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
I
CUBE™ Adaptive Defrost sensing technology. This Adaptive
Defrost Control with
I
CUBE™ 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.
