................................................................................................
Door Gasket..................................................................................................................................
22
22
23
23
24
33
33
34
34
34
35
35
36
36
37
SCHEMATIC & CHARTS
Electrical Schematic AT1T-3736 Rev G (S/N 36980 and Below).......................................................................38
Electrical Schematic AT1T-3736 Rev H (S/N 36981 and Above).......................................................................39
Gas Orice Size to Altitude Chart.......................................................................................................................40
Ignitor/Flame Sense Probe Spacing Measurements.............................................................................................41
SP8026-1201 vi
REVISION SHEET
Current Revision: 1201 Prior Revision: N/A
Date: 1/31/12 Date: N/A
Change:
Initial Release.
SP8026-1201 Pg 1
OPERATIONAL CONDITION NOTES
OPERATIONAL CONDITION NOTES
The Water Column (WC) value for the gas pressure being supplied to the steamer •
should be between: Natural Gas = 7” to 10” WC Propane Gas = 11” to 13” WC.
If the supplied gas pressure coming into the steamer is .5 PSI (13.8” WC) or •
higher; an External Gas Regulator is needed in-line, prior to entering the steamer.
If an External Regulator is required, it must be rated at 125% of the BTU/hr rating or
higher.
The micro-Amp (µA) value for the Flame Sense Probe (to ignite the Burner Gas) •
must be at a minimum value of 2.5 µA . (Ignition Module pins FC+ & FC-.) The
Ignition Module will shutdown if value is below .07µA.
AUTO-FILL STEAMER• : The water pressure being supplied to the Auto-Fill Valve
should not be greater than 60 psi.
Measuring Gas Pressure Setup
Manometer
SP8026-1201 Pg 2
TROUBLESHOOTING NOTES
TROUBLESHOOTING NOTES
If the steamer’s gas burner is not igniting, ensure that you have veried and recorded
the following, prior to calling the AccuTemp Service hotline:
With the Gas Burner operating, the Water Column (WC) value of the gas pressure from the •
steamer’s Gas Control Valve is 5” WC = Natural Gas or 10” WC = Propane Gas.
The micro-Amp (µA) value of the Flame Sense Probe (Ignition Module pins FC+ & FC-) should •
have a minimum value of 2.5 µA .
If the steamer is not reaching temperature:
Ensure that the steamer is not in the HOLD Mode verses the COOK Mode. The default mode for •
the steamer, when the PWR button is turned ON, is COOK. So, if the operator presses the Timer
Button then the Cook/Hold button; the operator has just placed the steamer in the HOLD Mode
and the steamer will not reach 212°F (COOK Mode).
Ensure that the steam vent (located on the back of the steamer) is • not blocked or clogged. If the
customer has added an extended exhaust pipe, there’s an increased chance of vent blockage, if
the exhaust pipe is not installed properly. The exhaust pipe should be made of copper, galvanized
or stainless steel. The exhaust pipe should have a diameter of 3/4”; and be sloped 1/4” for every
12” of length (recommend a height no greater than 24”). Also, the addition of extra ttings that
can alter the gravitational ow of the steam condensation, can cause blockage. If vent blockage
does occur, it will cause the chamber pressure switch to stay open; which prevents the heater from
turning back on; and the temperature will continue to drop. Blocked vent can additionally cause
steam to blow out of the door.
Auto-Fill Steamer: If the steamer is overlling with water and causing the steamer to
shut-off:
Ensure the steamer is • level, front to back and side to side. An un-level steamer can cause the
water in the steam chamber to collect in the front of the steamer, causing the Over-Fill Float Ball
to raise and trip the Reed Switch prematurely (every time the steamer is turned ON). Once the
Reed Switch trips, it will cause an Over-Fill Light and Buzzer; while turning off the steamer and
preventing its usage.
Ensure that both of the Water Sensors are clean. Build-up of scale or crud will prevent the Water •
Sensors from providing the appropriate control signals to the Auto-Fill Valve, causing it to overll
with water.
Ensure that the water pressure being supplied to the Auto-Fill Valve should not be greater than •
60 psi. If water pressure is to high, then a larger volume of water will be added to the steam
chamber during the auto-ll cycle; causing the steamer to overll with water.
SP8026-1201 Pg 3
PURPOSE REFERENCE OF MAIN COMPONENTS
Component Part # Purpose
Transformer
Overtemp Switch
(Thermal Limit
SW3)
Control / Keypad
Board
Water Sensor
Control Board
Assembly Part#
AT0A-2779-3
AT1E-2653-4
AT0E-3625-1
AT0E-3230-2
Steps-down the Supply Line Voltage to 24 -28VAC.•
Normally closed switch that provides a safety feature to the machine •
in case the Gas Heater overheats.
If the Gas Heater • overheats, the switch will open and turn the steamer
off; while lighting the red LED Overtemp Light on the Control Panel.
The steamer will • not turn on until the temperature has dropped
enough to allow the Overtemp Switch to close again.
Human interface for steamer operations through push-buttons, •
operations, & display readouts.
Provides power to Control Relay #2 (24VDC).•
Receives input from the Temperature (RTD) Sensor and displays the •
water temperature on the LED readout.
Maintains the preset HOLD temperature.•
Receives inputs from Water Sensor Probes and implements •
corresponding actions for those inputs based on the water level in the
steam chamber.
Controls the Auto-Fill Valve (• if installed) and receives inputs that
provides actions for the desired water level needs.
Water Sensor
Probe
Low Water Level
Probe
High Limit
Water Level
Probe
Auto-Fill Valve
(OPTIONAL)
AT1E-2652-1
AT1A-3841-1
Teon exterior with a stainless steel center that uses the minerals in •
the water to complete the electrical circuit to the Water Board.
MUST BE CLEAN TO WORK PROPERLY.•
Once the Low Water Sensor is satised, it will allow the Ignition •
Module to activate.
If the water level is below the sensor, the Water Board will activate •
the Auto-Fill Valve (if installed) lling the unit the water until the
High Limit Water Sensor is satised.
On initial chamber water ll, once the water level reaches and •
satises the Operational Water Sensor, the Water Board will keep the
Auto-Fill Valve open for 30 additional seconds..
After initial chamber water ll, when the water level drops below the •
sensor’s operational level; the Water Board will open the Auto-Fill
Valve for 30 seconds to raise the water level back above the High
Limit Water Sensor.
This process will repeat as long as the water level stays above the •
Low Water Sensor.
Solenoid Valve that allows water to ow into the steam chamber; that •
is controlled automatically by the Water Board based on inputs from
the Water Sensor Probes.
SP8026-1201 Pg 4
PURPOSE REFERENCE OF MAIN COMPONENTS
Component Part # Purpose
Reed Switch:
Water Over-Fill
Sensor Switch
(OPTIONAL)
Control Relay #1
(AC)
Door Switch AT0A-3660-1
Chamber
Pressure Switch
Time Delay
Relay #1
AT0A-3519-3
Float Ball:
AT0P-3233-1
AT0E-2825-5
S#: 34769 & Up
AT0E-3617-2
S#: 34768 & Lower
AT1A-3847
AT0E-2500-1
Magnetic Reed Switch is used in conjunction with a Float Ball. If the •
water rises too high, the switch opens and turns off the steamer.
When the switch opens, the High Water Overll LED will light. The •
user will have to drain the water out and turn the steamer back ON;
otherwise, the steamer will remain shutdown.
Controls AC Volt input & output signals which provide actions from •
the Water Sensor Board and Auto-Fill Valve (if installed).
Magnetic Switch used to ensure that the door is closed and latched •
prior to generating steam
Ignition Module will • not activate if this switch is not closed (Door
Open).
Normally closed switch that allows pressure to build-up inside the •
steam chamber.
Opens when the steam chamber pressure reaches 1/2 PSI.•
Ignition Module will • not activate if this switch is not closed (Switch
Open).
Normally open switch that closes after 5 seconds (once Door Switch •
& Chamber Pressure Switch are closed) to allow the Ignition Module
to activate and light the Gas Burner.
Control Relay #2
(DC)
Power Burner
Blower
Blower Pressure
Switch
Ignition Module AT0E-3760-1
Ignitor Probe
Flame Sense
Probe
AT0E-2825-6
AT0E-3759-1
AT0E-3617-3
Assembly Part#
AT1E-3795-1
Receives 24VDC (if the safety conditions are met) to the coil •
allowing the Ignition Module to activate the Power Burner Blower.
Provides the correct amount of air into the Gas Burner Box to allow •
the gas from the Gas Burner to ignite and burn efciently.
Closes once air pressure from the Power Burner Fan is applied.•
Ignition Module will • not activate if the switch is not closed (Switch
is Open due to no air from the Blower or the switch is defective).
Receives inputs and provides control signals to the Gas Control Valve •
and Gas Enrichment Valve.
Provides the voltage to the Ignitor Probe to ignite the gas from the •
Gas Power Burner.
Senses the input from the Flame Sense Probe (if there is a ame from •
the Burner or not) and makes appropriate control signal outputs based
if there is a ame from the burner or not.
Uses high voltage, supplied by the Ignition Module, to form a spark •
between the Ignitor Probe and the GND Probe.
Ignites the gas/air mixture from the Gas Power Burner.•
Veries that a ame is present and if no ame is sensed; the Ignition •
Module will go into lockout and deactivates all gas valves.
SP8026-1201 Pg 5
PURPOSE REFERENCE OF MAIN COMPONENTS
Component Part # Purpose
Time Delay
Relay #2
Gas Enrichment
Valve
Gas Control
Valve
Gas Orice
Gas Power
Burner
Gas Power
Burner Box
AT0E-2500-2
AT0P-3818-1
Natural Gas:
AT2E-1806-2
Propane Gas:
AT2E-1806-3
Natural Gas:
AT0B-3758-1
Propane Gas:
AT0B-3758-2
AT1A-3768-1
AT1A-3769-1
Closes for 4 seconds, on initial start-up, to allow the Gas Enrichment •
Valve to open; providing a high concentration of gas to help ignite
poor quality gas on cold start-ups.
Used to provide a richer concentration of gas to the Burner on cold •
start-ups. Helps to compensate for poor quality supplied gas.
Controlled by Time Delay Relay #2 and the Ignition Module.•
Controls and maintains a constant ow of gas to the Gas Power •
Burner.
Controlled by the inputs from the Ignition Module.•
Provides the correct ratio of gas volume and pressure to the burner via •
a preset diameter hole size.
Orice Size for • NG: .1360 & for PG: .0935
Dispenses the mixture of gas and air evenly over its surface to •
provide maximum ame and heat dispersal efciency.
Chamber that positions the Burner and contains the ue gasses •
produced from the bunrer’s ame.
Temperature
(RTD)
Sensor
Door Assembly AT1A-3600-1
Drain Valve AT1P-2239-1
AT0E-3626-1
ADDITIONAL COMPONENT PART NUMBERS
Component Part # Component Part #
Pilot Lamp, 24V Red AT0E-1800-2 Inner Door Assembly AT1A-3647-1
Fuse, Slo-Blo 3A AT0E-2731-1 Door Hinge (Pair) AT1H-2058-3
Ignition Cable AT0E-3810-1 Door Latch Assy, Ceramic Magnet AT1H-3609-1
Provides temperature input to Control/Keypad Board, which displays •
the temperature in the steam chamber based on resistance changes
from the Temperature (RTD) Sensor.
Used to maintain the preset HOLD mode temperature.•
Keeps the steam trapped inside the steam chamber to allow pressure •
to build and cycle the Chamber Pressure Switch.
Manually Open/Close valve used to drain water from the steam •
chamber.
Gasket, Door AT1G-2633-1 Door Latch Mounting Plate AT1M-3046-1
SP8026-1201 Pg 6
SEQUENCE OF OPERATION
MANUAL FILL:
Power Cord Plugged-In & PWR Button Not Pushed
Line Voltage (120/240VAC) comes in through the Terminal Strip and 3A fuse until it reaches •
the Transformer.
Line Voltage is also applied to the Ignition Module on pin L1, after it goes through the 3A •
fuse.
The Transformer steps-down the Line Voltage to 24VAC and applies that, through the •
Overtemp Switch & Overll Reed Switch (Auto-Fill Only), to the Water Sensor Board, the
Control/Keypad Board, and Ignition Module on pin V2.
(The red LED light on the Water Sensor Board will be ashing at a rapid rate.)•
The AC coil of Control Relay #1 (CR#1) is energized.•
PWR Button Pushed & Water Level Is Below the Low Water Level Sensor
PWR Button pushed and the Low Water Light Indicator will be ON and Alarm will sound.•
(The red LED light on the Water Sensor Board will continue to ash at a rapid rate.)•
PRE• is displayed on the Control/Keypad Board.
PWR Button Pushed & Water Is Filled to the Water Level Mark
PWR Button pushed and the Low Water Light Indicator will be OFF and no Alarm will •
sound, due to the Low Water Level Sensor being satised. (The red LED light on the Water
Sensor Board will have a 1 second ash rate.)
Low Water Sensor’s signal will close the Water Sensor Control Board’s K2 Relay, which will •
turn-off the Low Water Light and send a power signal to pin 5 of Control Relay #2 (CR#2),
pin 24VAC of the Ignition Module, and the Gas Control Pilot Valve.
The Control/Keypad Board will send a 24VDC signal to Control Relay #2 closing the DC •
coil (as long as the Door Switch and the Chamber Pressure Switch is closed; allowing the
Time Delay Relay #1 to close after a 5 second delay, which will create a buffer for power to
the DC coil).
Control Relay #2’s DC coil is closed, allowing the power signal from K2 Relay to pass from •
pin 5 to pin 3 of Control Relay #2; sending power to the Ignition Module on pin TH.
(If the Gas Power Burner • does not ignite, the Ignition Module will look-out; and the steamer will have to be turned OFF and back ON to get the steamer to try and re-light the Gas
Power Burner.)
SP8026-1201 Pg 7
SEQUENCE OF OPERATION
MANUAL & AUTO-FILL:
Ignition Module
Power signal to the Ignition Module’s pin TH, activating the Power Burner Fan from pin •
IND on the Ignition Module.
Air pressure from the Power Burner Blower will close the Power Burner Blower Pressure •
Switch, supplying power to pin PSW.
Ignition Module will send control signals from pin V1 to the Time Delay Relay #2, and to •
the Gas Control Main Valve. At the same time, Ignition Voltage is sent to the Ignitor Probe
creating a spark between the probe and GND.
The Time Delay Relay #2 operates for 4 seconds, allowing the Gas Enrichment Valve to •
supply a dense amount of gas (compensation for poor quality source gas), in conjunction
with the Gas Control Valve’ gas.
The Ignition Module will look for a signal from the Flame Sense Probe, via pin S1, to •
indicate taht the gas was lit and burning a ame. If no ame is sensed within 4 seconds of
ignition start, then the Ignition Module will lockout and prevent the steamer from operating.
Gas Power Burner & Heat Transfer
When the Gas Enrichment and Gas Control Valves are opened, gas is sent through the Gas •
Orice and mixed with air from the Power Burner Fan; then it is distributed through the Gas
Burner’s surface ports to be ignited by the Ignitor Probe’s spark.
Flame Sense signal will cause the Ignition Module to keep the Gas Control Valve open, •
supplying gas to the burner. (The ame should be a blue color for maximum efciency.)
The heat generated in the Gas Burner Box will be transferred, by the Heat Transfer Plate, •
evenly over the bottom of the steam chamber; boiling the water inside to create steam for
cooking.
Temperature Sensor (RTD) and Control/Keypad Board
As the temperature rises in the steam chamber, the RTD will provide a signal, based on the •
resistance of heat variance, to the Control/Keypad Board to provide a digital Temp Display.
Control Panel will show • PRE on initial heat-up until the steam chamber reaches 195°F; then
COO will be display between 195°F and 212°F.
The operating default mode on initial power ON is COOK mode; which causes the steamer •
to go to the operating temperature of 212°F.
In HOLD mode; the steamer’s temperature is displayed on the Control Panel until the HOLD •
temperature’s preset value is reached; then HLD is displayed. The Control/Keypad Board
will regulate temperature via the RTD input, based on that HOLD preset value. (This value
can be changed using the program function on the Control/Keyboard Control.)
SP8026-1201 Pg 8
Loading...