Intermatic ICUBE Installation And Operation Manual

Spring Grove, Illinois 60081
www.intermatic.com

ICUBE™ Adaptive Defrost Module

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.

• Refer to DTAV40 or DDT40 for additional warnings and installation instructions.
See www.intermatic.com if needed.

• Only use the Intermatic supplied thermistor probe kit. The probe connection(s) to
the DTAV40 and DDT40 control are NOT an isolated Class 2 circuit. Use #18-14
AWG copper conductors for the field supplied wire to the thermistor probe.

• 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.

• This product is only intended to be used with Grässlin™ DTAV40 and DDT40
models.

All trademarks are the property of their respective owners.

NOTICE

PRODUCT DESCRIPTION

The ICUBE™ Adaptive Defrost Module, when added to an existing Grässlin™ DTAV40 - Defrost Control, provides the
DTAV40 Control with the ability to skip scheduled defrost events when they are not needed in order to save energy. Up to
four thermistor probes may be added to the control in order to monitor multiple evaporator coils. Thermistor probes may be
installed up to 400ft (122 m) away from the ICUBE™ module at a remote dedicated or multiplex condensing unit (indoor or
outdoor) or within the freezer/cooler box. No changes to the installed defrost control terminal wiring (such as the wiring for
fans, defrost heater, or thermostat) is required.

To order additional thermistor probe kits (for example, to connect multiple evaporators to one control), use part number
178GR10K-1.

ICUBE™ Adaptive Defrost Module Contents – Part Number DDFM

The kit includes:

• One 10 ft (3.05 m) thermistor probe, with clip

• One 6 ft (1.83 m) input lead

• Four wire connectors

• One dead front

• One ICUBE™ Adaptive Defrost Module, DDFM

• Four #4-40 ¼" screws

FIG. 1 ICUBE™ Module Kit Contents

Specications

Screw

Rated Input:

120/240 VAC, 50 mA, 60 Hz

INSTALLATION

Note: Refer to WARNINGS on page 1 before proceeding.

Tools Required

• Small flathead or #4-40 TORX™ head screwdriver

• Needle nose pliers

• Emery cloth or evaporator cleaner

• Wire cutter

Pre-Installation

1. Disconnect all power to the control at the circuit breaker
or disconnect switch. More than one circuit breaker or
switch may be required to de-energize the control and
all connected loads.

2. Plan 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).

3. The existing control may be installed in an enclosure (as
shown in FIG. 3, for example) or secured via a bracket
inside the condensing unit control panel (as shown in
FIG. 4, for example). The installation of the ICUBE™
module is the same for both instances.

4. If applicable, open the enclosure door.

5. If applicable, remove and discard the existing dead front
cover. See FIG. 2.

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 connections are not an isolated Class 2
circuit.

*Only use a thermistor probe specified for use with DDFM
model.

• Wire stripper

• Fish tape (possibly needed)

• Insulation tape, hose clamp, or wire ties (possibly
needed)

FIG. 2 Existing Dead Front

Install the ICUBE™ Module

1. Remove the FM timer from the control board. SeeFIG. 3 or FIG. 4.

Note: The control board does not need to be removed from the enclosure or the bracket.

FM Timer

Control Board

FIG. 3 Remove the FM Timer (Enclosed Model Shown) FIG. 4 Remove the FM Timer

ICUBE™ Adaptive Defrost Module

2

(Salable item DT-B. See DT-B Installation Instructions.)

Screw

FM Timer

Control Board

Bracket

2. Orient the ICUBE™ module as shown in FIG. 5.

Input Lead

3. Install and fasten the ICUBE™ module to the control

board with the screws provided. Be sure to align the
ICUBE™ module terminals with the terminal fasteners
on the control board when placing. SeeFIG. 5.

Note: Gently tighten screws. Do not over-tighten or

stripping may occur.

4. Install and fasten the FM timer onto the ICUBE™

module with the screws provided. Be sure to align the
FM timer terminals with the terminal fasteners on the

ICUBE™ module. SeeFIG. 5 inset.

Install the Thermistor Probe

1. 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)

FM Timer

Screw

ICUBE™
Module

Control Board

Terminal
Fasteners

Bracket

FIG. 5 Install the ICUBE™ Module (Bracket Shown)

Input Lead Connectors

Note: The field-supplied wires may run along with the

power wires through existing or new conduit.

2. Connect the input lead to the ICUBE™ module as
shown in FIG. 6. The input lead may be inserted into
any of the four connectors on the ICUBE™ module.

Note: Make sure the input pins are properly aligned with

the input lead connector.

3. Route the input lead above the tab and around the
ICUBE™ module as shown in FIG. 7.

4. Cut the input lead to the appropriate length:

– For enclosure installations, cut the input lead length

to ensure the connection is inside the enclosure as
shown in FIG. 7.

– For bracket installations, cut the input lead to an

appropriate length inside the condensing unit control
panel.

5. Use the provided wire connectors to connect the input
lead to the routed 18–14 AWG shielded or unshielded
field-supplied wire.

FIG. 6 Attach the Input Lead

Input Lead

Route Lead over Tab

Wire Connector

ICUBE™ Adaptive Defrost Module

Field-Supplied Wire
to Thermistor Probe

FIG. 7 Route the Input Lead

3

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 could create an insulation barrier which
may cause inaccurate temperature readings.

– Insert the probe between the cooling fins, as shown

in FIG. 8. 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. 9. 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.

Probe

Cooling Fins

FIG. 8 Insert Thermistor Probe between Evaporator Cooling Fins

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 6) 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 field­supplied wire.

9. Use electrical tape to protect all connections against
moisture.

Evaporator Coil

Clip

FIG. 9 Connect Thermistor Probe to Evaporator Coil

10. If additional thermistor probes are needed repeat all
steps in this section. For large evaporators, additional
thermistor probes may be added to a coil on each
(opposite) side.

11. For multiple-evaporator installations, see "Optional:
Multiple Evaporators" on page 6.

ICUBE™ Adaptive Defrost Module

4

System Startup

1. As needed, update your scheduled initiation and
termination times. See DDT40 or DTAV40 instructions
or www.intermatic.com for programming instructions.

2. Snap the provided dead front cover into place, if
applicable. See FIG. 10.

3. Re-apply power to the unit.

4. 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.

5. See TABLE 1 and FIG. 11 or FIG. 12 to verify proper
operation of the ICUBE™ module.

Provided
Dead Front

FIG. 10 Attach the Provided Dead Front

Diagnostics

Mode LED Status Control Mode

Green LED ON Refrigeration mode active

A

Red LED OFF Defrost mode active
Green LED OFF
Red LED OFF

B

Green LED ON
Red LED ON

A/B Blue LED

ON Next scheduled defrost to be

OFF Next scheduled defrost active
1 flash/1 second Calibration mode
5 flashes/

10 seconds
1-4 flashes/

10 seconds

TABLE 1 LED Status Indicator Table

Refrigeration mode active

Defrost mode active

delayed (efficiency mode)

Thermistor sensor error

Only occurs at startup to
indicate the number of sensors
connected to the control

Blue LED

Green LED

Red LED

FIG. 11 LEDs (Enclosed Model Shown)

ICUBE™ Adaptive Defrost Module

Blue LED

Green LED

Red LED

FIG. 12 LEDs

5

ICUBE™ 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 ICUBE™ module operates
solely off of the defrost timer and does not enter efficiency mode.

• Calibration Mode – The ICUBE™ 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 is 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 defrosts within 60
seconds.

Optional: Multiple Evaporators

The ICUBE™ module 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 ICUBE™ module
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 as shown in FIG. 13.

Sensor Wires

FIG. 13 Evaporator System

For additional assistance, contact Technical Services at 1.815.675.7000.

ICUBE™ Module with
Grässlin™ Defrost Timer

Remote Condensing Unit
(Indoor or Outdoor)

ICUBE™ Adaptive Defrost Module

6

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