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MODBUS
Function
Code
Mapped
Data
Data Map
Range
Read Input
Registers
(0x04)
Process
Variables
8. Alarm Status
If Bit set then alarm is
active:
Bit 0 = Suction
Transducer Failure
Bit 1 = Tout Sensor
Failure
Bit 2 = High Superheat
Bit 3 = Low Superheat
9. System Cycle
Status
If Bit set then mode is
active:
Bit 1 = Setup Mode
Bit 2 = Off Cycle
Bit 3 = Cooling Cycle
Bit 4 = Pump-down Cycle
Bit 5 = Manual Valve
Override Mode
Write Single
Coil (0x05)
Manual
Valve
Control
Bit 0 = Manual Valve
Enabled Flag
0 = Disabled,
1 = Enabled.
The Manual Valve
duration Bit is read-only.
Write Single
Register
(0x06)
Setpoints Same as above.
The max number of
registers written at a
time is
1. The limits can be
seen above in the
‘Read Holding
Register’ definition.
5. Kelvin II Features
5.1. Pumpdown Feature
The Kelvin II will initiate a pumpdown when Auxiliary Tem-
perature sensor terminals are shorted. If desired, this temper-
ature connection could be set up as a dry contact. When a
pumpdown is desired the contact should be closed. The pump-
down will be ended when the short is removed provided that
there are no sensor alarms.
5.2. Manual Valve Position Feature
The Kelvin II has the ability to manually control the valve.
To enable this manual control via the local or remote displays
simply open the setpoint menu and edit the ‘SPoS’ setpoint.
When the value is displayed for this setpoint the user is manu-
ally controlling the valve. The valve position can be changed
by rotating the knob clockwise or counterclockwise. There is
an inactivity timer of 60 minutes while in manual control. The
timer is reset each time the user moves the valve. The manual
control of the valve is ended when the user presses the knob to
go back to displaying ‘SPoS’ or a timeout has been reached.
6. Kelvin II Alarms
The Kelvin II has 4 alarms. The following table lists the
possible alarms and the text that is seen on the controller.
The controller’s alarm status can be viewed via MODBUS,
Network Master, and local and remote displays.
Table 5 Alarms
Alarm Text
Meaning
NoAL
No Alarms active
PSAL
Pressure Sensor alarm
TSAL
Tout Sensor alarm
HSAL
High Superheat alarm
LSAL
Low Superheat alarm
Normally, on the process value screens, the process value
text alternates with its value. When an alarm is activated the
alarm status “-AL-“screen is added to the rotation to make the
user aware that an alarm has been activated. The Alarm Status
menu display item ALS, will show the active alarms shown
in Table 5.
7. Kelvin II Display Networking
The Kelvin II displays can be set up to access other Kelvin II
controllers on the network. The controller’s current ‘CAdr’
value can be determined by pressing down the button on the
display while viewing a process value. To enable the display
network the ‘CAdr’ setting MUST be set to a unique nonzero
value with the RJ-45 connector on the side of the controller
DISCONNECTED.
After ‘CAdr’ has been set, an ‘End’ screen is added just be-
fore the ‘SuPH’ process value. Pressing the button on the
display while viewing the ‘End’ screen brings up a menu al-
lowing the selection of other Kelvin II controllers connected
to the display network. Turning the knob allows the selec-
tion of other Kelvin II controllers based on their appropriate
‘CAdr’ address. The local controller is listed as ‘LocL’ by a
local display. Note: the remote display always includes the
‘End’ screen since it must be able to view any controller on the
display network.
8. Kelvin II Factory Reset
A factory reset can be performed by holding the button down
on the local or remote displays for 5 seconds when power is
first applied. If using a local display the display will show
‘FrSt’ while the factory reset is being performed and then
automatically connect to the local controller.
If using a remote display the display will show ‘FrSt’ and
switch to a menu that allows the selection of the controller
to reset. To perform a factory reset, select the controller with
the appropriate ‘CAdr’ value. The display should show ‘----‘
while the reset is being performed. When finished perform
-
ing factory resets turn the knob counterclockwise until ‘ESC’
is shown on the display. Pressing the button while ‘ESC’ is
shown on the display exits the factory reset menu and should
automatically connect to a controller on the display network.
Table 6 Replacement Parts
Part Number
Description
952560
Kelvin II without display
952561
Kelvin II with local display
952562
Kelvin II Remote panel display
952662
Temperature Sensor Assembly
952795
Well Sensor Kit
953091
Pressure Transducer 150 psig with cable
952995
Pressure Transducer 150 psia with cable
952740
Pressure Transducer 300 psig with cable for
R-410A applications only
952504
Pressure Transducer 500 psig with cable for
R-477 applications only
