Electrical and instrumentation loop check. Reference number IEC E. For example, edition numbers 1. Information relating to this publication, including its validity, is available in the IEC Catalogue of publications see below in addition to new editions, amendments and corrigenda. Information on the subjects under consideration and work in progress undertaken by the technical committee which has prepared this publication, as well as the list of publications issued, is also available from the following:.
|Published (Last):||8 June 2005|
|PDF File Size:||12.80 Mb|
|ePub File Size:||12.30 Mb|
|Price:||Free* [*Free Regsitration Required]|
Electrical and instrumentation loop check. Reference number IEC E. For example, edition numbers 1. Information relating to this publication, including its validity, is available in the IEC Catalogue of publications see below in addition to new editions, amendments and corrigenda.
Information on the subjects under consideration and work in progress undertaken by the technical committee which has prepared this publication, as well as the list of publications issued, is also available from the following:. On-line information is also available on recently issued publications, withdrawn and replaced publications, as well as corrigenda.
Please contact the Customer Service Centre see below for further information. Email: custserv iec. Annexe A informative Test report for analogue input loop The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work.
International, governmental and non- governmental organizations liaising with the IEC also participate in this preparation. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user.
Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. Use of the referenced publications is indispensable for the correct application of this publication. IEC shall not be held responsible for identifying any or all such patent rights. This first edition constitutes a technical revision. The text of this standard is based on the following documents:.
Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. At this date, the publication will be. A bilingual version of this publication may be issued at a later date. The inspection and verification of the individual measurements and controls in conjunction with the control systems used to monitor these devices DCS, PLC, etc.
In industry, numerous methods and philosophies are used to check the instrumentation and controls after mechanical installation within projects for modified or new facilities. This standard was created to provide a better understanding of what loop check consists of and also to provide a standard methodology for executing loop check. The annexes of this standard contain forms which may be used in the check procedures. Buyers of this publication may copy these forms for their own purposes only in the required amount.
This International Standard describes the steps recommended to complete a loop check, which comprises the activities between the completion of the loop construction including installation and point-to-point checks and the start-up of cold commissioning.
It does not include a detailed checkout of power distribution systems, except as they relate to the loops being checked i. For the purposes of this document, the following terms and definitions apply. NOTE Please refer to the enclosed annexes as an example.
This is a milestone marking the end of the precommissioning activities. NOTE At this stage, the operating range of every instrument loop is already adjusted to reflect the actual working condition. NOTE At this stage, the plant is ready for full and continuous operation. In the case of safety loops, any safety switch point should be included if it is not in the basic database. The loop checks will ideally occur in the precommissioning phase of the schedule shown in Figure 1.
However, normal occurrence is that the loop checks begin when any specific loop is completed and turned over to the checkout crew even if it is during the "construction" phase. The loop check could substantially overlap the "construction" phase.
Acceptance of plant. Figure 1 — Definition of phases and milestones. The main activities in the cold and hot commissioning phases are system verification tuning of loops and instruments and control schemes. They all are visualized on DCS. In the case of safety loops, all safety switch points should be included if they are not in the basic database. The actual loop check involves three phases. It checks that all the components function correctly and that the DCS or panel readouts are accurate.
Figure 2 — Loop check. There are three types of deficiencies that can be found during the loop check. The construction contractor should fix these problems. Additional deficiencies might be in the process design, but this can only be determined after process start-up.
Are the field elements adequately protected from mechanical or environmental damage? The function checks are ideally performed in well-defined blocks. The actual method and order of checkout should be defined by the project team prior to starting the loop check. The purpose of the function check is to exercise all the components of a loop during one test and measure their accuracy.
Checking out a loop in pieces does not qualify as a function check and shall not substitute for the function check. The actual check involves connecting a testing device to the transmitter and increasing the signal, in increments, to full span to insure that the DCS or panel readout follows the input.
Also, if the loop has an output, the actuator should be observed to verify that it follows the incremental output changes within a specified tolerance. In the final element actuator a failure should be enforced or simulated to verify the correct failure reaction. Motor loops should be checked for correct operation and overload protection before coupling the motor to the driven device. Note that the grounding checks meggering should be done as part of the construction phase, though this may be repeated in the checkout phase.
Check of inter-loop functionality like analogue control loops or interlock functions is preferably carried out for integrated units after a successful checkout of the separate sensor and actuator loop. This is most effectively completed during cold commissioning.
Safety, quality and environmental loops. If the actual measurement cannot be simulated as in a flowmeter , the test should be completed during cold commissioning. If this is impractical, the meter should be specified to be separately tested by the manufacturer and the test report included with meter. Also, if a tank has a secondary level switch that is deemed to be a safety device, the tank level should be increased to trip the switch as installed.
If this is not practical, a test method should be devised to ensure that the device functions correctly as installed. In particular, that it actuates at the correct level to prevent overflow. Does it switch back correctly?
The loop-related concept checkout results are to be recorded on the loop test report. Loop- related concept checkout is performed for each loop typical and for all safety and quality loops. For non-safety loops, these tests are performed only frequently enough that each concept is checked. The prepared documentation set according to the process unit contains.
The following annexes or PC tools Excel files contain examples of test reports per loop type. The results of the loop checks shall be indicated as follows. The test reports are drafted in such a way that all relevant items are covered at least once. Quality is guaranteed by the following measures. For safety installations, extra checklists and working plans are set up in addition to the normal loop-check procedure.
These documents typically describe a very detailed check procedure and are periodically repeated after production start-up. Annex A informative. Function Purpose Phase Temp. Changes in installation or software functionality require recheck. Instrument type: Results 1. Documentation check Italics denote: normally not present Loop documentation complete? Visual inspection Are the elements of the loop complete, coded, installed in a clean and neat manner? P PR F Cable glands and connections tight?
Name Do the instruments conform to the circuit diagrams loop diagram and specification sheets? Signature Individual configuration of cards, transmitters, etc.
Function check Function of PCS loop successful? Signature Accept. Span and units on read out OK? No check due to operational reasons? Loop brought back ready for commissioning? Status: Date Issued to checkout crew Issued to repair crew Description of repair use other side Issued to constr. Annex B informative. Test report for binary input loop. Test report for binary input loop January Complex Process area Subprocess Techn.
Instrument type: Liquiphant Results 1. F Fail. Description Remarks: of failure use other side.
IEC-62382 Electrical and Instrumentation Loop Check
This standard defines procedures and specifications for loop checks, which comprise the activities between the completion of the loop construction including installation and point-to-point checks and the start-up of cold commissioning. While the content is largely the same as IEC , this adoption includes such changes as:. About ISA Founded in , the International Society of Automation is a leading, global, nonprofit organization that is setting the standard for automation by helping over 30, worldwide members and other professionals solve difficult technical problems, while enhancing their leadership and personal career capabilities. Based in Research Triangle Park, North Carolina, ISA develops standards, certifies industry professionals, provides education and training, publishes books and technical articles, and hosts conferences and exhibitions for automation professionals. ISA is the founding sponsor of the Automation Federation. Did you enjoy this great article?
Electrical and instrumentation loop check
ISA Loop Check Standard Approved by ANSI