Welbilt Merco CrispyMax MCG1027NNN Programming manual

CrispyMax™
Crisp and Ready Serving Station
Counter Top and Drop-In
Original Instructions
Installation, Operation and Maintenance Manual
This manual is updated as new information and models are released. Visit our website for the latest manual.
Part Number: MER_IOM_8197863 11/2023
*8197863*
Original Instructions
CAUTION
READ THE INSTRUCTIONS BEFORE USING.
Keep these instructions for future reference.
Serving Quality on Demand

WARNING
Read this manual thoroughly before operating, installing or performing maintenance on the equipment. Failure to follow
instructions in this manual can cause property damage, injury or death.
DANGER
DO not install or operate equipment that has been misused, abused, neglected, damaged, or altered/modified from that
of original manufactured specifications.
DANGER
Keep power cord AWAY from HEATED surfaces. DO NOT immerse power cord or plug in water. DO NOT let power cord hang
over edge of table or counter.
WARNING
Authorized Service Representatives are obligated to follow industry standard safety procedures, including, but not
limited to, local/national regulations for disconnection / lock out / tag out procedures for all utilities including electric,
gas, water and steam.
WARNING
Do Not Store Or Use Gasoline Or Other Flammable Vapors Or Liquids In The Vicinity Of This Or Any Other Appliance. Never use
flammable oil soaked cloths or combustible cleaning solutions, for cleaning.
WARNING
Operation, installation, and servicing of this product may expose you to chemicals/products including [Bisphenol A (BPA),
glass wool or ceramic fibers, and crystalline silica], which is [are] known to the State of California to cause cancer, birth
defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
WARNING
Do not use electrical appliances inside the food storage compartments of the appliance, unless they are of the type
recommended by the manufacturer.
WARNING
Use caution when handling metal surface edges of all equipment.
WARNING
This appliance is not intended for use by children under the age of 16 or persons with reduced physical, sensory or mental
capabilities, or lack of experience and knowledge, unless they have been given supervision concerning use of the appliance by
a person responsible for their safety. Do not allow children to play with this appliance.
WARNING
DO NOT use this product near water – for example, near a kitchen sink, in a wet basement, near a swimming pool, or similar
locations.
NOTE: Proper installation, care and maintenance are essential for maximum performance and trouble-free operation of your
equipment. Visit our website www.mercoproducts.com for manual updates, translations, or contact information for service
agents in your area.
WARNING
DO NOT cover the open top of the CrispyMax while in use as it will void the warranty.
Safety Notices

WARNING
DO NOT line the unit with any material like foil, etc. as it will void the warranty.
WARNING
Use caution when setting up, operating, or cleaning the holding station to avoid contact with heated surfaces.
WARNING
DO NOT attempt to repair or replace any component unless all power to the unit has been disconnected.
CAUTION
The CrispyMax is not suitable for outdoor use. When operating this unit, it must be placed on a horizontal surface.
WARNING
DO NOT use water jets or a steam cleaner to clean this equipment or installed in an area where a water jet can be used.
WARNING
Plug into grounded outlet. DO NOT remove the ground prong from the power cord plug. DO NOT use an extension cord.

Table of Contents
Section 1
General Information
Model Numbers.................................................................................................1-
1
Serial Number Location ................................................................................... 1-
1
Service Personnel..............................................................................................1-
1
Warranty Information ......................................................................................1-
1
Regulatory Certifications .................................................................................1-
1
Section 2
Installation
Location .............................................................................................................2-
1
Weight of Equipment........................................................................................2-
1
Clearance Requirements..................................................................................2-
2
Dimensions ........................................................................................................2-
2
Electrical Service ...............................................................................................2-
2
Voltage.......................................................................................................2-
2
Ground Fault Circuit Interrupter ............................................................2-
2
Rated Amperages, Horsepower, Voltage & Power Cord Chart.............2-
3
Drop-In Installation ..........................................................................................2-
3
Section 3
Operation
Start Up Instructions ........................................................................................3-
1
Section 4
Maintenance
Cleaning and Sanitizing Procedures................................................................4-
1
General ......................................................................................................4-
1
Daily Cleaning Instructions .....................................................................4-
2
Stainless Steel Cleaning ...........................................................................4-
2
Monthly Cleaning Instructions................................................................4-
3
Section 5
Troubleshooting
Troubleshooting Chart ..................................................................................... 5-
1
Sequence Of Operation ....................................................................................5-
1
LED Troubleshooting ........................................................................................5-
1

1-1
Section 1
General Information
Model Numbers
This manual covers standard units only. If you have a custom unit, consult the technical service
department.
Counter Top Drop-In
Model
Model Description
MCG1027NNN
Counter Top (Single Lane)
XMCG1027NNN
Counter Top (Single Lane)(Export)
MCG1827NNN
Counter Top (Double Lane)
XMCG1827NNN
Counter Top (Double Lane)(Export)
MCG2727NNN
Counter Top (Triple Lane)
XMCG2727NNN
Counter Top (Triple Lane)(Export)
MCG3527NNN
Counter Top (Quad Lane)
XMCG3527NNN
Counter Top (Quad Lane) (Export)
Serial Number Location
CrispyMax™ Holding Station serial numbers are located on the data plate that also includes the
model number. The data plate is located on the rear of the unit.
Always have the serial number of your unit available when calling for parts or service.
Service Personnel
All service on Merco equipment must be performed by qualified, certified, licensed, and/or
authorized or service personnel.
Qualified service personnel are those who are familiar with Merco equipment and who have been
authorized by Merco to perform service on the equipment. All authorized service personnel are
required to be equipped with a complete set of service and parts manuals, and to stock a minimum
amount of parts for Merco equipment. A list of Merco Factory Authorized Servicers (FAS’s) is located on
the Merco website at http://www.mercoproducts.com/Service#Service. Failure to use qualified service
personnel will void the Merco warranty on your equipment.
Warranty Information
Visit http://www.mercoproducts.com/Service#Warranty to:
Register your product for warranty,
Verify warranty information,
View and download a copy of your warranty,
Model
Model Description
MCD1228NNN
Drop-In (Single Lane)
XMCD1228NNN
Drop-In (Single Lane)(Export)
MCD2028NNN
Drop-In (Double Lane)
XMCD2028NNN
Drop-In (Double Lane)(Export)
MCD2928NNN
Drop-In (Triple Lane)
XMCD2928NNN
Drop-In (Triple Lane)(Export)
MCD3728NNN
Drop-In (Quad Lane)
XMCD3728NNN
Drop-In (Quad Lane) (Export)

1-2
Regulatory Certifications
Models are certified by:
UL, LLC (Sanitation)
UL, LLC (U.S and Canada)
TUV (U.S and Canada)
CE (Europe)
United Kingdom Conformity Assessed
Shipping Damage Claim Procedure
Your Merco equipment was carefully inspected and packed before leaving the factory. The
transportation company assumes full responsibility for safe delivery upon its acceptance of the
equipment for transport.
What to do if your equipment arrives damaged:
1. File a claim for damages immediately, regardless of the extent of damages.
2. Inspect for and record all visible loss or damage and ensure that this information is noted
on the freight bill or express receipt and is signed by the person making the delivery.
3. Concealed loss or damage that was unnoticed until the equipment was unpacked should
be recorded and reported to the freight company or carrier immediately upon discovery.
A concealed damage claim must be submitted within 5 days of the date of delivery.
Ensure that the shipping container is retained for inspection.
MERCO DOES NOT ASSUME RESPONSIBILITY FOR DAMAGE OR LOSS INCURRED IN TRANSIT

2-1
Section 2
Installation
DANGER
Installation must comply with all applicable fire and health codes in your jurisdiction.
DANGER
Use appropriate safety equipment during installation and servicing.
LOCATION
WARNING
This equipment must be positioned so that the plug is accessible unless other means for
disconnection from the power supply (e.g., circuit breaker or disconnect switch) is provided.
WARNING
Adequate means must be provided to limit the movement of this appliance without depending
on or transmitting stress to the electrical conduit.
WARNING
To avoid instability the installation area must be capable of supporting the combined weight of
the equipment and product. Additionally the equipment must be level side to side and front to
back.
WARNING
This equipment is intended for indoor use only. Do not install or operate this equipment in
outdoor areas.
CAUTION
Do not position the air intake vent near steam or heat exhaust of another appliance.
WARNING
Plug into grounded outlet. DO NOT remove the ground prong from the power cord plug. DO NOT
use an extension cord.
The location selected for the equipment must meet the following criteria. If any of these criteria are not met, select
another location.
•Holding cabinets are intended for indoor use only.
•The location MUST be level, stable and capable of supporting the weight of the equipment.
•The location MUST be free from and clear of combustible materials.
•Equipment MUST be level both front to back and side to side.
•Position the equipment so it will not tip or slide.
•Recommended air temperature is 41° - 86°F (5° - 30°C) .
•Proper air supply for ventilation is REQUIRED AND CRITICAL for safe and efficient operation. Refer to
Clearance Requirements chart on page 2-2.
•Do not obstruct the flow of ventilation air. Make sure the air vents of the equipment are not blocked.
•Do not use under a heat lamp. No external heat source is required for this equipment.

2-2
Weight of Equipment Counter Top Weight of Equipment Drop-In
Model
Shipping Equipment
Weight
MCG1027NNN
40lb/18kg
XMCG1027NNN 40lb/18kg
MCG1827NNN
60lb/27kg
XMCG1827NNN
60lb/27kg
MCG2727NNN
80lb/36kg
XMCG2727NNN 80lb/36kg
MCG3527NNN
100lb/45kg
XMCG3527NNN
100lb/45kg
DANGER
Minimum clearance requirements are the same for noncombustible locations as for combustible
locations. The flooring under the appliance must be made of a noncombustible material.
DANGER
Risk of fire/shock. All minimum clearances must be maintained. Do not obstruct vents or open-
ings.
Counter Top Models Clearance Requirements at Rear Intakes
1.00” (2.54cm)
Do not cover or block the open top of the unit.
Dimensions Counter Top
Model
Width
Depth
Height
MCG1027NNN
10.00”
(254mm)
28.80”
(731mm)
7.80”
(197mm)
XMCG1027NNN
10.00”
(254mm)
28.80”
(731mm)
7.80”
(197mm)
MCG1827NNN
18.50”
(470mm)
28.80”
(731mm)
7.80”
(197mm)
XMCG1827NNN
18.50”
(470mm)
28.80”
(731mm)
7.80”
(197mm)
MCG2727NNN
27.00”
(686mm)
28.80”
(731mm)
7.80”
(197mm)
XMCG2727NNN
27.00”
(686mm)
28.80”
(731mm)
7.80”
(197mm)
MCG3527NNN
35.50”
(902mm)
28.80”
(731mm)
7.80”
(197mm)
XMCG3527NNN
35.50”
(902mm)
28.80”
(731mm)
7.80”
(197mm)
Model
Shipping Equipment
Weight
MCD1228NNN
50lb/23kg
XMCD1228NNN
50lb/23kg
MCD2028NNN
70lb/32kg
XMCD2028NNN
70lb/32kg
MCD2928NNN
90lb/41kg
XMCD2928NNN 90lb/41kg
MCD3728NNN
110lb/50kg
XMCD3728NNN
110lb/50kg
Model
Width
Depth
Height
MCD1228NNN
12.00”
(305mm)
28.0”
(711mm)
8.50”
(216mm)
XMCD1228NNN
12.00”
(305mm)
28.0”
(711mm)
8.50”
(216mm)
MCD2028NNN
20.70”
(526mm)
28.0”
(711mm)
8.50”
(216mm)
XMCD2028NNN
20.70”
(526mm)
28.0”
(711mm)
8.50”
(216mm)
MCD2928NNN
29.00”
(737mm)
28.0”
(711mm)
8.50”
(216mm)
XMCD2928NNN
29.00”
(737mm)
28.0”
(711mm)
8.50”
(216mm)
MCD3728NNN
37.70”
(958mm)
28.0”
(711mm)
8.50”
(216mm)
XMCD3728NNN
37.70”
(958mm)
28.0”
(711mm)
8.50”
(216mm)
Dimensions Drop-In

2-3
Electrical Service
DANGER
Check all wiring connections, including factory terminals, before operation. Connections can be-
come loose during shipment and installation.
WARNING
This appliance must be grounded and all field wiring must conform to all applicable local and na-
tional codes. Refer to rating plate for proper voltage. It is the responsibility of the end user to
provide the disconnect means to satisfy the authority having jurisdiction.
VOLTAGE
All electrical work, including wire routing and grounding, must conform to local, state and national
electrical codes.
The following precautions must be observed:
•The equipment must be grounded.
•A separate fuse/circuit breaker must be provided for each unit.
•A qualified electrician must determine proper wire size dependent upon location, materials used
and length of run (minimum circuit ampacity can be used to help select the wire size).
•The maximum allowable voltage variation is ±10% of the rated voltage at equipment start-up
(when the electrical load is highest).
•Check all green ground screws, cables and wire connections to verify they are tight before start-
up.
GROUND FAULT CIRCUIT INTERRUPTER
Ground Fault Circuit Interrupter (GFCI/GFI) protection is a system that shuts down the electric circuit
(opens it) when it senses an unexpected loss of power, presumably to ground. Merco does not
recommend the use of GFCI/GFI circuit protection to energize our equipment. If code requires the use of
a GFCI/GFI then you must follow the local code. The circuit must be dedicated, sized properly and there
must be a panel GFCI/GFI breaker. We do not recommend the use of GFCI/GFI outlets to energize our
equipment as they are known for more intermittent nuisance trips than panel breakers.
RATED AMPERAGES, VOLTAGE & POWER CORD CHART - COUNTER TOP
Units with plugs are supplied with approximately 6ft (183cm) cords.
Model
V, Hz, Ph
Amps
Watts
Plug Type
MCG1027NNN
120, 60, 1
8.0
980
NEMA 5-15P
XMCG1027NNN
200-240, 50/60, 1
4.4-5.4
890-1275
CEE 7/7
MCG1827NNN
120, 60, 1
15.9
1910
NEMA 5-20P
XMCG1827NNN
200-240, 50/60, 1
8.8-10.6
1768-2530
CEE 7/7
MCG2727NNN
208-240, 60, 1
13.8-15.9
2870-3815
NEMA 6-20P
XMCG2727NNN 200-240, 50/60, 1 13.2-15.9 2655-3815
20A/250V
Pin and Sleeve
MCG3527NNN
208-240, 60, 1
18.4-21.2
3827-5087
NEMA 6-30P
XMCG3527NNN 200-240, 50/60, 1 17.6-21.2 3540-5087
Hubbell C332P6SA
32A/220-240V
Pin & Sleeve

2-4
RATED AMPERAGES, VOLTAGE & POWER CORD CHART - DROP-IN
Units with plugs are supplied with approximately 6ft (183cm) cords.
Model
V, Hz, Ph
Amps
Watts
Plug Type
MCD1228NNN
120, 60, 1
8.0
950
NEMA 5-15P
XMCD1228NNN
200-240, 50/60, 1
4.4-5.4
890-1275
CEE 7/7
MCD2028NNN
120, 60, 1
15.9
1900
NEMA 5-20P
XMCD2028NNN
200-240, 50/60, 1
8.8-10.6
1768-2530
CEE 7/7
MCD2928NNN
208-230, 60, 1
14.4-15.9
2995-3650
NEMA 6-20P
XMCD2928NNN 200-240, 50/60, 1 13.2-15.9 2655-3815
20A/250V
Pin and Sleeve
MCD3728NNN
208-240, 60, 1
18.4-21.2
3827-5087
NEMA 6-30P
XMCD3728NNN 200-240, 60, 1 17.6-21.2 3540-5087
Hubbell C332P6SA
32A/220-240V
Pin & Sleeve
Drop-In Installation
The counter top must be made of a non-combustible material. Verify the location and cutout di-
mensions for the opening in the counter top using the dimensions below.
(X)MCD1228NNN - 10.5x26.0"
(X)MCD2028NNN - 19.0x26.0"
(X)MCD2928NNN - 27.5x26.0"
(X)MCD3728NNN - 36.0x26.0"
Apply a food-grade silicone sealant to the underside of the CrispyMax flange prior to placing the
unit into the opening. Tilt the warmer to allow room for the power cord to enter the opening and
set into place.
Add another thin bead of silicone sealant around the perimeter of the flange once the unit is seat-
ed in place.
Remote switch installation
Remote switch cannot be installed directly in front of CrispyMax drop-in. The cutout must be a
minimum of 1" from the side of CrispyMax unit.
Remote Switch cutout size: 3.3"W x 3.4"H
Feed the end of the remote switch wires through the cutout and plug into the receptacle on the
side of the CrispyMax. The remote switch mounts to the surface through the front of the cutout
with two screws that are provided.

2-5
If the counter is fully enclosed, the provided louver panel(s) MUST be installed behind the
CrispyMax unit adjacent to the louvered back panel on the unit. Failure to do so will void the man-
ufacturer’s warranty.
The attached standoffs may ONLY be removed if the supplemental louver(s) are installed behind
the CrispyMax unit.
Supplemental louver(s) cutout sizes:
Single or Double Lane: 6.25x19.5"
Triple Lane: 6.25x30.5"
Quad Lane 2 cutouts: 6.25x19.5"
The louver panel(s) must be located 2.15" below the counter top surface.
Each louver panel attaches with six screws that are provided.

3-1
Section 3
Operation
DANGER
The on-site supervisor is responsible for ensuring that operators are made aware of the inherent
dangers of operating this equipment.
DANGER
Do not operate any appliance with a damaged cord or plug. All repairs must be performed by a
qualified service company.
DANGER
Never stand on the unit! They are not designed to hold the weight of an adult and may collapse
or tip if misused in this manner.
WARNING
Do not contact moving parts.
WARNING
All covers and access panels must be in place and properly secured, before operating this equip-
ment.
WARNING
Racks, utensils, rack guides, and oven surfaces may become hot during or after use. Use utensils
or protective clothing, like pan grips or dry oven mitts, when necessary to avoid burns.
WARNING
DO NOT use the cavity for storage. DO NOT leave paper products, cooking utensils, or food in the
cavity when not in use.
WARNING
The operator of this equipment is solely responsible for ensuring safe holding temperature levels
for all food items. Failure to do so could result in unsafe food products for customers.
CAUTION
Do not block the supply and return air grills or the air space around the air grills. Keep plastic
wrappings, paper, labels, etc. from being airborne and lodging in the grills. Failure to keep the air
grills clear will result in unsatisfactory operation of the system.
CAUTION
Failure to follow the operating and cleaning instructions could cause grease build-up which may
result in a decrease in food quality.

3-2
NOTE
The airflow and temperature are factory pre-set for optimum holding time for all fried foods. No
adjustment of airflow or temperature is required.
Start Up Instructions
1. Verify that both the crumb tray and food tray are installed properly (see Section 4 for proper
installation).
2. Adjust dividers to desired location. Make sure all tabs of the divider are engaged in the food tray.
3. Turn the power on by pressing the power switch located on the front of the unit in the lower
right corner. The LED above the switch will turn GREEN and blink intermittently while the unit is
heating up to operating temperature.
4. When initially powering up the unit or any time after the power has been disconnected, or after
a power loss, the cabinet will perform a self-test that can last up to 15 minutes. During this time
the fans will cycle at low and high speeds and the heaters will cycle. This will occur on all zones
as well as individual zones/lanes. Once the test is complete, the unit will transition to preheat
and continue normal operation.
5. After approximately 30 minutes the unit should complete its preheat cycle. Once the LED is solid
GREEN it is ready to receive food for holding.

4-1
Section 4
Maintenance
DANGER
All utility connections and fixtures must be maintained in accordance with local and national
codes.
DANGER
It is the responsibility of the equipment owner to perform a personal protective equipment haz-
ard assessment to ensure adequate protection during maintenance procedures.
DANGER
Failure to disconnect the power at the main power supply disconnect could result in serious inju-
ry or death. The power switch DOES NOT disconnect all incoming power.
DANGER
Disconnect electric power at the main power disconnect for all equipment being serviced. Ob-
serve correct polarity of incoming line voltage. Incorrect polarity can lead to erratic operation.
WARNING
All CrispyMax units have a 5-min cool down feature, where after the power switch is turned off,
the fans will run for 5 minutes to help cool down. Never unplug or disconnect the incoming pow-
er before the unit before cool-down is complete as this will bypass an important safety feature
and may cause injury. Always allow unit to cool down prior to disconnecting from power source.
WARNING
Never use a high-pressure water jet for cleaning or hose down or flood interior or exterior of
units with water. Do not use power cleaning equipment, steel wool, scrapers or wire brushes on
stainless steel or painted surfaces.
WARNING
When using cleaning fluids or chemicals, rubber gloves and eye protection (and/or face shield)
must be worn.
WARNING
When cleaning interior and exterior of unit, care should be taken to avoid the front power switch
and the rear power cord. Keep water and/or cleaning solutions away from these parts.
CAUTION
Maintenance and servicing work other than cleaning as described in this manual must be done
by an authorized service personnel.

4-2
CAUTION
Never use an acid based cleaning solution on stainless steel! Many food products have an acidic
content, which can deteriorate the finish. Be sure to clean the stainless steel surfaces of ALL food
products.
Cleaning and Sanitizing Procedures
GENERAL
You are responsible for maintaining the equipment in accordance with the instructions in this manual to
ensure satisfactory performance of your CrispyMax Crisp & Ready Serving Station. Neglecting to follow
these procedures may result in reduced holding times, reduced reliability and may void the warranty.
Maintenance procedures are not covered by the warranty.
Maintenance
Daily
After
Prolonged
Shutdown
At Start-
Up
Dividers, Food
Tray and Crumb
Tray
X
X
X
Interior
X
X
X
Exterior
X
X
X
DAILY CLEANING INSTRUCTIONS
NOTE: Proper daily cleaning MUST be performed. Insufficient cleaning may result in oil seeping
from the safety overflow. This prevents oil from coming in contact with the electronics and
causing damage to the unit.
1. Upon completion of the last holding cycle of the day, allow the unit to cool approximately 30
minutes.
2. Disconnected from power source.
3. Remove divider(s) if present. 4. Remove Food Tray 5. Remove Crumb Tray
6. Wash components with soapy water.
7. Use a soft cloth or sponge, dampened with warm soapy water, to wash the interior and exterior
of the appliance.
NOTE: Do not flood the appliance with cleaning fluid!

4-3
8. Airflow openings should be inspected and any blockage should be removed.
9. Rinse using a cloth dampened with clear water, then dry.
10. Reinstall crumb tray, food tray and divider(s).
11. Ensure the food tray is inserted correctly. The front edge should be flush with the cabinet.
Correct placement of the food tray. Incorrect placement of the food tray. Incorrect placement of the food tray.
Front edge is too high. Food tray is rotated 180˚.
STAINLESS STEEL CLEANING
Stainless steel requires nothing more than a daily wiping with a damp cloth. If, however, an excessive
amount of food particles/grease are allowed to collect, a non-abrasive cleaner (hot sudsy water) may be
used. Merco recommends Merco Degreaser to help remove stubborn, sticky, greasy buildup. Wipe dry
with a clean, soft cloth.
Always rub with the “grain” of the stainless steel to avoid marring the finish. Never use steel wool or
abrasive pads for cleaning. Never use chlorinated, citrus based or abrasive cleaners.
Stainless steel has a clear coating that is stain resistant and easy to clean. Products containing abrasives
will damage the coating and scratch it. Daily cleaning may be followed by an application of stainless
steel cleaner which will eliminate water spotting and fingerprints. Early signs of stainless steel
breakdown are small pits and cracks. If this has begun, clean thoroughly and start to apply stainless
steel cleaners in an attempt to restore the steel.

5-1
Section 5
Troubleshooting
Troubleshooting Chart
Problem
Probable Cause
Corrective Action
Machine doesn’t operate.
No power.
Check power source. Verify voltage.
Call for service.
Excessive time to reach
temperature.
Improper food tray installation /
Blocked airflow at rear of unit
Install food tray properly / Remove
any airflow blockages
Low airflow volume.
Improper food tray installation /
Blocked airflow at rear of unit
Install food tray properly / Remove
any airflow blockages
Airflow works but no heat. Internal wiring. Call for service.
Degrading performance.
Grease or debris build-up.
Clear air intakes at front and rear of
unit.
Unit cycles fans speeds and
heaters.
The unit may be in self-test mode.
When initially powering up the unit
or any time after the power has
been disconnected, or after a
power loss, the cabinet will perform
a self-test that can last up to 15
minutes. During this time the fans
will cycle at low and high speeds
and the heaters will cycle. This will
occur on all zones as well as
individual zones/lanes. Once the
test is complete, the unit will
transition to preheat and continue
normal operation.
Wait at least 15 minutes to see if
self-test mode is complete and the
unit is functioning properly.
Sequence Of Operation
Power Supply
Electrical power is supplied to the unit by a 3 conductor service for single phase.
Black conductor is hot.
White conductor is neutral.
Green and yellow conductor is ground.
Power is permanently supplied to one of the normally open contacts of the main switch
also to one side of the normally open contacts of the main heater relay.
Heating Circuit
Closing the main power switch feeds power through the normally closed high limit
thermostat to the coil of the main relay. Its contacts now close supplying power to the
main heater. Also for air circulation power is supplied to the main fan motor.
This unit has intelligent controls, software and a feedback loop that will automatically adjust for consistent
performance across a range of voltages (110-120V / 200-240V, depending on the model)

5-1
LED Troubleshooting
There is a small round LED above the power switch on the front of the unit that changes color and/or
flashes to alert the user of any performance or service issues.

MERCO
5489 CAMPUS DRIVE, SHREVEPORT, LA 71129
MERCO SALES: 800.221.4583
MERCO SERVICE: 877.392.7770
WWW.MERCOPRODUCTS.COM
[e-mail]
©2023 Welbilt Inc. except where explicitly stated otherwise. All rights reserved. Continuing product improvement may necessitate change of
specifications without notice.
Part Number: MER_IO_8197863 11/2023
Welbilt offers fully-integrated kitchen systems. Welbilt’s portfolio of award-winning
brands includes Cleveland™, Convotherm®, Crystal Tips®, Dean®,Delfield®, Fabristeel®,
Frymaster®, Garland®, Inducs®, Koldtech®, Kolpak®, Lincoln®, McCann’s™, Merco®,
Merrychef®, Multiplex®, RDI®, SerVend™, SunFire®, U.S. Range™, and WMaxx™. Supported
by service brands: FitKitchen®, kitchen systems; and KitchenConnect®, cloud-based open
platform.
Bringing innovation to the table · welbilt.com
Serving Quality on Demand