For proper network cabling is recommended to take the following
precautions:
1.
Do not use different types of cable to achieve the same net
-
work, but always use only the same type of cable;
2.
The network cable carries out safety voltage signals (SELV) and
must not be wired together with dangerous voltage signals
(e.g., 230Vac) or carriers of high currents, especially if in alter-
nating current. Also avoid parallel paths to these power cables;
3.
Wire the cable lying avoiding kinks, narrow bending radii and
unnecessary wrapping in hanks or skeins;
4. Do not twist the cable cord around the power conductors and,
if they should cross, consider an intersection at 90 ° between the
cable and these conductors;
5.
Keep away from sources of electromagnetic field in particular
by large motors, electrical cabinet, reactors for neon, all types
of antennas;
6.
Do not pull the power cable exceeds 110N (11.3kg) to prevent
ironing;
7.
Assess in advance the route so that it will be as short as possible
and note addresses of connected instruments with particular
reference to its location in the orderly sequence. This can be
very useful in maintenance; we recommend to note the Mod
-
bus Address on the product label.
8.
Do not reverse the polarity “+” and “-” of the connection ter
-
minals;
9.
Avoid short lengths of cable terminations in connection tools
to make a maintenance without tearing or flues of the cables
possible;
10.
Identify start and ending terminations and avoid cuts “open”;
Terminating transistors and network polarization
The slew rate control, mutual function in our 485 transceiver and the
limited baud rate to 9600 baud make the terminating resistors not
necessary.
RS485 network needs of polarization typically in charge of the master
device; the controller doesn’t have polarization resistors.
The transceiver used by the controller allows to drive up to 256 points.
RS485 standards require a maximum length of 1200m and/or 32 de-
vices on the network.
It should be noted that more limits are exceeded, higher is the prob-
ability that problems in communication arise. The phenomenon is not
systematic and may not occur. Conversely, in case problems should
arise and none of the points mentioned in this paragraph has solved
them, it is recommended to connect a repeater (CONV RS485-RIP),
as shown in the picture below:
N4177-07
Repeater
G
N
D
+ -
+ -
G
N
D
R=100 - 120 Ohm
Device
Device
G
N
D
+ -
+ -
+ -
G
N
D
G
N
D
Device
G
N
D
+ -
Device
+
-
Supervisory
System
GND
R=100 - 120 Ohm
N.B.: Connect the repeater if cables length exceeds 1200m or if de-
vices are more than 32.
Operation modes
NR9000 works with 3 different operation modes:
•
COMFORT
: the controller will control the temperature (driving
valves and fan) to satisfy the Comfort Temperature Set.
•
ECONOMY: the controller will control the temperature to satisfy
the Economy Temperature Set.
•
FROST PROTECTION: the controller is normally OFF; just during
winter operation it works with a set fixed at 8°C and heating
function only.
CONTROLLER FUNCTIONS
Summer/Winter Changeover
The summer/winter changeover is used by the controller to reverse
the action (Hot/Cold) in 2-pipe systems: the temperature set in
economy mode will be increased with the set correction during sum-
mer and decreased during winter. This information can be defined
through a dedicated digital input or via parameter and it can be set
by the supervisory system or by a configuration tool using MODBUS
protocol.
N.B: by default Summer/Winter changeover is set by local mode; in
plants equipped with a supervisory system it has to be preconfigured
by remote mode;
Initial Valve position
To drive a 3-point actuator is necessary to place the actuator in a
specific position. Each time the controller is powered up, the actua
-
tor will be driven in the closing position for a time equal to the overall
travel time plus 33%.
Cut-off
This function is used to stop the control of the 3 points actuator after
the overall travel time plus 33%. This function is used to ensure the
correct valve closing and to reduce the noise.
The function can be disabled by the supervisory system. In this case
at its stroke end the actuator will be powered indefinitely.
Window contact
This function is used to save energy when a Normally Closed contact
is opened (Open Window). In this case the controller will change
the operation mode from Comfort to Economy. When the window is
open, if the minimum fan speed or the air recirculation functions are
enabled, the fan will be anyway turned off when the set is reached.
Hot/Cold launch
This function is used to avoid the introduction of cold or hot air in the
ambient by delaying (for a set time) the fan start. To disable the
function, set the time = 0.
“Disposal”
The “Disposal” function is useful both for the hot and the cold chan-
nel and it helps to take off the energy stored in the fan coil radiator
by delaying the fan turning off.
To disable the function, set the time = 0.
Minimum speed activation
This function is used to prevent air stratification, especially when using
the Return Sensor, as it could be very low sensitive to temperature
variation that occurs at man’s height. A continuous air movement
helps to avoid /reduce air stratification and to optimize the regula
-
tion.
If the fan is connected to the relay output, it is necessary to set the
“minimum fan speed” parameter at 1. A system configuration with
Proportional Fan requires setting the minimum speed in % of the con
-
trol value (0 - 10V), therefore, if the fan is connected to the 0-10V
output, it is necessary to set the “minimum fan speed” parameter
at a value between 0 and 50. In both cases the 0 value disables the
function. To disable this function, set 0 as minimum speed.
Auxiliary regulation ON/OFF (P action)
This function can be automatically enable when the sensor in posi-
tion S3 is connected. If the remote set in S4 is connected, it is possible
to have a set in the range 10-30°C, otherwise it can be set through
the supervisory system together with the dead zone.
If the supervisory system is not present , this function will be carried on
at fixed point 20°C with dead zone = 1K. The output will be available
in OC2 and it will exclude the management of the electrical coil.
Air recirculation function
This function manages the minimum fan speed. It is enabled setting a
“period” and a “minimum speed” different from zero. When the “pe-
riod” will be passed, the fan will be enabled at the minimum speed
for the time (minutes) set.
1
st
Issue rev. c
12/2015
DBL408e
Page 9
