Distech Controls RT Series User Manual

2
Theory of operation
The Allure communicating thermostats use a proprietary adaptive
logic algorithm to control the space temperature. This algorithm
controls the heating / air conditioning system to minimize overshoot
while still providing comfort. It provides exceptional accuracy due to
its unique PI time proportioning control algorithm, which virtually
eliminates temperature offset associated with traditional,
differential-based on/off thermostats.
Fig.2 - On/Off mechanical control vs PI electronic control.
Features overview
• 7 day programmable models, 2 or 4 events
• Gas/oil or electric system compatibility for all type of
applications
• Remote indoor averaging sensing capability
• Temperature averaging
• Remote outdoor sensing capability for added flexibility
- System mode lock out
- Heat pump balance point settings
• Remote discharge air sensor input for monitoring purpose
- System efficiency feedback
• Lockable keypads for tamper proofing. No need for thermostat
guards
• Automatic frost protection to prevents costly freeze damage
• Anti short cycle and minimum on/off run time protection.
Reduces wear and maximizes life span of mechanical
equipment.
• 2 programmable digital inputs for added flexibility. Each input
can be programmed as the following:
- None: No function will be associated with the input
- Service: a backlit flashing Service alarm will be displayed on
the thermostat LCD screen when the input is energized. It
can be tied in to the AC unit control card, which provides an
alarm in case of malfunction.
- Filter: a backlit flashing Filter alarm will be displayed on the
thermostat LCD screen when the input is energized. It can be
tied to a differential pressure switch that monitor filters
- Rem NSB: remote NSB timer clock input. Will disable the
internal scheduling of the thermostat. The scheduling will now
be set as per the digital input. The menu part related to
scheduling is disabled and no longer accessible. It provides low
cost setback operation via occupancy sensor or from a dry
contact
- RemOVR: temporary occupancy contact. Disables all override
menu function of the thermostat. . The override function is now
controlled by a manual remote momentarily closed contact.
When configured in this mode, the input operates in a toggle
mode.
With this function enabled it is now possible to toggle between
unoccupied & occupied setpoints for the amount of time set by
parameter (TOccTime) temporary occupancy time.
- Fan lock: used in conjunction with a local air flow sensor
connected to the input. Locks out the thermostat heating and
cooling action and displays a local alarm if no air flow is
detected 10 seconds after the fan ( G terminal ) is energized.
• Programmable smart fan operation saves energy during
night mode
• Non volatile EEPROM memory prevents loss of parameters
during power shortage
• Built in default profile set-up for easier start up and
commissioning
• Configurable SPST output relay on programmable models
for lighting, exhaust fan or fresh air control
• 6 hour typical reserve time for clock in case of power loss
• 0 to 10 Vdc economizer output for more retrofit opportunities
- Built in dry bulb economizer logic using outdoor
temperature sensor
- Input for supply/mixed air temperature sensor
Heat pump model specific features
• Selectable single or dual stage compressor stages
• High balance point:
Locks out auxiliary heating when outside air temperature is
above this value
• Low balance point:
Locks out heat pump compressor operation when outside air
temperature is below this value
• Comfort/economy mode:
In economy mode, heat pump use is maximized before
turning On auxiliary heating
• Compressor/auxiliary interlock:
Adds flexibility by locking out heat pump operation during
auxiliary heating to prevent high pressure trip when the coil
is downstream of the auxiliary heat source.
Fig.2

Distech Controls RT Series Specifications

General

Brand	Distech Controls
Model	RT Series
Category	Thermostat
Language	English