LogiCool InRak™
IT Cooling
20
Introduction
InRak™ Technical Manual 7462807 V1.11.0_04_2016
Controls
Lon BMS Connection
The Airedale controllers, using special serial cards, shall be integrated into LonWorks® networks. The RS485 and the
FTT10 standards shall be supported by the LonWorks® serial cards.
The types of LonWorks® serial cards shall be FTT-10A 78 kbs (TP/FT-10) on the LonWorks® network.
pCOWeb
pCOWeb is a new generation of Airedale supervisory plug-in cards which make communicating with an Airedale unit
simply a matter of logging onto the office Intranet or via the web.
Based on Ethernet TCP/IP secure technology, pCOWeb shall require no proprietary cabling. It shall have little or no set-
up on site and can be pre-programmed with an IP address prior to dispatch from airedale.
BACnet Protocol
The BACnet protocol option shall be supplied either with a pCOWeb (Ethernet) or pCONet (RS485) interface card.
Modbus/Carel BMS Connection
The Airedale controllers shall be able to communicate directly using the Modbus® protocol.
The Modbus® card shall be a small PCB (60mm x 30mm), which can be plugged into the controller to provide it with the
following protocol support
•
Modbus® - JBus slave
• RTU mode (Remote Terminal Unit) with 8 bit encoding and error handling using 16 bit CRC
• Communication standard connection options of RS485 (multipoint) or RS232 (point-point)
•
Maximum Baud Rate of 19200
The data communication shall be asynchronous serial, 8 data bits, 2 stop bits and no parity (in total 11 bits/datum).
The data/parameters from the controller shall be represented within Modbus® registers, each register containing
information pertaining to temperatures, pressures, setpoint, status, etc and is available to the site integration company in
a spreadsheet format
Programming Smart Key
A smart key shall be supplied to offer software back-up of the control strategy. The key shall feature simple plug in
operation and allow transfer of software programs from the key to the microprocessor and vice versa. The use of a
service laptop shall not be necessary.
Expansion Board
An expansion board can be added as an option to add up to 4 additional supply or return air temperature sensors to the
unit. These can be placed on server racks adjacent to the unit to give better regulation over the controlled temperature
and help prevent hot-spots occurring on a server rack or within the room.
Constant Pressure Control (CW units)
Constant pressure control is a method of maintaining a pressure differential between the hot and cold aisles by
modulating the fan speed of the InRak unit.
A -100 to +100Pa differential pressure sensor is used to monitor the pressure difference between the aisles (the same
sensor can be easily changed to -50/+50Pa using a jumper connection depending on individual requirements). This
signal is sent back to the InRak unit microprocessor to modulate the fan speed to maintain a target differential pressure
set point of -10Pa (adjustable). The fan speed modulates to maintain the target differential.
In the event of the differential pressure sensor failing, (open circuit), the unit will revert to the fixed fan speed (as
commissioned). The fixed fan speed can be adjusted in the Manufacturer > Parameters > Evaporator fans menu.
As the pressure difference decreases the fan speed will increase until the pressure difference reaches the set point
again. If the pressure difference was to increase the fans would lower their speed and decrease the pressure difference
back to the set point.
