Ir96: Microprocessor-Based Freezer Controller; New Functions - Carel IR32M Manual

IR96:
MICROPROCESSOR
OR LOW TEMPERATURE RANGE FORCED AIR UNITS
Ir96 is a microprocessor based controller designed for the management of freezer with gravity or forced-air
evaporators. It has 5 relay outputs available to control all the main actuators: compressor (directly up to 1Hp
single-phase), evaporator fans and defrosting. The fourth relay allows remote signalling of any
malfunctioning (high temperature, faulty sensors,...). The fifth relay can be used to control the unit lights or
other auxiliary functions (for example de-misting fans). Two programmable digital inputs allow innovative
performances: automatic alarm management, real time defrosting, management of lights subjected to the
door switch.
IR96 can be supplied directly with 230 Vac (±15%), since it is equipped with an internal transformer (it is
necessary to protect the instrument with a 1 A protection fuse). Ir96 set-point is selectable from -50 to +90 ºC
and temperature can be displayed with a resolution of a tenth of degree from -19.9 to +19.9. It comes
complete with an alarm buzzer and an infrared receiver for remote control programming. It is moreover pre-
arranged for serial card installation which allows to connect the instrument to supervisory and
telemaintenance systems.
Ir96 is an evolution of Infrared Series for commercial refrigeration. Its software has been up-dated
considering all the suggestions of our customers. Following we will see in detail the new functions.

NEW FUNCTIONS

Min-Max temperature data logging
Ir96 allows to record the minimum and the Maximum temperature values read by the ambient sensor during
an interval which can reach up to 199 hours (more than 8 days).
In any moment it is possible to restart the logging period by pushing a button.
Refer to parameters rt, rH, rL next pages.
Defrost duration also 'by time'
The defrost duration can be controlled:
• by temperature, according to the defrost sensor, with a Maximum safety duration. In this case the Ed
alarm (defrost end by time) can be disabled.
• only by time. This is useful on special applications like 'water defrost method'.
Using the defrost by time, the 2nd sensor can monitor the 'air-off' temperature.
It is moreover possible to drive the unit according to a virtual sensor, proportional to both the 'air-on' and
the 'air-off' temperature.
Refer to parameters d0, dP next pages.
Interval between defrosts
On Ir96 the interval between defrosts is constant.
It is calculated starting from the beginning of the defrost cycle.
In this way the defrost duration does not affect the interval between two defrosts.
Refer to parameters dI next pages.
Curtain-switch control
The digital input on Ir96 can be programmed to control the curtain switch.
When the curtain is closed the control automatically increases the set-point of a selectable value.
The light is automatically switched off when the curtain is closed and switched on when it is open.
Refer to parameters A4, A5, r4 next pages.
Evaporator fan management
On normal functioning, the controls of Infrared series can energize the evaporator fan:
• continuously
• only when the compressor is energized
• according to the temperature difference between evaporator and room temperature
Furthermore a special management is possible during defrost and dripping time.
Now on Ir96 a new option is available:
• the evaporator fan can be driven also according to the absolute temperature of the evaporator.
Refer to parameters F0, F1 next pages.
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BASED FREEZER CONTROLLER FOR MEDIUM
53 Cod. +030220151 - Rel. 2.1 - 04/09/98