3 OPERATION
3.1 Overview
ChlorGuard provides an automatic emergency isolation system for chlorine cylinders and drums.
Operation of the system is initiated by an integral PLC and a Chlorine Sensor/Transmitter local to the
chlorine container. Further means of initiation can be by remote manual push buttons and trip inputs
from the user’s process.
3.1.1 Power Supply
Power supply to the ChlorGuard7 is a standard 240V mains power plug and pin cable arrangement.
3.1.2 Battery Back-Up
Power backup consists of a pair of sealed lead acid batteries that provides 24V back-up power for a
minimum of 4 hours under load and 24 hours in Stand-By.
3.1.3 PLC Programmable Logic Controller
The touch screen PLC contains all the menus and control functions for the ChlorGuard7 system. The
program logic is fixed by Orica and cannot be tampered without Orica’s approval and access
password. Menus can be accessed by touching the screen and following the instructions on the
screen. A full description of the PLC menus is outlined in Appendix A.
3.1.4 DC (UPS) power supply
The DC Uninterrupted Power Supply (UPS) provides reliable 24 VDC Power Supply load to the
ChlorGuard system. If there is AC input, it will provide power supply for the load and at the same time
recharge the chargeable battery. If there is no AC input, the battery will provide power supply to the
load. There is a management circuit for the chargeable battery inside (including charging constant
current circuit, battery protection, battery discharge control and automatic battery swift transfer
circuit).
3.1.5 Chlorine Sensor/Transmitter
Orica have chosen the Drager Polytron 7000 Chlorine Sensor/Transmitter which has a SIL2
certification (Safety Integrity Level). This provides an assurance of 99.9% reliability on the sensor and
transmitter provided the system is calibrated as instructed. The transmitter transfers the signal from
the chlorine sensor to the ChlorGuard PLC which in turn activates the actuators on the chlorine
contains to close. The Polytron 7000 transmitter also displays the level of chlorine via a digital
display. Up to 2 chlorine sensors can be connected to the ChlorGuard system control panel if
required. Other brands of sensor/transmitters can be used and connected to the analogue inputs to
the Control Panel.
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