Duke HDC3 User manual

Service Manual
DRY CHANNEL
MODELS
HDC3/HDC6
Please read this manual completely before attempting
to install, operate or service this equipment
This document is prepared for trained Duke service technicians. It is not to be used by anyone not
properly qualied to perform these procedures.
This Service Manual is not all encompassing. If you have not been trained on servicing this product,
be sure to read the manual completely before attempting servicing. Be sure all necessary tools, test
equipment, and skills are available. Those procedures for which you do not have the proper skills
and test equipment must be performed only by a qualied Duke trained service technician.
This manual is Copyright © 2013 Duke Manufacturing Company. All rights reserved.
Reproduction without written permission is prohibited. Duke is a registered
trademark of the Duke Manufacturing Company.
Duke Manufacturing Company
2305 N. Broadway
St. Louis, MO 63102
Phone: [phone]
Toll Free: 1-800-735-3853
Fax: [phone]
www.dukemfg.com
P/N 219217C

Service Manual for Dry Channel HDC3/HDC6 Units
2
IMPORTANT WARNING AND SAFETY INFORMATION
WARNING
READ THIS MANUAL THOROUGHLY BEFORE OPERATING, INSTALLING, OR
PERFORMING MAINTENANCE ON THE EQUIPMENT.
WARNING
FAILURE TO FOLLOW INSTRUCTIONS IN THIS MANUAL CAN CAUSE PROPERTY
DAMAGE, INJURY OR DEATH.
WARNING
DO NOT STORE OR USE GASOLINE OR OTHER FLAMMABLE VAPORS OR
LIQUIDS IN THE VICINITY OF THIS OR ANY OTHER APPLIANCE.
WARNING
DO NOT OPERATE THIS EQUIPMENT WITHOUT PROPERLY PLACING AND
SECURING ALL COVER AND ACCESS PANELS.
CAUTION
Observe the following:
•Provide and maintain adequate minimum clearances from all walls and combustible materials.
•Provide and maintain adequate clearance for air openings.
•Keep the equipment area free and clear of combustible material.
• Operateequipmentonlyonthetypeofelectricityindicatedonthespecicationplate.
•Retain this manual for future reference.

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Service Manual for Dry Channel HDC3/HDC6 Units
TABLE OF CONTENTS
IMPORTANT SAFETY INSTRUCTIONS...........................................................................2
INTRODUCTION...............................................................................................................4
GENERAL....................................................................................................................4
MODEL DESIGNATIONS ............................................................................................5
MAIN FEATURES..............................................................................................................6
RELAY BOX.................................................................................................................6
CONTROL DISPLAY ...................................................................................................6
COMPONENT REPLACEMENT .......................................................................................7
TOOLS REQUIRED.....................................................................................................7
CONTROL DISPLAY ...................................................................................................7
CONTROL BOARD OR MYLAR COVER....................................................................7
RELAY BOX.................................................................................................................8
Main Power On/Off Switch ....................................................................................8
Solid State Relays .................................................................................................9
24 Volt Step-Down Transformer ........................................................................... 9
CHANNEL ASSEMBLY..............................................................................................10
TESTING AND TROUBLESHOOTING ........................................................................... 11
COMPONENT TESTING........................................................................................... 11
Primary Power Check.......................................................................................... 11
Fault Conditions................................................................................................... 11
24 Volt Step-Down Transformer ..........................................................................12
Heater Element and Hi-Limit Thermostat ............................................................12
RTD ...........................................................................................................................13
SEQUENCE OF OPERATION ........................................................................................14
TROUBLESHOOTING CHART .......................................................................................15
WIRING DIAGRAM .........................................................................................................16

Service Manual for Dry Channel HDC3/HDC6 Units
4
On/O
Function Control
Button
Select
Buttons
DISPLAYDISPLAY
HEAT ON
READY
GENERAL
The Duke HDC3 Dry Channel unit maintains the
factory set point temperature on 3 channels (front,
back, and center). The Duke HDC6 Dry Channel
unit maintains the factory set point temperature
on 6 channels. Each channel has an A and B
zone. The Main Power On/Off Switch is located
on the Relay/Control Box (herein after referred to
as Relay Box). A display panel will cycle through
the temperature of each channel followed by fault
messages if a fault is detected.
The display temperature will be the average of
the two zones.
INTRODUCTION
Relay
Box
Display
Box
I
DRY CHANNEL TEMPERATURE
PROG
Tub
Main Power
ON/OFF Switch
Channel 3
Zones 3A & 3B
Channel 1
Zones 1A & 1B
Channel 2
Zones 2A & 2B
Figure 1. Dry Channel Major Components
Figure 2. Channels and Zones
Pressing the ON button on the Control Display
activates the display. Pressing the up arrow
will cycle through the six temperature zones,
displaying the actual temperatures. Pressing
the down arrow will cycle through the set point
temperature for each channel. The factory set
point temperature is 275°F. The HEAT ON LED
will indicate an activated relay in any zone. The
READY LED is activated when all zones reach
the set point temperature. A fault message will
be displayed to indicate any zone that does
not reach the set point temperature within 45
minutes of power up.
Figure 3. Control Display

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Service Manual for Dry Channel HDC3/HDC6 Units
MODEL DESIGNATIONS
The following chart lists the different model designations and provides information on the weight and
electrical requirements.
TABLE 1. MODEL SPECIFICATIONS
MODEL NO. SHIPPING WT. ELECTRICAL SPECIFICATIONS
HDC3-37.5-208 160 lbs (59.7 kg) 208VAC, 10.1A, 2100W, 50/60Hz
HDC-37.5-240 160 lbs (59.7 kg) 240VAC 8.8A, 2100W, 50/60Hz
HDC6-37.5-208 315 lbs (117.6 kg) 208VAC, 20.1A, 4200W, 50/60Hz
HDC6-37.5-240 315 lbs (117.6 kg) 240VAC, 17.5A, 4200W, 50/60Hz

Service Manual for Dry Channel HDC3/HDC6 Units
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RELAY BOX
Figure 4. Relay Box
The Main Power On/Off Switch is located on
the lower right side of the Relay Box. This is a
lighted double pull single throw (DPST) switch
rated at 20 Amperes. The Relay Box houses a 24
Volt Step-Down Transformer and six Solid State
Relays (SSR).
CONTROL DISPLAY
Figure 5. Control Display
The display provides a readout of actual
temperature, set point temperature and fault
conditions.
The control board inside the Control Display
maintains the temperature of all three channels.
Each channel has anA& B zone. The control board
monitors each zone’s temperature and activates a
relay to supply power to the heater for that zone.
When the ON/OFF button is pressed, the display
cycles through the temperature of each channel.
If a fault is detected, the fault code is displayed.
The displayed temperature will be the average of
the two zones associated with that channel.
MAIN FEATURES
Main Power
On/Off Switch
I
On/O
Function Control
Button
Select
Buttons
DISPLAYDISPLAY
HEAT ON
READY

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Service Manual for Dry Channel HDC3/HDC6 Units
DRY CHANNEL TEMPERATURE
On/O
Function Control
Button
Select
Buttons
DISPLAYDISPLAY
HEAT ON
READY
WARNING:
BEFORE ANY REPLACEMENT
PROCEDURE BEGINS, THE HDC3/
HDC6 MUST BE ISOLATED FROM
THE POWER SOURCE TO PREVENT
POSSIBLE ELECTRICAL SHOCK.
TOOLS REQUIRED
The only tools required are normal hand-tools.
CONTROL DISPLAY
Figure 6. Control Display
The location of the Control Display will vary by
application and cabinet choice. It is mounted from
the front and is held in place by four screws.
1. Place the Main Power On/Off Switch in the off
position.
2. Disconnect the Dry Channel unit from its
power source. Use proper Lockout/Tagout
procedures.
3. Remove the four screws securing the Control
Display and move it away from mounting
surface.
4. If the Control Display is to be completely
removed, tag and disconnect the wires.
5. Remove Control Display.
6. Reverse the procedure to install Control
Display.
NOTE: The following Control Display component
removal is based on the Control Display having
already been removed from its mounting
surface.
WARNING:
BEFORE ANY REPLACEMENT
PROCEDURE BEGINS, THE HDC3/
HDC6 MUST BE ISOLATED FROM
THE POWER SOURCE TO PREVENT
POSSIBLE ELECTRICAL SHOCK.
CONTROL BOARD OR MYLAR COVER
Figure 7. Exploded View of Control Display
1. With the Control Display removed from its
mounting surface, tag and disconnect wires.
2. Remove the four cover retaining nuts.
COMPONENT REPLACEMENT

Service Manual for Dry Channel HDC3/HDC6 Units
8
POWER
O
ON
OFF
DANGER
3. Remove the Control Board nuts from the four
studs.
4. Reverse the procedure to install a new Control
Board or Mylar Cover.
WARNING
BEFORE ANY REPLACEMENT
PROCEDURE BEGINS, THE HDC3/
HDC6 MUST BE ISOLATED FROM
THE POWER SOURCE TO PREVENT
POSSIBLE ELECTRICAL SHOCK.
RELAY BOX
Figure 8. Relay Box
Typically the Relay Box is mounted on the bottom
of the Dry Channel Tub on the right side. The actual
location may vary based on installation application
orcabinetcongurationused.
1. Place the Main Power On/Off Switch in the off
position.
2. Remove the Dry Channel unit from its
power source. Use proper Lockout/Tagout
procedures.
3. Remove the four screws securing the Relay
Box to its mounting surface.
4. If complete Relay Box is to be replaced, tag
and disconnect wires.
5. Remove Relay Box.
6. Reverse procedure to assemble and install
Relay Box.
WARNING
BEFORE ANY REPLACEMENT
PROCEDURE BEGINS, THE HDC3/
HDC6 MUST BE ISOLATED FROM
THE POWER SOURCE TO PREVENT
POSSIBLE ELECTRICAL SHOCK.
NOTE: The following Relay Box component
removal and replacement assumes the Relay Box
has already been removed from the Dry Channel
unit.
Figure 9. Exploded View of Relay Box

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Service Manual for Dry Channel HDC3/HDC6 Units
Transformer
Solid State Relay
(SSR)
Main Power On/Off Switch
1. Remove the four screws securing the Relay
Box cover. Set the cover aside for reuse.
2. Tag and disconnect the Main Power On/Off
Switch wires.
3. Squeeze the Main Power On/Off Switch
retaining springs and push the switch out
through the front of the box.
4. Reverse this procedure to install a new Main
Power On/Off Switch.
WARNING
BEFORE ANY REPLACEMENT
PROCEDURE BEGINS, THE HDC3/
HDC6 MUST BE ISOLATED FROM
THE POWER SOURCE TO PREVENT
POSSIBLE ELECTRICAL SHOCK.
Solid State Relays (SSR)
Figure 10. View of SSR
1. Using a Multimeter, determine which SSR has
failed.
2. Tag and disconnect the wires from the faulty
SSR.
3. Remove the two screws that attach the SSR
to the board and remove the faulty SSR.
4. Reverse procedure to install a new SSR.
24 Volt Step-Down Transformer
Figure 11. Step-Down Transformer 208/240V
Primary, 24V Secondary
WARNING
BEFORE ANY REPLACEMENT
PROCEDURE BEGINS, THE HDC3/
HDC6 MUST BE ISOLATED FROM
THE POWER SOURCE TO PREVENT
POSSIBLE ELECTRICAL SHOCK.
1. Using a multimeter test the 24 Volt Step-Down
Transformer to determine whether or not it is
the reason for the failure.
2. Tag and disconnect wires from Transformer.
3. Remove four nuts attaching Transformer
to studs on the relay box body and remove
Transformer.
4. Reverse this procedure to install a new
24 Volt Step-Down Transformer.

Service Manual for Dry Channel HDC3/HDC6 Units
10
Center Channel
Screws
End Channels
Center
Channels
Screw
End Channels
CHANNEL ASSEMBLY
A heating zone consists of a Heater Element,
Hi-Limit Thermostat and an RTD. These
components are embedded in a foil wrap that is
attached to the bottom of each ChannelAssembly.
Thefoilwrapisnotserviceableintheeld.The
entire Channel Assembly must be replaced in the
event of a failure.
1. Set the Main Power On/Off Switch to the Off
position.
2. Disconnect the Dry Channel unit from its
power source. Use proper Lockout/Tagout
procedures.
3. Remove six screws (three on each side)
attaching the channel top frame to the tub.
Figure 12. HDC6 Channel Conguration
Figure 13. HDC3 Channel Conguration
4. Carefully lift the ChannelAssembly out, taking
care not to damage wire connections.
5. Tag and disconnect the wires from the foil
wrap on the Channel Assembly to the Control
Board.
6. Reverse this procedure to install a new Dry
Channel Assembly.
NOTE: The End Channels are a different assembly
from the Center Channels. Install the appropriate
channel assembly in its position in the tub.
7. Return the Dry Channel unit to service and
check for proper operation.