8
4.2 Plumbing
The instrument is designed to require very little head pressure to operate,
but will need around 0.34 bar (5 PSI). The maximum pressure for proper
operation should not exceed 10.3 bar (150 PSI). The maximum
allowable fluid temperature is 55°C (131°F).
NOTICE
The fluid waste from drain connection of this instrument contains
reagents diluted with large quantities of sample water. HF scientific
recommends that in the case of ballast installations, the waste
stream is reintroduced to the bilge tanks. This waste fluid must
NEVER be reintroduced into the incoming water stream.
All plumbing connections are intended to be made through stainless
steel connections.
The water sample inlet requires 6 mm OD stainless steel tubing. The
fitting is a compression fitting so the installer need only place the
supplied the nut and feral over tubing and tighten.
The water drain requires 12 mm OD stainless steel tubing. This fitting is
also a compression fitting so the installer need only place the supplied
the nut and feral over tubing and tighten.
Properly installed and sealed connections are required to ensure the
water tightness and ratings of the instrument.
NOTICE
The drain must be open to the Atmosphere for proper operation.
4.3 Air Supply
This instrument requires water and oil free air, (-40°C [-40°F ] Dew
Point, Particles <5u, ISA Grade Hydrocarbon free). The air needs to be
provided at between 5.5 and 7 bar (80-101.5 PSI) with a volume of 4
cubic foot/min as measured at 5.5 bar (80 PSI). This air supply must be
provided continuously from a known safe area. Min flow is 35 SLPM
The air connection requires 6 mm stainless steel tubing. A compression
type fitting is supplied on the base of the main enclosure that simply
requires the installer to slip the supplied nut and feral over the tubing
and then tighten the nut.
4.4 Electrical Connections
All electrical connections must pass through the three compression
grommets on the left side of the instrument. Cabling must be selected
to ensure that these connections are tight. The grommets can accept
cabling from 11 to 21 mm diameter. One grommet is supplied for
system power and two are supplied for low voltage I/O connections.
These grommets must be tightened to maintain cabinet air pressure.
Most of the low voltage electrical communication connections to the
instrument are made at the termination area which is located on the
left side of the instrument. Remove the access cover by loosening the
captive screw. The connections are labeled and are self-descriptive.
Please follow all government recommendations for installation of
electrical connections to and between the instrument and other
peripheral devices.
All terminals are designed to accept wires in the range of 14-28 AWG.
All wires should be stripped to a length of 6 mm (¼").
For line power connections refer to the companion
manual Catalog No. 28749.
4.4.1 RS-485
The RS-485 half-duplex (2-wire) digital interface operates with differential
levels that are not susceptible to electrical interferences. This is why
cable lengths up to 3000 ft can be implemented. The last device on
each bus may require terminating with a 120 ohm resistor
to eliminate signal reflection on the line. Do not run RS-485
cables in the same conduit as power. Set-up of the RS-485
is covered in 8.3
Configuring the RS– 485 Port.
To prevent damage to the instrument,
ensure that power is disconnected
prior to making connections. For ease
of connecting, remove the plug-in
terminal block. Connections are
labeled beside this termination on the
PC board. The recommended cable
is 22 AWG shielded twisted pair. The
grey terminal block is removable to
assist in making connections.
4.4.2 Relay
One relay alarm connections labeled
ALM COM & ALM NO is provided.
Please note that this is a fail- safe so
the “normal” condition is power to the
CLX-Ex2 on and no alarm condition.
The relay is rated 240VAC
2A. Operation of this alarm
is covered in section 8.4
Configuring the Alarm.
4.4.3 4-20 mA
The 4-20 mA output is driven by a 15 VDC power source and can drive
recorder loads up to 600 ohms. Transformer isolation is provided on
the CLX-Ex2.
Do not run 4-20 mA cables in the same conduit as power.
Operation of this output is covered in section 8.1
Setting
the 4-20 mA.
To prevent damage to the instrument, and for general safety
ensure that power is disconnected to the CLX-Ex2 prior to making
any connections. Polarities of the connections are labeled beside this
termination on the PC board.
The recommended cable is 22 AWG shielded twisted pair. To prevent
ground loops, connect the shield at either the CLX-Ex2 or at its
destination, but not both. The grey terminal block is removable to assist
in making connections.
The 4-20mA is factory calibrated. An adjustment is available
on the 4-20mA in sections 8.12 and 8.13. In addition to
making adjustments, these menus output continuous 4 mA
or 20 mA and can be used as a signal test. Remember that
the configuration mode will timeout after 15 minutes.
4.4.4 Remote Standby Connections
The instrument operates on user control software, where an external
control initiates each cycle. This control line is called the RSI short for
Remote Standby Input.
The CLX-Ex2 will indicate the current status on another line called RSO
or Remote Standby Output. These connections are a relay contact that
is closed when busy and open during when in standby mode.
The connections are labeled RSI and RSO. The RSI has + and – polarity
connection associate with it and expects a 24VDC control signal.
The RSO is simply a relay contact and is not polarized.
