JTL USER GUIDE
NETWORK REPEATER TYPE:
NR110
15 16 17 18 19 20
AI1
14 13 12 11 10 9 8 7 6 5 4 3 2 1
JNet
Primary
CON3 CON4
JNet Zone
SUPPLY
E L N
E L N
TX
WD
21 22 23 24 25 26 27 28 29
JNET
REPEATER
- +
DISPLAY
MU
S
e
cond
ary
JNe
t
Serial
Port
ETH
AI2
- +
AI3
- +
AI4
- +
AI5
- +
Doc 04258 ISS 1
Electrical Installation Requirements
Care should be taken to separate the power and signal cables to
prevent electrical interference and possible damage due to inadvertent
connection.
The control supply neutral must be connected to terminal 1 for EMC
operation.
CE Conformance
This unit conforms with the relevant EU standards when installed
according to the JTL Installation Requirements for this product
Analogue INPUT
Al1
4-20 mA
Suction Line Pressure
Al2
4-20 mA
Not used
Al3
4-20 mA
Not used
Al4
TP501
Not used
Al5
TP501
Suction Line Pressure
Use of Maintenance Unit
The controller can be checked and the operation adjusted using a JTL
portable maintenance unit which plugs into the controller. Each
item of information has an item number. The more important items
are listed in the tables overleaf.
Examples:
To read item 21 press:
To set item 41 to
&
4.0 press:
To correct errors press:
To select next or previous items press: and
Initial Commissioning and Bitswitch Settings
The controller has a set of data built in to its program for use during
commissioning. These can be accessed by setting item 9 to 1234. This
loads into the unit a suitable set of data. Adjustments should then be
made as necessary.
The unit number for Jnet should be set on item 1.
Function Description
The NR110 act as a bridge, connecting one Jnet subnet to another. All
Jnet messages are passed from one subnet to the other in both
directions. In addition, the NR110 allows suction line pressure data
being broadcast by the JTL Network Controller to be replaced by a
suction line pressure measured by the NR110 itself. Thus, suction line
pressure that is physically local to a group of JTL controllers can be used
for refrigeration control by connecting to the NR110's downstream
subnet.
Suction Pressure Alarms
The NR110 provides for the setting of pressure alarm levels using items
40-42 for information purposes.
Suction Pressure Data
Measured pressure (item 21), Network Controller broadccast pressure
(item 29) and average pressure (item 146) are available together with
calculated Dewpoint (item 142) when the refrigerant type is set (item
157).
Suction Line Temperature
NR110 provides for an optional temperature sensor to be fitted near
the pressure transducer.
Superheat (item 141) and suction temperature (item 31) can be
measured at this location.
Fault Strategies
In the event that the Network Controller is not Communicating on the
primary (Upstream) subnet, the NR110 automatically broadcasts the
suction pressure to all units connected to its secondary (Downstream)
Subnet until primary-side communications is restored.
In the event of a pressure transducer fault at the NR110, the network
repeater will optionally (item 51=1) transmit an error message to the
downstream units, forcing them into their backup strategy (usually 2
temperature operation) or (item 51=0) pass on the suction pressure
being broadcast by the Network Controller.
Alarms
Pressure sensor fault.
Low pressure.
High pressure.
Primary Subnet inactive.
Temperature sensor fault.