10
5.3 Maintenance Bypass Operation
Use of the bypass key disables the safety features and safe
operation of this instrument. It is imperative that this operation
be performed only after the area has been tested and known to
be safe.
NOTICE
When shipped from the factory the bypass key is shipped on
the strap securing the key cap. Once the commissioning of the
system has been done these should be moved to a known secure
location. It is not advised that they be left on the strap.
To perform some maintenance operations on the CLX-Ex2 it is necessary
to have the entire instrument powered up while the enclosure door is
open. Under these conditions normally the Air Sentinel controller would
determine that the enclosure is not pressurized and power will be removed
to the measurement section of the CLX-Ex2. To allow for this situation, a
special maintenance bypass key is supplied.
Located on the right side of the Air Sentinel controller is a knurled cap.
Removing this cap reveals the key slot. Insert the key, push in slightly
and turn it clockwise to engage the bypass operation. The
TIMER &
BYPASS
lamps will turn RED to indicate the bypass mode. Assuming
the area around the CLX-Ex2 has been tested and known to be safe,
the enclosure door can now be safely opened and power will remain on
to the entire system. The key cannot be removed while operating in the
maintenance bypass mode.
Do not operate the CLX-Ex2 for long periods of time in the bypass
mode. This is intended only for maintenance operations.
Do not operate the CLX-Ex2 in the bypass mode unattended.
To return the instrument to normal, safe operation, close the enclosure
door. Ensure that the air supply is connected turn the key counter-
clockwise and remove. Replace the key cover. If the pressure in the
cabinet has built up to a normal acceptable level, the Air Sentinel will
show all GREEN lamps and the instrument will continue to run.
6.0 Operation
Under normal operation the Air Sentinel controller lamps will all be
GREEN indicating safe operation. If the lamps are not GREEN, correct
this condition first. Please refer to section 5.0 Air Sentinel Controller
Operation.
The CLX-Ex2 Online Chlorine Monitor allows for the measurement of
the chlorine of process water on-line. The chlorine value of the process
water is usually reported in
m
illigrams per
L
iter (mg/L), these units are
equivalent to
P
arts
P
er
M
illion (PPM).
The CLX-Ex2 has two available measurement ranges, 0.00 – 10.00
or 0.00 – 15.00 mg/L (PPM). Although the unit will display above the
range, these readings will not be within the stated accuracy. As the
reagents degrade due to aging, readings above the set range may
decrease in value.
6.1 Routine Measurement
First, ensure that all plumbing and electrical connections are complete
before continuing.
The following steps describe how to measure the value of chlorine of a
sample using this instrument:
1. Apply power to the instrument and allow the unit to warm up. The
instrument may have to re-calibrate the water level sense detector.
This WCAL or water calibration will take few minutes to perform.
2. When a continuous process stream is flowing through the
instrument, the instrument will display the measured chlorine level
of the sample by displaying it on the LCD screen. In addition, the
equivalent signal is provided on the analog (4-20 mA) output, or the
digital (RS-485) output, depending on the options selected.
6.2 Routine Measurement with
Remote Standby
First, ensure that all plumbing and electrical connections are complete
before continuing.
The following steps describe how to measure the value of chlorine of a
sample using this instrument:
1. Apply power to the instrument. The instrument will perform a water
calibration (WCAL). During this time the RSO contact will be closed,
indication the system is busy. This automatic calibration is necessary
and will only be performed once on power up.
2. When the system has completed the WCAL, the RSO contacts will
open indicating that it is in standby mode and is ready to take a
measurement.
3. Application of 24VDC to the RSI+ will initiate a read cycle. The RSO
contacts will close to indicate the system is busy.
4. At the completion of the cycle, the RSO contacts will open and the
measured chlorine level of the sample will be displayed on the LCD
screen. In addition, the equivalent signal is provided on the analog
(4-20 mA) output, or the digital (RS-485) output, depending on the
options selected.
The system is ready to take another measurement.
As mentioned previously the same control can be
performed via Modbus. Setting Coil 00005 to a 1 will start a
cycle. See 4.4.6
Modbus Control.
WARNING
!
WARNING
!
