QC PROCEDURE FOR INSTALLATION OF LOW VOLTAGE DRY TYPE TRANSFORMER

Table of Contents

SCOPE

PURPOSE

DEFINITIONS

REFERENCES

RESPONSIBILITIES

SAFETY

PROCEDURE

ATTACHMENT

SCOPE:

This Quality Control Procedure covers inspection, test of material, installation and Pre-Commissioning activities for the new installed building and Substations in Package 1 Haradh Hawiyah Field Gas Compression Project.

PURPOSE:

The purpose of this procedure is to define the activities, responsibilities and documentation for controlling in the installation and inspection of Low Voltage Dry Type Power Transformer.

DEFINITIONS:

COMPANY SAUDI ARAMCO

CONTRACTOR

SUB CONTRACTOR

PROJECT

SAPMT SAUDI ARAMCO PROJECT MANAGEMENT TEAM

SAPID SAUDI ARAMCO PROJECT INSPECTION DIVISION

SAPOD SAUDI ARAMCO POWER OPERATION DISTRIBUTION.

REFERENCES:

Approved IFC Drawings

SAES-P-121 Transformer and Reactor

SAES-P-111 Grounding

SAES-P-104 Wiring Methods and Materials

SAES-P-100 Basic Power System Design Criteria

SAES-P-119 Substation

SABP-A-114 Excavation and Backfill

SAES-J-102 Electrical System for Instrumentation

PQAM/QCIP Project Quality Assurance Manual / Quality Control Inspection Plan

IEEE Institute of Electrical and Electronics Engineers

IEEE 81 NEC National Electrical Commission

NFPA 70 National Electrical Code (NEC)

NFPA National Fire Protection Association

NEMA National Electrical Manufacturing Association

UL 467 UL Standard for Grounding and Bonding Equipment

Saudi Aramco Library Drawing

RESPONSIBILITIES:

5.1 Project Manager:

An authorized sub-contractor representative towards Contractor, Sub-Contractor and other relevant agencies and authorities to manage this project, it is overall responsibility of the PM to organize resources to perform construction activities as per project specification, in compliance with quality, schedule, safety and standard requirements.

5.2 QA/QC Manager:

Shall be responsible to manage overall QA/QC activities and interacting with related to all QA/QC activities of the project. He shall be responsible for Nonconformance Management and Quality Audit.

5.3 QC Supervisor (Electrical):

Approved Electrical QC Supervisor shall perform an immediate subordinate to QC manager to overall assist his activities. Supervision of sub-contractor QC electrical Inspectors activities in inspection, organize the field inspection as per schedule and QC mobilization plan. Completely read out the relevant application and project specification. Provide guide and training for the QC inspector personnel. Prepare inspection reports, matrix log, and Two Week Look Ahead schedule.

5.4 Safety Manager:

Shall be responsible for all the safety requirements are fulfilled prior to start of the job and during the works, Job safety analysis/safety task assignments will be strictly implemented and make sure that all the activities are fulfilled as per project safety requirements.

5.5 Construction Manager:

Shall be responsible for construction activities are executed according to the relevant project specifications, in compliance as per required quality of work. Take all preventive and precautionary measures during execution of work. He should also ensure that all necessary safety protective equipment is provided to each and every individual involved in the work.

5.6 Electrical Supervisor:

Responsible for construction work supervision. Ensure that all the work being executed is meeting conformity with IFC drawings, project specifications Engineering standards, and HSE requirements. He is the responsible for allotment and supervision of every individual group. Conduct Tool Box Talk, Guide, Monitor the work force and report to the construction manager in regular basis. Also ensure that necessary permits have been taken for all the work involved and maintains the records on regular basis.

5.7 Electrical QC Inspector:

Approved Electrical inspectors shall be responsible for carrying out of all stage wise inspections and preparation of inspection documents. Ensuring the RFI for Client inspection are raised as per Site Progress. Ensure and coordinate with Client for the release of clearance acceptance in post inspection activities closure and acceptance signature for availability of the work area to next activities. Ensure all drawings, construction materials and tools shall be approved during inspection activities.

5.8 HSE Officer:

Overall responsible for the safety related aspects of work at site. Ensure that all activities are undertaken and installed in a safe manner as per the HSE Plan.

SAFETY:

All work shall be implemented as per project site work permit system and shall ensure that work permit is updated and valid. All person involved in these activities shall wear complete appropriate Personal Protective Equipment (PPE) in accordance with safe work requirements.

Ensure equipment’s used for operation are approved with update color code marking and in compliance with safety requirements

Conduct everyday job safety talk before starting the work. As well that the work area shall be kept clean and in tidy manner in all time.

Check adequacy and availability of all electrically driven power tools and equipment shall be properly grounded. When working in height use only approved green tagged scaffold working platforms and attain 100% tie-off safety policy.

Barricades and Signboards shall be installed around the working area to restrict others not involved in these activities.

PROCEDURE:

General Requirements:

Confirm Dry Type LV Transformer size / type and assembly shall be inspected on receipt complete and meet the specified requirements in accordance with project approved IFC drawings.

The QC Inspector shall prepare and maintain records of all inspections and tests of Dry Type LV Transformer required by this procedure.

Inspection and verification site tests of Dry Type LV Transformer shall be witnesses, recorded in approved RFI documents signed by the Electrical QC Inspectors (sub-contractor and SA).

Dry Type LV Transformer Testing equipment’s shall have up-dated valid calibration certificate.

Materials and Equipment Handling:

Dry Type LV Transformer received at site shall be inspected, handled and stored upon receipt in accordance with Aramco standard SAEP-P-385 Preservation of Materials and Equipment, Appendix A – Electrical - Table A-3003

All handling, storage of Dry Type LV Transformer shall be performed in a safe manner as to avoid mechanical damage.

When transporting or unloading Dry Type LV Transformer, extra care must be observed. A set of rubber, paper-box or wooden support shall be used under the Dry Type LV Transformer to avoid surface scratching in contact on the floor. Gloves should be worn to avoid smudges and fingerprints as also for the protection of workers.

Installation and Test Procedure:

Supports and Foundations:

Verify the Dry Type LV Transformer concrete pedestals, anchor bolts, hangers, channels, saddles, etc., prior to installation of equipment and apparatus as shown on the approved IFC drawings and specified in the various sections as per the project specification requirement.

Upon Dry Type LV Transformer installation, the support will be checked to ensure high rigidity, and its locations with complete accessories and fittings.

Check the relevant document for concrete foundation for level and correctness.

Check the relevant document for epoxy painting over foundation before installing transformer.

Installation Check (Visual Inspection):

Dry Type LV Transformer shall be installed in accordance with the manufacturer's recommendations, good electrical engineering practice, project specifications and the approved IFC drawings.

Compare Dry Type LV Transformer received nameplate data with approved IFC drawings detail.

Check the Dry Type LV Transformer and accessories for any physical and mechanical damage before and at the time of installation.

Verify the Dry Type LV Transformer incoming and outgoing power terminal side point if it is matching with the approved IFC drawings.

Check the grounding point in equipment and grounding stub up location.

All metal surfaces to be bolted shall be checked for cleanliness before assembly. Inspect electrical bolted connections for high resistance using calibrated torque wrench and low resistance ohmmeter. Torque value shall be as per manufacturer’s recommendation or as per Electrical System Standard and shall be recorded.

All the inspection and test activities for the dry type LV transformer shall be performed as per Quality Control Procedure and shall be with accordance to vendor instructions and Installation manufacturer manual.

Testing Procedure:

The following shall be the guidelines for the testing personnel during the Inspection and testing of Dry Type LV Transformer.

Test (Visual and Mechanical check).

Perform specific inspections and mechanical tests as recommended by manufacturer.

Verify that core, frame and enclosure groundings are correct.

Verify the connection and operation of the load tap changer.

Ensure the Torque test for terminal connection and recorded as per Vendor instruction.

Low Resistance Measurement For Bolted Connections:

Test Equipment: Micro-Ohmmeter (DLRO or T&R).

Use safety grounding devices to discharge any trapped charges before connecting/ disconnecting any test lead or other connection to/ from the transformer.

First torque-check the exposed connection/joints. The torqueing values should be as per manufacturer recommendation. Check that the contact surfaces for the current and voltages probes are clean and dry.

Check that the instrument probes are clean and dry.

Check that the micro-ohmmeter is switch-off during making connections.

Micro-ohmmeter must be connected to ground.

Connect the current and voltage cables, with respect to the polarities, as in figure 1. Always connect the voltage cables inside the current cables.

Fig.1

Switch on the micro-ohmmeter. Increase the current to the desired value. Read the resistance value.

Compared measured values with manufacturer’s specifications, compare results between different connections. Differences greater than 50% between connections should be investigated.

Insulation Resistance Test and Polarization Index Test

Transformer windings shall be mega ohmmeter tested with the transformer tank and core grounded complying the specification SATIP-P-111-01 and shall be recorded.

A 1000 V mega ohmmeter shall be used for winding less than 1000 volts, a 2500 V for higher voltage winding rated up to 4000 volts, and a 5000 V mega ohmmeter rated 4000 volts and above.

The minimum acceptable insulation resistance shall be in accordance with manufacturer’s instructions or the limits given by the equation R=K (1+kV), whichever is greater. R is the minimum acceptable insulation resistance (in mega ohms), kV is the voltage ratio of the winding (in kV), and K is a factor depending on winding temperature as mentioned in client requirements. And it is recorded

Test Equipment: Mega-ohmmeter, Thermometer and Humidity meter.

Measure and record the ambient temperature and humidity.

Check if the enclosure and core are grounded.

Use safety grounding devices to discharge any trapped charges before connecting/disconnecting any test leads or other connections to/from transformer.

Disconnect all high voltage, low voltage and neutral connections of the transformer.

Disconnect all low voltage control systems connected to the transformer.

Set the test voltage according to the manufacturer’s specification.

For two-winding transformers take the following measurements: a) HV winding to LV winding and ground and b) LV winding to HV winding and ground.

Take measurements of insulation resistance at 1 minute and 10 minutes. Compare measured insulation resistance with manufacturer’s test values. The measured values should be corrected to 20 ºC by multiplying them with correction factors.

In absence of reliable data the following formula may be used for transformers:

IR = CE /kVA1/2.

Where: IR= minimum 1 min DC insulation resistance in mega ohms.

C= 1.5 at 20⁰C; C=0.8 for tests of winding with other windings grounded.

E= voltage rating of the winding under test.

KVA= rated capacity of winding under test.

Calculate the polarization index, as R10/R1, where R10 is the insulation resistance measured after 10 minutes and R1 is the insulation resistance measured after 1 minute.

A polarization index greater than 2.0 indicates a good insulation.

The Polarization index (PI) test of transformers shall be checked using an insulation resistance tester complying the specification SATIP-P-121-01 Paragraph 4.1 (Pre-Commissioning). And it is recorded.

If the core ground is accessible disconnect the connection to ground and measure the insulation resistance of the core connection to ground. The test voltage should be set as per the manufacturer’s recommendations or 250V if the value from the manufacturer is not available, and the test duration 10 minutes. A polarization index should be calculated and the insulation resistance should be temperature corrected.

ATTACHMENTS:

Insulation Resistance Record Transformer

Inspection and Testing Checklist Transformer

Polarization Index Test

Torque Value Record (Electrical Equipment)

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QC PROCEDURE FOR INSTALLATION OF LOW VOLTAGE DRY TYPE TRANSFORMER | ARAMCO PROJECT