Intermatic DDT40 User manual

Spring Grove, Illinois 60081
www.intermatic.com
DDT40 Adaptive Defrost Control
Installation and Operation Manual
SAFETY SECTION
WARNING
Risk of Fire or Electrical Shock
• Disconnect the power at the circuit breaker(s) or disconnect switch(es) before
installing or servicing.
• More than one circuit breaker or disconnect switch may be required to
de-energize the equipment before servicing.
• Installation and/or wiring must be in accordance with the national and local
electrical code requirements.
• For 40 A loads, use #8 AWG wire, for 30 A loads, use #10 AWG rated at least
90º C min. - Use COPPER conductors ONLY.
• Do not exceed maximum current carrying capacity.
• Bonding between conduit connections is not automatic and must be provided as
part of the installation.
• For outdoor locations or wet locations (rain-tight), conduit hubs that comply with
requirements of the UL514B (standard for fitting for conduit and outlet boxes) are
to be used.
• KEEP DOOR CLOSED AT ALL TIMES when not servicing.
• Replace the dead front after servicing or installation, if applicable.
AVERTISSEMENT
Risque d’incendie ou de choc électrique
• Pour les charges de 40 A, utiliser du fil n° 8 AWG, pour les charges de 30 A,
utiliser n° 10 AWG classés 90° C minimum – Utiliser EXCLUSIVEMENT des
conducteurs en CUIVRE.
• La liaison entre les raccordements de conduits n’est pas automatique et doit être
prévue dans le cadre de l’installation.
NOTICE
• Rotate the timer dial clockwise only, rotating counter-clockwise will damage the
timer.
• Do not move the clock hands on the timer. Moving the clock hands manually may
damage the timer.
• The thermistor wire may be extended up to 400 ft (122 m) using field-supplied
wiring between the DDT40 control and the thermistor probe location.
• Use Intermatic model number DT-B for bracket mounting of the defrost controller
board.
PRODUCT DESCRIPTION
The DDT40 Commercial Refrigeration Control is integrated with ICUBE™ Adaptive Defrost sensing technology. This Adaptive
Defrost Control with ICUBE™ technology transforms a typical Grässlin™ DTAV40 Timer into an Adaptive Defrost Control
which has the ability to skip scheduled defrost events when they are not needed in order to save energy. There is absolutely
no change to the Grässlin™ Defrost Timer load wiring. For more details, see the wiring diagrams on page 7.
The thermistor probes can be installed up to 400 ft (122 m) away from the DDT40. Additionally, it can connect up to four
thermistor probes to a single DDT40 control in order to monitor multiple evaporator coils. To order additional thermistor probe
kits, use part number 178GR10K-1.
Used in electric or hot gas defrost applications where the defrost is terminated when the coil is frost free, as sensed by a
temperature or pressure switch, even though the defrost programmed termination time has not been reached. The time
termination functions as a fail-safe and will terminate the defrost if the temperature or pressure switch fails to do so. The
temperature or pressure switch on the refrigeration coil has contacts which close on a temperature or pressure rise above
freezing, indicating that frost and ice have melted from the coil. Typically a wide differential SPDT temperature switch is used
with it’s normally closed contacts wired to the fans thereby delaying the fans from coming on until the coil temperature has
dropped back to below freezing.

2
DDT40 Adaptive Defrost Control
DDT40
FIG. 1 DDT40 with Enclosure FIG. 2 Bracket Mount
(Salable item DT-B. See DT-B Installation Instructions.)
Specications
Operating Voltages
• 120–240 VAC, 60 Hz
Maximum Loads:
Defrost Heater Load:
• 120 VAC: 4800 W
• 240 VAC: 9600 W
Fan and Compressor Load:
• 120 VAC: 1 HP
• 240 VAC: 2 HP
Fan Load on Terminal F:
• 120 VAC: 1 HP
• 240 VAC: 2 HP
Maximum Contact Ratings:
[1] & [3] Contacts:
• 40 A Resistive
• 1 HP @ 120 VAC
• 2 HP @ 240 VAC
[2] & [4] Contacts:
• 40 A Resistive
• 1 HP @ 120 VAC
• 2 HP @ 240 VAC
[1] & [F] Contacts:
• 40 A Resistive
• 1 HP @ 120 VAC
• 2 HP @ 240 VAC
Mounting:
• Enclosure: Type 3R rainproof indoor/outdoor plastic
Wiring Connections:
Note: Refer to WARNINGS on page 1 before proceeding.
• Screw clamp terminals: #22 AWG to #8 AWG wire
• Use #8 AWG wire with 90° C rating for 40 A loads
• Use #10 AWG wire with 90° C rating for 30 A loads
Environmental Ratings:
• Operating temperature: -40° F to 130° F
(-40° C to 55°C)
• Operating humidity: 0-95% RH non-condensing
Thermistor Probe Ratings:
• Thermistor*: Type NTC
• Rating: 10 K Ω @ 25° C
• Wire Size: 24 AWG
• Working Range: -40° F to 152° F (-40° C to 67° C)
• Thermistor probe wire length: 10 ft (3.05 m)
• Connector wire length: 6 ft (1.83 m)
*Thermistor probe connection are not an isolated Class 2
circuit.
*Only use thermistor probe specified for use with DDFM
model.
Agency Approval:
• UL Listed
INSTALLATION
Note: Refer to WARNINGS on page 1 before proceeding.
Tools Required
• Needle nose pliers
• Small flathead or #4-40 TORX™ head screwdriver
• Wire cutter
• Wire stripper
• Emery cloth or evaporator cleaner
• Insulation tape, hose clamp, or wire ties (possibly
needed)
• Fish tape (possibly needed)

3
DDT40 Adaptive Defrost Control
Mount the Enclosure
1. Identify a suitable location for the DDT40 control.
2. Open door and remove dead front by releasing spring
latch on bottom. See FIG. 3.
3. Apply the corresponding terminal identification and door
labels. See the included retrofit kit instructions.
4. If needed, remove the timer mechanism by releasing the
PCB Latch on the bottom. See FIG. 4.
5. Securely mount the enclosure. It is recommended that
you use #10 screws for mounting.
–Place the enclosure in the desired location, providing
space for the enclosure door to open fully. Mount the
enclosure using the provided mounting features. Drill
through the lower mounting holes if they are needed
to secure the enclosure. SeeFIG. 5.
6. Select and open the appropriate number of knockouts
for your installation, as shown in FIG. 6. To remove the
inner 1/2" circle of a knockout, insert a screwdriver in
the slot and carefully punch loose the knockout. If more
space is needed for the wiring, remove the 3/4" outer
ring of the knockout with pliers after removing the inner
circle. Smooth the knockout edges if necessary.
See FIG. 6.
7. Use appropriately rated fittings for installation.
8. Re-install the timer in the enclosure.
9. The dead front will be snapped back into place once
wiring is complete.
Spring Latch
Dead Front
FIG. 3 Remove the Dead Front
PCB Latch
FM Timer
FIG. 4 Remove the FM Timer from the Housing
Mounting
Holes
Enclosure
Mounting
Feature
Back View
FIG. 5 Enclosure
Knockout
FIG. 6 Knockouts

4
DDT40 Adaptive Defrost Control
Wiring
1. Route supply and load wires as appropriate for your installation. Refer to the wiring diagrams on page 7 for examples of
typical installations.
2. Strip the supply and load wires 1/2" from the end.
3. Connect the wires to the proper terminals and tighten them securely.
Install the Thermistor Probe
1. Plan and route the length of field-supplied copper
wire needed to connect the thermistor probe from
the evaporator coil to the input lead. (This wire may
be 18–14 AWG shielded or unshielded up to 400 ft
(121.92m) long).
Note: The field-supplied wires may run along with the
power wires through existing or new conduit.
2. Connect the input lead to the DDT40 control as shown
in FIG. 7. The input lead may be inserted into any of the
four connectors on the DDT40 control.
Note: Make sure the input pins are properly aligned with
the input lead connector.
Input LeadInput Lead Connectors
FIG. 7 Attach the Input Lead
3. Route the input lead above the tab and around the FM
timer as shown in FIG. 8.
4. Cut the input lead length to ensure the connection is
inside the enclosure, as shown in FIG. 8.
5. Use the provided wire connectors to connect the input
lead to the routed field-supplied wire.
6. Connect the thermistor probe to the evaporator coil.
There are two options for probe placement.
Note: Ensure the copper tube surface area designated
for thermistor probe placement is clean. Use Emery
cloth or Evaporator cleaner to clear the surface. A
dirty surface will create an insulation barrier which
may cause inaccurate temperature readings.
–Insert the probe between the cooling fins, as shown
in FIG. 9. Ensure that the probe makes good contact
with one of the evaporator tubes. Then, using needle
nose pliers, carefully bend the cooling fins together
to hold the probe firmly in place.
–Use the provided clip, or if the clip is the incorrect
size, use another means to fasten the thermistor
probe to one of the circuit tubes e.g., hose clamp,
insulation tape, zip tie, as shown in FIG. 10. Clip the
probe onto one of the lower coils in either the
10 o’clock or 2 o’clock position, making sure that
the probe makes good contact with the evaporator
tube.
Wire Connector
Input Lead
Route Lead over Tab
FM Timer
Field-Supplied Wire
to Thermistor Probe
FIG. 8 Route Input Lead
Probe
Cooling Fins
FIG. 9 Insert Thermistor Probe between Evaporator Cooling Fins

5
DDT40 Adaptive Defrost Control
Recommended Thermistor Probe Position
The probe should be positioned and fastened wherever
frost accumulates most quickly. This is generally 1" to 2"
(2.5 cm to 5 cm) from either end, at the bottom quarter
and at the discharge side of the evaporator coil. If there
is uncertainty about where frost typically accumulates
the fastest, put the system into a manual defrost (see
"Optional: Manual Defrost" on page 10) and monitor
the last area of the evaporator where frost is present
prior to a completely frost-free coil.
Make sure the probe is not fastened in close proximity
to the electric defrost heating element.
7. Route the thermistor probe wires away from the
evaporator fans and cooling fins, avoiding pinches
and strain. Route the wire through existing or new line
voltage conduits. Secure the wires as appropriate for
your installation.
8. Use the provided wire connectors to connect the
thermistor probe wire to the routed 18–14 AWG field-
supplied wire.
9. Use electrical tape to protect all connections against
moisture.
10. If additional thermistor probes are needed repeat all
steps in this section. For large evaporators, you can
add a thermistor probe to a coil on each (opposite) side.
11. For multiple-evaporator installations, see "Optional:
Multiple Evaporators" on page 10.
Evaporator Coil
Clip
FIG. 10 Connect Thermistor Probe to Evaporator Coil
Mode Selection
Determine which defrost control (Grässlin™ or other manufacturer) will be replaced as indicated in TABLE 1. The mode
selector DIP switch (located at the lower right side of the board) determines the configuration of terminals 2 and 4. In position
“A”, the terminals are normally closed, and will open during a defrost. In position “B”, terminals 2 and 4 are normally open,
and will close during a defrost. Select the proper position from the table and wiring diagrams indicated. To select mode simply
slide the switch as follows:
• Mode A - position switch up;
• Mode B - position switch down;
In most applications, the contacts at terminals 2 and 4 are
normally closed with S1 in the “A” position and control the
fans and refrigeration equipment or compressor. For hot gas
defrost, or for double-pole switching, contacts 2 and 4 may
be configured as normally open by selecting mode “B”. Refer
to wiring diagrams 1 through 10 for additional details.
Note: When Mode “B” is selected the DDT40 will operate as follows:
–Refrigeration Mode - Red and Green LEDs will turn OFF (terminals 1 and 3, 2 and 4 will be open while terminals 1
and F will be closed).
–Defrost Mode - Red and green LEDs will turn ON (1 and 3, 2 and 4 will be closed while 1 and F will be open).

6
DDT40 Adaptive Defrost Control
Trippers are “IN”
Indicates
Refrigeration
“Green”
LED ON
DDT40 TRIPPERS
MODE A
In Refrigeration Mode
Arrow on timer points to current time.
Note: It is necessary to apply power across terminals 1&N in order to perform electrical test.
DDT40 TRIPPERS
MODE B
In Refrigeration Mode
Arrow on timer points to current time.
In Defrost Mode
Arrow on timer points to current time.
Trippers are
“OUT”
Indicates
Defrost
“Red”
LED ON
L1 L2/N
F31 2 4X
N
“1 & F” Make
“1 & 3” Break “2 & 4” Make
CONTROL
POWER
TERMINATE
INPUT
L1 L2/N
F31 2 4X
N
“1 & F” Break
“1 & 3” Make “2 & 4” Break
CONTROL
POWER
TERMINATE
INPUT
Trippers are “IN”
Indicates
Refrigeration
Both LED’s
OFF
In Defrost Mode
Arrow on timer points to current time.
Trippers are
“OUT”
Indicates
Defrost
Both LED’s
ON
L1 L2/N
F31 2 4X
N
“1 & F” Make
“1 & 3” Break “2 & 4” Break
CONTROL
POWER
TERMINATE
INPUT
L1 L2/N
F31 2 4X
N
“1 & F” Break
“1 & 3” Make “2 & 4” Make
CONTROL
POWER
TERMINATE
INPUT
Note: Although wiring is equivalent, the DDT40 will not fit inside of a Paragon Enclosure. This enclosure will need to be
changed out with the provided Grasslin™ Enclosure.
Paragon Precision Grässlin™Mode
Selection
Terminal Ident.
Label
Wiring
Diagram Terminal Layout
TIME INITIATED, TIME TERMINATED
8045®6045 DDT40 A 8045 5
F3
1-N
2
4X
8041®6041 DDT40 A 8041 2
N1X
324
8047®6047 DDT40 B 8047 4
N13422
TIME INITIATED, REMOTE TEMPERATURE OR PRESSURE TERMINATED
8145®6415 DDT40 A None 1, 6
F3124NX
8141®6141 DDT40 A 8141 7
N13
2
4X
8143®--- DDT40 B 8143 8, 9
1N
3
42
X
TIME INITIATED, PRESSURE TERMINATED
(Separate Presure Switch Required (see instructions))
8245®--- DDT40 A 8245 10
F3
1-N
24
Xp
p
8247®--- DDT40 B 8247 3
N1324
Xp
p
Cross Ref.
DDT40 replaces over 40 models
TABLE 1 Defrost Control Replacement Selector

7
DDT40 Adaptive Defrost Control
8141 Replacement
Mode A with 8141
Terminal Block Label Applied
7
L1
L2
TERMINATION
THERMOSTAT
W/FAN DELAY
2
4X
N
8143 Replacement
Mode B with 8143
Terminal Block Label Applied
8
8143
LABEL
LINE
CONNECT ACROSS
COMPRESSOR
THERMOSTAT
FANHOT
GAS
VALVE
13
L1
L2
TERMINATION
THERMOSTAT
2X
8143 Replacement–Double Pole Switching
Mode B with 8143 Terminal Block Label Applied
9
8143
LABEL
3
DEFROST
HEATER
LINE
SOLENOID
VALV E
OR
CONTACTOR
14
N
TYPICAL WIRING DIAGRAMS
All switch positions are shown in refrigeration cycle operation, and change position upon initiation of a defrost.
1
THERMOSTAT
COMPRESSOR
OR
SOLENOID VALVE
OR
CONTACTOR COIL
DEFROST
HEATER
L1
L2
124 X
8041 Replacement
Mode A with 8041
Terminal Block Label Applied
2
8041
LABEL
3
LINE
FAN
N
3
L1
L2
22
8047 Replacement–Double Pole Switching
Mode B with 8047
Terminal Block Label Applied
4
8047
LABEL
3
DEFROST
HEATER
LINE
SOLENOID
VALV E
OR
CONTACTOR
N4
1
8245 Replacement
Mode A with 8245
Terminal Block Label Applied
10
THERMOSTAT
COMPRESSOR
OR
SOLENOID VALVE
OR
CONTACTOR COIL
DEFROST
HEATER
L1
L2
TERMINATION
THERMOSTAT
W/FAN DELAY
12X8141 LABEL
3
LINE
FAN
N4
COMPRESSOR
OR
SOLENOID VALVE
OR
CONTACTOR COIL
FAN
MOTOR
DEFROST
HEATER
L1
L2
PRESSURE
SWITCH
F3
1-N
24
LINE
THERMOSTAT
Xp
p
LABEL
8245
COMPRESSOR
OR
SOLENOID VALVE
OR
CONTACTOR COIL
FAN
MOTOR
DEFROST
HEATER
L1
L2
TERMINATION
THERMOSTAT
W/FAN DELAY
F3124X
N
LINE
8145 Replacement
Mode A - No Label Required
5
THERMOSTAT
DEFAULT (Out of the Box)
CONTROL
POWER
TERMINATE
INPUT
CONTROL
POWER
TERMINATE
INPUT
CONTROL
POWER
TERMINATE
INPUT
CONTROL
POWER
TERMINATE
INPUT
CONTROL
POWER
TERMINATE
INPUT
CONTROL
POWER
TERMINATE
INPUT
CONTROL
POWER
TERMINATE
INPUT
L1
L2
4
8247 Replacement–Double Pole Switching
Mode B with 8247 Terminal Block Label Applied
8247
LABEL
3
DEFROST
HEATER
LINE
SOLENOID
VALV E
OR
CONTACTOR
N2
1p
PRESSURE
SWITCH
Xp
8045 Replacement
Mode A with 8045
Terminal Block Label Applied
COMPRESSOR
OR
SOLENOID VALVE
OR
CONTACTOR COIL
FAN
MOTOR
DEFROST
HEATER
L1
L2
F3
1-N
24 X
LINE
THERMOSTAT
8045
LABEL
CONTROL
POWER
TERMINATE
INPUT
THERMOSTAT
COMPRESSOR
OR
SOLENOID VALVE
OR
CONTACTOR COIL
DEFROST
HEATER
L1
N
TERMINATION
THERMOSTAT
W/FAN
124X
120V Fan & Defrost Heater; 240V Compressor
Mode A - No Label Required
6
3N F
FAN
120V
240V
L2
DELAY
CONTROL
POWER
TERMINATE
INPUT
All trademarks are the property of their respective owners.

8
DDT40 Adaptive Defrost Control
Replacing Existing Defrost Timers
Terminal Identication
The standard DTAV40 terminal identification is identical to the Paragon 8145 with the addition of the “F” terminal. Terminal
identification labels are provided for the other models to be placed over the printed numbers on the printed circuit board.
From Table 1, select the proper label, apply to the printed circuit board and wire per the original wiring or the wiring diagrams
indicated.
“F” Terminal
The DTAV40 contains a normally closed contact between terminals 1 and F. This terminal may be used to switch the fans off
during a defrost rather than terminals 2 and 4. For hot gas defrost applications, with the mode switch set to position “B”, the
fans may be connected to terminal “F”.
8143 Replacement
When replacing a Paragon 8143, wire the termination thermostat to terminal X of the DTAV40 (with the 8143 label attached),
and the adjacent blank terminal. The Paragon timers are wired to terminal X and the blank terminal. If the termination
thermostat is wired to terminal N of the DTAV40 temperature, termination will not occur and may result in burnout of the
DTAV40. See Wiring Diagrams 8 and 9.
8240 Series Replacement
The DTAV40 may be used to replace the Paragon 8240 Series Defrost Timers with integral pressure termination by the
addition of a remote pressure switch wired to terminals Xp and p of the DTAV40 (with an 8240 series terminal label applied).
There must be no external voltage connected to the pressure switch. Set the pressure switch cut-in to the same value as set
on the Paragon defrost timer being replaced. Set cut-out 6 to 14 psi below cut-in. See the wiring diagram
Programming
Setting the Time
Rotate the FM timer dial clockwise until the time of day (AM or PM) of the outer dial is aligned with the triangle marker on the
inner dial.
Note: The AM and PM locations on the dial represent 6 AM and 6 PM. For example, if the triangle points to the 7 after PM,
then the current time is 7 PM. If the triangle points to the 5 before PM, then the current time is 5 AM.
NOTICE
Do not rotate dial or minute hand counter-clockwise.
Follow this procedure to configure defrost times:
1. On the timer wheel, choose a defrost starting time.
2. Slide the tripper upward that is directly above the
desired time. The timer will initiate a 15 minute defrost
at the configured time.
3. To increase the duration of the defrost, slide up the trippers that are adjacent to the starting time.
Note: Each tripper on the time wheel represents 15 minutes. For example, to set a 45 minute defrost, slide the two trippers
adjacent to the starting time.
Note: The AM and PM locations on the wheel represent 6 AM and 6 PM.
4. Repeat steps 1 through 3 as necessary to configure multiple defrost times for a given day.
Defrost Duration:
The defrost duration is settable in 15 minute intervals from a minimum of 15 minutes up to several hours. The defrost duration
determines the termination time. In standard configuration, the contacts between terminals 1 and 3 are normally open and
closed during a defrost to energize defrost heaters; the contacts between terminals 2 and 4 are normally closed with S1 in “A”
position and open during a defrost to de-energize refrigeration and fans.

9
DDT40 Adaptive Defrost Control
Setting Maximum Defrost Duration:
Different defrost durations may be set for each defrost initiation setting. Each white tab (tripper) provides a 15 minute interval.
For longer defrost duration, move additional tabs (following in time) from the initiation tab. For example, if a 45 minute defrost
is to start at 7:00 AM, move the tab outward that lies between 7:00 and 7:15 on the AM side of the dial, and the tabs
adjacent to 7:15-7:30 and 7:30-7:45. (3 tabs moved outward). The defrost will initiate at 7:00 AM and time terminate at 7:45
AM (if temperature termination does not occur first).
IMPORTANT INFORMATION: The Normally Closed contacts between terminals 2 and 4 are only closed when
the defrost timer is energized. The 2-4 contacts are the Normally Open contacts of relay K2. When checking
continuity of the control with no voltage applied, the 2-4 contacts will appear as open; this is normal. The 1-3
contacts will appear as open and the 1-F contacts will appear as closed. We recommend that the control be
tested by using a voltmeter, with rated voltage applied.
System Startup
1. Snap the provided dead front cover into place, if
applicable. See FIG. 11.
2. Re-apply power to the unit.
3. The control will sense the number of probes connected.
Note: Observe the blue LED during startup in order to
verify that the ICUBE™ module registers the correct
number of thermistor probes. The blue LED will flash
once for each recognized probe.
Dead Front
FIG. 11 Attach the Dead Front
4. See TABLE 2 and FIG. 12 or FIG. 13 to verify proper
operation of the DDT40 control.
Diagnostics
Mode LED Status Control Mode
AGreen LED ON Refrigeration mode active
Red LED OFF Defrost mode active
B
Green LED OFF Refrigeration mode active
Red LED OFF
Green LED ON Defrost mode active
Red LED ON
A/B Blue LED
ON Next scheduled defrost to be
delayed (efficiency mode)
OFF Next scheduled defrost active
1 flash/1 second Calibration mode
5 flashes/
10 seconds Thermistor sensor error
1-4 flashes/
10 seconds Only occurs at startup to indicate the number of sensors
connected to the control
TABLE 2 LED Status Indicator Table
Blue LED
Green LED
Red LED
FIG. 12 LEDs (Enclosed Model Shown)
Blue LED
Green LED
Red LED
FIG. 13 LEDs

10
DDT40 Adaptive Defrost Control
DDT40 CONTROL FUNCTIONALITY
Modes
• Efciency Mode – Scheduled Defrosts are bypassed when the control is in this state. This is indicated when the blue
LED is ON continuously. If there is no thermistor probe attached or a probe failure occurs, the DDT40 control module
operates solely off of the defrost timer and does not enter efficiency mode.
• Calibration Mode – The DDT40 control module enters calibration mode after the first Scheduled Defrost and after each
allowed defrost cycle. During calibration the control establishes a baseline coil behavior.
• Thermistor Probe Initialization – The number of thermistor probes connected to the control is detected during the
initial startup of the system. The blue LED flashes the number of times equal to the number of probes detected. If the
correct number of probes are not detected, disconnect power to the control before you attempt to correct the problem.
Optional: Manual Defrost
To initiate a manual defrost, rotate the FM timer dial clockwise through two consecutive scheduled defrost cycles within 60
seconds.
Optional: Multiple Evaporators
The DDT40 control has four sensor inputs that can monitor up to four evaporator coils. Typically, in a four-evaporator system,
the timer activates a contactor that energizes the multiple defrost loads simultaneously. When the DDT40 control senses
a decrease in capacity in one or more coils, efficiency mode shuts off and the defrost timer initiates a defrost at the next
scheduled interval.
Sensor Wires
DDT40 with
ICUBE™ Technology
Remote Condensing Unit
(Indoor or Outdoor)
FIG. 14 Evaporator System
For additional assistance, contact Technical Services at 1.815.675.7000.
©2016 Intermatic