Performing Routine Maintenance

　　Performing Routine Maintenance

　　Routine maintenance consists of the following tasks:

　　• Checking the integrity of system power sources

　　• Periodically enabling “disabled” Output Voter Diagnostics (OVD)

　　• Verifying the integrity of spare modules

　　You should establish a schedule for routine maintenance and adhere to it to ensure maximum safety and long service.

　　Checking System Power Sources

　　Typical installations use redundant power supplies to power the controller and the field circuitry. Under normal operating conditions, the required power is shared between the two power sources. Typically, the sharing is approximately equal with each power supply providing 50 percent of the system power.

　　Under abnormal conditions, one of the power sources may be required to provide 100 percent of the system power. To verify the integrity of the system power supply, you should periodically test each power source for its ability to provide power for the entire system when the redundant source is disabled.

　　To verify the stability of the remaining power source under full load, every three to six months, turn off one of the power sources and leave it off for several minutes. After restoring power, repeat the test for the other power supply.

　　Ideally, this type of testing is performed with the controlled process offline; for example, during a normally scheduled plant maintenance period. Remember to turn on both power sources prior to restarting the controlled process.

　　Output Voter Diagnostics (OVD)

　　Output voter diagnostics (OVD) is a set of tests that detects failures in the output voting circuitry of DO Modules only. OVD runs without operator intervention or awareness and enables the Trident controller to continually verify its own integrity.

　　If OVD is disabled, you should verify that the output voter circuitry is working properly by enabling OVD every three to six months. All DO Modules can be tested simultaneously.

　　To enable and disable OVD, use the appropriate system attribute in your TriStation project. Leave OVD enabled for several minutes. When testing is done, disable OVD.

　　Verifying Spare Modules

　　The controller automatically tests all modules installed in the system. The only action needed to guarantee the integrity of a spare module is to periodically install it in an online system.

　　Spare I⁄O modules should be installed as hot spares. The controller automatically tests these modules by shifting control between the active and hot-spare modules as follows:

　　• Periodically, approximately once an hour

　　• After a power failure

　　• After an MP re-education

　　Spare MPs and I⁄O modules that cannot be used as hot spares should be periodically rotated into an online system to ensure the integrity of spare inventory. A rotation schedule should be established so that a spare is not allowed to sit on the shelf more that six months.

　　Overview

　　Indicators are lights on the front panel of each module that identify the state of each module. Each module includes indicators that identify the general state of the module and other indicators related to the function of the module.

　　The types of indicators include:

　　Status indicators which identify the processing state of the module. Each module includes a Pass, Fault, and Active indicator.

　　A lock indicator which identifies whether the module is unlocked.

　　Mode indicators which identify the current operating state of the controller. (Only on MP Modules.)

　　Field power and power load indicators which identify whether a power problem has occurred. (Only on some I⁄O modules.)

　　Communication indicators which identify the type of communication occurring. (Only on MP and CM Modules.)

　　Points indicators which identify whether the point is energized.

　　Alarm indicators which identify alarm conditions for the controller. (Only on MP Modules.)

　　Fault and Alarm Indicators

　　Fault indicators identify potentially serious problems with a module. Alarm conditions identify abnormal field conditions such as loss of power and loss of communication.

　　If a fault or alarm indicator is on, you should consult the appropriate section of this chapter and take appropriate action. This action may include replacing a faulty module or repairing a faulty circuit or device.

　　Identifying Fault and Alarm Conditions

　　You can identify alarm and fault conditions in the following ways:

　　By examining the indicators on the front panel of each module and consulting this chapter.

　　By using the Diagnostic Panel in the TriStation application. For more information, see the TriStation 1131 Developer’s Guide.

　　Main Processor Indicators

　　This section describes indicators for the MP Module, including the MP status, system mode, alarm, and communications indicators.

　　MP Status Indicators

　　The MP status indicators identify the processing state for the MP Module. A fault light indicates that the processor has an internal fault.

Related product recommendations:
TRICONEX   3504E
TRICONEX   3511
TRICONEX   3515
TRICONEX 3601E
TRICONEX 3604E
TRICONEX 3607E
TRICONEX   3623T
TRICONEX   3625
TRICONEX  3625A
TRICONEX   3625C1
TRICONEX   3625
TRICONEX 3636R
TRICONEX   3664
TRICONEX 3700A
TRICONEX 3703E
TRICONEX   3708E
TRICONEX   3708EN
TRICONEX   3721C
TRICONEX 3721
TRICONEX   3805E
TRICONEX   3806E
TRICONEX 3902AX
TRICONEX 4000056-002
TRICONEX 4000066-025
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