IS215UCVEM09A VMIVME-017614-132 VMIVME-7698 – GE

Description

Analog I/O modules typically contain 10 analog inputs and 2 analog outputs. 8 inputs can be configured for 1-5Vdc, ±5Vdc, ±10Vdc, or 0-20ma with jumpers on the module, and the remaining 2 inputs can be configured for 0-20ma or +/-1ma with 250 Ω / 5,000 Ω burden resistors respectively. For applications with a high concentration of analog outputs, dedicated output modules are available for 0-20ma and others for 0-20ma / 0-200ma selection for valve actuators (800 Ω / 50 Ω output loads respectively). Transducers can be externally powered (differential inputs) or internally powered from the I/O module with +24Vdc current limited per point. I/O modules are available with point isolation for externally powered transducers.

In general, RTDs are useful for precision temperature measurements below 800°C, and thermocouples are cost effective devices for monitoring a wider temperature range. RTD modules provide a 10 ma multiplexed excitation current to each RTD, which can be grounded or ungrounded. They support 100 and 200 Ω platinum, 10 Ω copper, and 120 Ω nickel 3-wire RTDs with software linearization per point. The linearization includes scaling for specific RTD standards such as a MINCO-CA or CU10 10 Ω copper RTDs. RTDs can be located up to 300 meters (984 feet) from the I/O module with a maximum two-way cable resistance of 15 Ω.

External equipment is the most basic component of the control system, and once a fault occurs, it will directly affect the control effect. The local electric valve, electric actuator, and solenoid valve are faulty, and the corresponding valves refuse to operate, making control impossible; A component transmitter, two position switch, thermocouple, and thermal resistor malfunction results in incorrect signal collection, and the status and control effect of on-site equipment cannot be fed back to the control center. The DPU is unable to control it and may issue incorrect commands. So once external equipment malfunctions, it should be promptly addressed. There are two types of faults in electric doors, electric actuators, and solenoid valves: electrical faults and mechanical faults.

Electrical faults mainly refer to power supply faults. The power circuit of the electric door is divided into two parts: the power supply and the control power supply of the electric door. In general, the control power supply comes from one phase of the power supply. When one or more phases of the power supply lose power, the electric door will not be able to operate. When the control power supply loses power, the control circuit of the electric door cannot receive control commands, and the electric door cannot move. When operating the electric door from the OM screen, a timeout fault will occur, indicating that the electric door has not acted according to the operating instructions. At this point, the voltage of each circuit should be checked in a timely manner. If it is normal, corresponding measures should be taken. If the voltage of each circuit is normal, the circuit and external equipment should be checked.

The control and power supply mode of the electric actuator is basically the same as the power supply mode of the electric door. In automatic mode, the electric actuator is controlled by a servo amplifier, and the power supply of the servo amplifier is provided by UPS. When the servo amplifier loses power or malfunctions, the automatic adjustment circuit fails and can only be manually operated through a manual operator. Electromagnetic valves are generally divided into two types: AC and DC. The power supply of electromagnetic valves is generally directly supplied by external power sources, and the control circuit controls the power circuit of the electromagnetic valve through a relay. When the power supply of the solenoid valve fails, the solenoid valve cannot operate. Mechanical faults generally include mechanical jamming, incorrect limit adjustment, etc. Handle according to mechanical principles.

Transmitters, two position switches, thermocouples, thermal resistance transmitters, two position switches, thermocouples, and thermal resistance belong to primary components. If a primary component fails, the sampling voltage and current should be checked first to see if they are normal, and then the working condition of the local component should be checked. Replace the corresponding sampling board with a faulty one; Local component failure may be due to a component failure or a circuit issue, which should be handled separately based on the actual situation. The widespread application of decentralized control systems in power plants has greatly improved the automation level of steam turbine generator control systems, reduced the labor intensity of operation and maintenance personnel, and implemented many advanced control functions and strategies. However, as a control system, due to its extremely large and complex composition, hardware or software failures inevitably occur, leading to instability of the control system and affecting the safe operation of the unit.