NOVUS N321R Temperature Controller, Electronic Thermostats User Manual
- June 5, 2024
- Novus
Table of Contents
NOVUS N321R Temperature Controller, Electronic Thermostats User Manual
N321R is an electronic controller for refrigeration and has features to facilitate the defrost process. It has input for temperature sensors type Pt100 or NTC thermistor and can correct indication errors (Offset). Each type of sensor has a specific temperature measurement range. The controller has a relay-type control output with Common, NO and NC contacts. The characteristics of each controller are identified on the body of the device and according to the purchase order.
SPECIFICATIONS
SENSOR INPUT: The sensor is chosen at the time of purchase and displayed
on the top side of the thermometer case. The options are:
• Thermistor NTC: 10 k @ 25 °C; Range: -50 to 120 °C (-58 to 248 °F);
Accuracy: 0.6 °C (1.1 °F). Maximum error in the interchangeability of original
NTC sensors: 0.75 °C (1.35 °F). This error can be eliminated through the
Offset parameter of the equipment.
Note: For the NTC thermistor option, the sensor is included in the
equipment. Its operating range is limited to -30 to +105 °C (-222 to +221 °F).
It has a 3 m long, 2 x 0.5 mm² cable, which can be extended up to 200 meters.
• Pt100: Range: -50 to 300 °C (-58 to 572 °F); = 0,00385; 3 wires; Accuracy:
0.7 °C (1.3 °F); according to IEC-751 standards.
ELECTRICAL WIRING
The figure below indicates the connection terminals for the sensor, power and controller output and a connection example.
- The serial communication interface is optional.
Pt100 with 3-wire connection. For 2-wire connection, terminals 11 and 13 must be interconnected. For proper cable resistance compensation, the conductors must all have the same electrical resistances (same cross section).
INSTALLATION RECOMMENDATIONS
- Input signal conductors must run through the plant separately from the supply and output conductors. If possible, in grounded conduits.
- All electronic instruments must be powered by a clean mains supply, proper for instrumentation.
- It is recommended to use RC FILTERS (47 and 100 nF, series combination) at contactor coils, solenoids, etc.
OPERATION
Before use, you must configure the controller. To configure it, you must set values for the parameters that determine how the equipment operates. These configuration parameters are organized in groups or levels, called parameter levels:
Notes:
- The programming is saved by the controller when it switches from one parameter to another, and only then is it considered valid. Even in the event of a power outage, the programming is saved in permanent memory.
- If the keys are not used for longer than 20 seconds, the controller returns to the measuring level, finishing and saving the programming done so far.
Level 1 - Setpoint Adjustment
Level 2 - Configuration Level
Displays the sequence of parameters that must be set by the user. The
parameters are shown alternately with their values. To program the desired
value, use the and keys.
Level 3 - Calibration Level
WORKING WITH THE CONTROLLER
The controller turns on the control output to maintain the system temperature
at the selected Setpoint. The front panel display shows the symbol whenever
the compressor is active.
The defrost process of this controller is executed by stopping the compressor.
This procedure is done every time interval defined by the user. The control
output remains off by time also defined by the user. During the defrost
procedure, the temperature indication can be held by adjusting the parameter
dFH.
The dF 1 and dFt parameters define, respectively, the time interval between
defrosts and the duration of the defrost cycle. The controller display shows
the symbol to indicate that a defrost cycle is in progress.
Manual defrost: The key allows you to start or stop the defrost immediately. By pressing this key for 1 second, the controller is forced into defrost. If it is in defrost, it will be forced to end it.
CONFIGURATION PROTECTION
The configuration protection system prevents undue changes to the controller
parameters and, consequently, to its operating mode. This system is composed
of parameters that define the degree of protection adopted (whether total or
only partial). Parameters that define protection:
Pas: Parameter to enter a password to allow changes in the other parameters.
Prt: Parameter to define the level of parameters that will be protected:
1 – Only Calibration level is protected (Default configuration).
2 – Calibration and Configuration levels are protected.
3 – All levels are protected: Calibration, Configuration and SP. PA( Parameter
to change the current password. Valid passwords are in the range 0 to 999.
Configuration protection usage
The PAS parameter is displayed before entering a protected level. If the
correct password is entered, parameters in all following levels can be
changed. If wrong or no password is entered, parameters in the following
levels will be read-only.
Important notes:
1 – After 5 consecutive attempts to enter a wrong password, new tentative will
be blocked for the next 10 minutes. If the current valid password is unknown,
the master password can be used only to define a new password for the
controller.
2 – The equipment leaves the factory with password 111.
MASTER PASSWORD
The master password, which allows you to define a new password for the controller, is based in the serial number of the controller, and calculated as following:
[ 1 ] + [ higher digit of SN2 ] + [ higher digit of SN1 ] + [ higher digit of SN0 ]
For example, the master password for a device with serial number 97123 465 is: 1936
As follows: 1 + sn2= 97; sn1= 123; sn0= 465 = 1 9 3 6
How to use the master password:
1 – In the PaS parameter, enter the master password.
2 – In the PA( parameter, enter a new password, which must not be zero (0).
3 – Use this new password.
ERROR MESSAGES
On the display, the controller shows messages that correspond to problems related to the temperature measurement. Whenever they are displayed, the control output relay is turned off.
COMPRESSOR PROTECTION (N321R-NTC-LVD)
The controller constantly monitors the voltage of power network and shuts the compressor if this tension is not within limits. These limits are defined in parameters (PL and (Pk, adjustable between 150 and 254 Vac. In addition to shutting down the compressor, the controller starts to signal this occurrence on its display: Toggles the indication of voltage value measured with the temperature value. If the voltage is below 150 Vac, it should indicate 0. When it exceeds 254 Vac, it should saturate and indicate 255 Vac.
WARRANTY
Warranty conditions are available on our website www.novusautomation.com/warranty.