A question regarding the quotas for instrument calibration and installation
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Volume 10 of the Unified Installation Quotas, which deals with the installation of automation control instruments, contains information on instrument calibration. One section in Chapter 2 on process control instruments deals with simulation experiments for instrument circuits, while another section in Chapter 5 on the calibration of basic automation devices focuses on the calibration of I/O components. So, the commissioning work typically carried out by the construction party refers to simulation tests of the instrument circuits. However, this quota does not cover tasks such as interlock commissioning; should the provisions in Chapter 5 regarding the commissioning of process I/O components be applied in such cases? On the other hand, it seems that the content of Chapter 5 relates to FAT activities, so perhaps it is not applicable to simulation tests of on-site instrument circuits or interlock commissioning. In instrument circuit simulation experiments, the quantity of work involved should be calculated by counting the types and numbers of circuits based on the circuit diagram. However, in typical on-site simulation tests, a 4-20mA analog signal is applied at the instrument terminals to check whether the signals displayed in the control room are correct, or the valves are operated from the control room to verify whether they move as intended (what is commonly referred to as confirming operation). The proper approach should be to apply an analog signal at the instrument terminals and then check whether the valves corresponding to those terminals in the circuit diagram actually move. Of course, for simple display instruments, it is sufficient to apply an analog signal alone.
The question raised by the poster is quite technical, involving the application of specific standards. Drawing on my own experience in project management, I would like to share some insights for reference: 1. The work related to instrument installation and debugging can be divided into two main categories: one is individual device debugging (commonly known as primary debugging), and the other is system debugging. 2. As the original poster mentioned, component-level debugging refers to the checks carried out during SAT; applying I/O component debugging will suffice. 3. Circuit testing refers to a system test of all components, from the components on-site to the display in the control system, or a system test of all components from the control system to the components that carry out operations on-site; therefore, this aspect can be covered by circuit testing. 4. We deducted a portion of the workload in actual implementation, as it was the employees of our own company who were responsible for configuring and maintaining the control system, while the construction party was only tasked with on-site work and cable installation.
It is clearly stated in the specifications for individual unit testing: SAT is generally carried out by the manufacturer of the cabinet or by the owner. As the construction party, one can only conduct circuit simulation tests from the on-site instruments to the DCS. However, such circuit simulation tests cover too little – there is no guidance on how to calculate interlocks or SIS functions. These are all tasks that actually involve people, machinery, and resources. Configuration and maintenance, I think, are just system-related tasks; those should already be included in the contract for purchasing the cabinets. So what I mainly don’t understand is how interlocking is calculated. My construction unit has also carried out this work, and it should be reflected in the handover documents. But how can the costs related to labor, materials, and equipment for this work be included in the final quota?
The construction party only carries out individual testing, ensuring that the connections at the site and within the cabinet rooms are correct, as well as that the internal components of the system are properly tested; once that is done, the task is considered complete. The remaining large-scale interlock tests are to be carried out by the owner – is that how it should be understood?
The other quotas aren’t very clear; we have always used Shandong Quotas 06 and 16. For the construction party, the primary calibration of the instruments is included in the installation process; the secondary calibration refers to what is commonly known as point setting. We carry out circuit simulation tests, and for interlock calibration, we base it on the motors. In the case of relay interlock system failures, this sub-item is divided into two levels: 6 points and 16 points. Motors typically have states such as start, stop, fault, operation, frequency control, and frequency return – usually within 6 points.
So, does your chain borrow the prices of electrical quotas?
Individual unit testing is included in the cost for instrument installation as per the specifications; therefore, the construction party must carry out both individual unit testing and instrument installation in order to be covered by the specified costs for instrument installation – otherwise a penalty will be imposed. Combined testing involves simulation tests of the instrument circuits as well as tests for electrical instrument interlocks.
Instrumentation-based, not electrical; a centralized monitoring and control device – a sequence control device. 06 refers to the relay interlocking protection system, while 16 denotes an accident in the relay interlocking system
This post was last edited by fjw3081585 on 2019-7-12 at 11:02. How many points are in your set, based on the number of interlock points per motor? But literally speaking, these are all accident points; are analog values such as current signals and voltage signals also calculated in this way?
Hello, I’m also from Shandong. I’m currently facing quite a few challenges with instrument calibration. Could I add you on WeChat to discuss this?