TEMPERATURE CONTROLLER
N321R
OPERATING MANUAL V1.8x
Man 5001227
Setpoint Adjustment / Voltage indication
The screen voltage measurement. For values lower than 150 Vac and
higher than 254 Vac presents the message 0.
Function available only for model N321R-NTC-LVD.
Temperature adjustment for control OUTPUT 1. SP value is limited to the
values programmed in SPL and SPk in the programming level (Parameter
Configuration, Level 2).
Temperature Unit. Selects display indication for degrees Celsius or
Fahrenheit.
0 Temperature in degrees Celsius. (factory default)
1 Temperature in degrees Fahrenheit.
Sensor Offset - Offset value to be added to the measured temperature to
compensate sensor error.
SP Low Limit - Lower range for SP. SPL must be programmed with a
lower value than spK.
SP High Limit - Upper range for SP. SPx must be greater than spl.
OUTPUT 1 Hysteresis: Defines the differential range between the OUTPUT
1 temperature value at which it is turned off. In degrees.
Off time - Defines the minimum off time for control OUTPUT 1. Once
OUTPUT 1 is turned off, it remains so for at least the time programmed in
oft. This parameter is intended for refrigeration systems where longer
compressor life is desired. Value in seconds, 0 to 999 s.
On time - Defines the minimum on time for control OUTPUT 1. Once turned
on, OUTPUT 1 remains so for at least the time programmed in ont. For
thermocouple inputs this parameter is not available. This parameter is
intended for refrigeration systems where increased compressor life is desired.
For heating systems, program ont to zero. Value in seconds, 0 to 999 s.
Delay time to start control. Upon power-on, control OUTPUT 1 is kept off
until the time programmed in dly is elapsed.
Its usage is intended to prevent multiple compressors to start
simultaneously after the turn-on of a system with several controllers.
Value in seconds, 0 to 250 s.
dib
Defrost
Interval Base
Time base for dfi:
0 Seconds 1 Minutes 2 Hours
Time base for dft:
0 Seconds 1 Minutes 2 Hours
Interval between defrost cycles. Can be selected 0 to 999 seconds/
minutes/hours, according the value specified at dib.
Defrost duration. Can be 1 to 999 seconds / minutes / hours, according the
value specified at dtb.
Hold the temperature indication throughout the defrost interval or the time
defined by this parameter.
0 Do not hold the indication during the defrost;
1 to 250 Time (seconds / minutes / hours) besides the defrost time the
indication will remain held.
The N321R is a controller for cooling applications, with defrost function (forced compressor
shut-down). It accepts NTC, Pt100 and Pt1000 temperature probes, depending on the
product code (the user must observe the measurement range of the selected sensor). The
N321R control output is capable of driving a compressor load of up to 1 HP directly.
The features of a particular model (input sensor type, sensor range, mains supply, etc) are
identified by the label placed on the thermometer body.
SPECIFICATIONS
SENSOR INPUT: The input sensor type can be chosen form the options below (specified
when placing the order):
Thermistor NTC, Type 10 k @ 25 °C; Range: –50 to 120 °C (-58 to 248 ºF);
Accuracy: 0.6 °C;
Sensor interchangeability: 0.75 °C. This error can be compensated by the offset
parameter in the controller.
Pt100; Type: Range: –50 to 300 °C; = 0,00385; 3-wire;
Accuracy: 0.7 °C; IEC-751;
Pt1000; Type: Range: –200 to 530 °C; = 0.00385; 3-wire;
Accuracy: 0.7 °C;
Note: Two 3-meter probe cable are bundled with the instrument. The cable can be extended
up to 200 m.
Measurement Resolution:.............................................................. 0.1 º from –19.9 to 199.9 º
..................................................................................... 1 ºC elsewhere
OUTPUT1: ............................... Relay SPDT; 1 HP 250 Vac / 1/3 HP 125 Vac (16 A Resistive)
........................................................................................ Optionally: Pulse, 5 Vdc, 25 mA max.
POWER SUPPLY: .............................................100 to 240 Vac/dc 10 %
Optionally: ................................................ 12 to 30 Vdc
Mains frequency: .......................................... 50~60 Hz
Power consumption: ............................................. 5 VA
Dimensions: Width x Height x Depth: ............................................ 75 x 33 x 75 mm
Weight: .......................................................................................100 g
Panel cut-out: .................................................................... 70 x 29 mm
ENVIRONMENT: Operating temperature: ........................ 0 to 40 °C (32 to 122 ºF)
Storage temperature: ........................ -20 to 60 °C (-4 to 140 ºF)
Relative humidity: ................................................. 20 to 85 % RH
Case Polycarbonate UL94 V-2
Protection: Box IP42, Frontal panel IP65
Suitable wiring: Up to 4.0 mm²
Serial interface not isolated from input circuitry.
Serial interface isolated from input circuitry, except in 24 V powered model.
ELECTRICAL WIRING
Fig. 01 below shows the controller connections to sensor, mains and outputs.
Fig. 01 - N321R terminals
* The serial communication interface is optional.
Pt100 with 3 conductors: Terminals 11, 12 and 13 must have the same wire resistance for
proper cable length compensation. For 2 wire Pt100, short circuit terminals 11 and 13.
INSTALATION
It is important to follow the recommendations below:
Signal wires should be installed in grounded conduits and away from power or contactor
wires.
The instrument should have its own power supply wires that should not be shared with
electrical motors, coils, contactors, etc.
Installing RC filters (47 R and 100 nF, series combination) is strongly recommended at
contactor coils or any other inductor.
Use protection devices like circuit breakers and fuses.
OPERATION
The controller requires the internal parameters to be configured according to the intended
use for the instrument. The parameters are organized in 4 groups or levels.
Upon power-up, the N323R display shows for 1 second its firmware version. This information
is useful when consulting the factory. Then, the temperature measured by the sensor is
shown on the display. This is the parameter level 0 (temperature measurement level).
To access level 1, press for 1 second until the “SP” message shows up. Pressing
again to go back to level 0.
To access level 2 of parameters, press for 2 seconds until the “uNT” message is shown.
Release the key to remain in this level. Each new pressing on the key will advance
to the next parameter in that level. At the end of the level, the controller returns to the first
level (0).
Level 1 – Setpoint Adjustment
In this level only the Setpoint (SP) parameters are available, alternating the names with their
respective values. Adjust the desired temperature for each setpoint clicking on the and
keys.
Level 2 – Configuration – Parameters Configuration Level
Contains the configuration parameters to be defined by the user, according to the system’s
requirements. Use and keys to set the value. The display alternates the parameter
name and respective value.
Use the and keys to alter a parameter value.
Notes: 1 A parameter configuration is saved when the key is pressed to
advance to the next parameter in the cycle. The configuration is stored in a
non-volatile memory, retaining its value when the controller is de-energized.
2 If no keyboard activity is detected for over 20 seconds, the controller saves
the current parameter value and returns to the measurement level.
Enables compressor protection by voltage monitoring. If the network voltage
is not between the SetPoints (PL and (PK.
0 Disables compressor protection.
1 Enable compressor protection.
Function available only for model N321R-NTC-LVD.
(Pt
Compressor
Protect Time
Determines a delay in the compressor shutting down when compressor
protection's activities by voltage monitoring. Adjustable time interval
between adjustable between 5 to 30 seconds.
Function available only for model N321R-NTC-LVD.
Voltage lower limit used by the compressor protection. Voltage minimum
value that the compressor can operate.
Parameter adjustable between 150 to 254 Vac must be obligatorily 5 Vac
lower than the value set at the higher limit ((PH).
Function available only for model N321R-NTC-LVD.
Voltage lower limit used by the compressor protection. Voltage minimum
value that the compressor can operate.
Parameter adjustable between 150 to 254 Vac must be obligatorily 5 Vac
higher than the value set at the lower limit ((Pl).
Function available only for model N321R-NTC-LVD.
Adress - Controllers with the optional RS485 Modbus RTU communication
interface have the Add parameter at the Configuration level. Set a unique
Modbus address for each equipment connected to the network. Address range
is from 1 to 247.
Password - Enter the correct password to unlock write operations for the
parameters in the following levels.
Calibration low - Offset value of the input. It adjusts the lower
measurement range of the sensor.
Calibration High - Gain calibration. It adjusts the upper measurement
range of the sensor.
Voltage Calibration - Offset adjustment for calibrating the voltage
indication.
Function available only for model N321R-NTC-LVD.
Cold Junction Offset calibration - This parameter is available only for
thermocouple.
Factory Calibration - Restores factory calibration parameters. Change
from 0 to 1 to restore the calibration parameters with factory values.
Protection - Defines the levels of parameters that will be password
protected. See "Configuration Protection" for details.
Password Change - Allows changing the current password to a new one.
Values from 1 to 999 are allowed.
Serial number - First part of the controller electronic serial number.
Serial number - Second part of the controller electronic serial number.
Serial number - Third part of the controller electronic serial number.
Measured temperature exceeded maximum allowed range for the
sensor.
Broken Pt100 or Pt1000. Short circuited NTC sensor.
Measured temperature is below minimum measurement range of the
sensor.
Short circuited Pt100 or Pt1000. Broken NTC.
Level 3 – Calibration Level
The controller is factory calibrated. The following parameters should be accessed only by
experienced personnel. To enter this cycle, the key must be kept pressed for 4 seconds.
Don’t press the and keys if you are not sure of the calibration procedures.
Just press the key a few times until the temperature measurement level is
reached again.
WORKING WITH THE CONTROLLER
The controller turns on and off the compressor output such as to maintain the 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 dfk.
The df1 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 that a defrost cycle be initiated of terminated
immediately. Pressing this key for 1 second will toggle the current defrost status.
CONFIGURATION PROTECTION
A protection system to avoid unwanted changes to the controller parameters is implemented.
The level of protection can be selected from partial to full. The following parameters are part
of the protection system:
Pas: When this parameter is presented, the correct password must be entered to allow
changes of parameters in the following levels.
Prt: Defines the level of parameters that will be password protected:
1 - Only calibration level is protected (factory configuration);
2 - Calibration and Configuration levels are protected;
3 - All levels are protected - Calibration, Configuration and SP.
PA( Parameter for definition of a new password. Since it is located in the calibration
level, can only be changed by a user that knows the current password. Valid
passwords are in the range 1 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 five 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 password for a brand new device is 111.
ERROR MESSAGES
Probe measurement errors force the controller outputs to be turned off. The cause for these
errors may have origin in a bad connection, sensor defect (cable or element) or system
temperature outside the sensor working range. The display signs related to measurement
errors are shown below.
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 turning the compressor off, the driver
passes the signal on your display this occurrence: Toggles the indication of voltage value
measured with the temperature value.
When the voltage exceeds limits (lower than 150 Vac and higher than 254 Vac) is signaling
to indicate temperature alternating with the message 0.
WARRANTY
Warranty conditions are available on our web site www.novusautomation.com.
MASTER PASSWORD
The master password allows user to define a new password for the controller, even if the current
password is unknown. The master password 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 the device with serial number 987123 465 is: 1936
As follows: 1 + sn2= 987; sn1= 123; sn0= 465 = 1 9 3 6
How to use the master password:
1 - Enter the master password value at PaS prompt.
2 - Go to PA( parameter and enter the new password, which must not be zero (0).
3 - Now you can use this new password to access all controller parameters with modify rights.