METHOD STATEMENT FOR THE INSTALLATION OF TRANSFORMER October 18, 2013 | webmaster
This method statement explains and covers the installation & inspection of cast resin Transformers. General Requirements
Transformer
shall
be
inspected
and
checked
against
the
relevant
general
arrangement drawing, approved material submittals etc.
Transformer shall be checked for any signs of damage occurred probably during the transport. The transformer shall be stored in sheltered, clean and dry ambient temperature. If any damage is found shall be notified to suppliers or relevant parties. DOWNLOAD EDITABLE METHOD STATEMENT NOW
The characteristics of the Transformer detailed on the rating plate shall be checked to those of the shipping documents and with those of the test report, which is attached to the transformer.
Each transformer shall be checked for the accessories, rating, name plate details, protection devices, indicators & terminal boxes.
Compliance of comments raised during factory inspection shall be checked if any.
The Presence of all identifying and warning levels shall be checked.
All material required at site shall be inspected, handled and store properly.
Any discrepancies, damage etc, shall be notified and reported for corrective action.
Material found not suitable as per approved material submittal shall be removed from site.
Proper storage shall be provided as per manufacturer recommendation.
An inspection request shall be raised for consultant approval upon receipt of the material at site.
DOWNLOAD EDITABLE METHOD STATEMENT NOW Installation of Transformers
he area to be verified for the civil work has been completed and Transformers installation works can commence.
Check area is clean for the positioning of lifting crane and transformers.
Extra
precaution
to
be
taken
before
lifting
transformer
&
manufacturers’
recommended special lifting eyes shall be used.
Transformer shall be lifted with maximum sling angle of 60 degree as per manufacturer’s recommendation.
If the transformer is complete with protection enclosure, roof shall be taken off to attach the slings.
Points of attachment shall be checked for cracked welds or loose nuts and bolts before lifting.
Guide ropes shall be used to prevent twisting or swinging of the transformer once it has been lifted clear of the ground.
Transformer shall not attempt to lift in high winds.
Transformer shall be placed down on the level surface capable of supporting its weight.
Transformer shall be placed on removable GI U channel at the place of its final installation.
For locating the transformer in the final location, suitable lever on the special points foreseen on the lower frames shall be used to act only and not on the magnetic core and/ or on the winding.
Transformer shall not be moved pushing the coils and the connections.
Cable support, cabling and terminations shall be completed as per approved drawings and manufacturer’s recommendation.
Installation of transformer shall be offered for inspection.
Transformer testing & commissioning method statement March 14, 2014 | webmaster
Below is a standard method statement which can be used as learning purpose and to prepare
further
professional
method
statement
for
testing
and
commissioning
of
transformers. Required tools for transformer testing & commissioning.
Portable Hand Tools / Tool Box.
Digital Multimeter
Earth Resistance Tester
Megger Tester.
Safety requirements tools such as safety shoes, safety helmet, safety glasses, fluorescent vest, and safety gloves to ensure maximum ability of safe work and dust mask when require.
Procedure Of Transformer Testing & Commissioning
Ensure only trained persons shall operate the power tools.
Ensure all concerned personals shall use PPE and all other items as required.
Ensure adequate lighting is provided in the working area at night time.
Ensure service area/work area openings are provided with barricade, tape, and safety nets.
Preparation for testing 1.
Prior to the commencement of any permanent works, areas and access will be inspected to confirm that they are in a condition for permanent works to commence ensuring the environment is clean and dry. Testing will commence only after the equipment is completely installed as per approved method statement for the installation of the Transformer and released for testing commissioning.
2.
All materials and relevant documentation to this testing works shall be checked by the responsible personnel prior to the commencement of testing activities.
3.
Before any Item of equipment is accepted for testing a visual inspection will be carried out on that equipment. Where defective equipment is found it will be reported to Consultant for further action.
4.
The testing Electrical Engineer/Supervisor should confirm the availability of necessary Three Phase AC power supply and Single phase for testing activities.
5.
The testing Electrical Engineer/Supervisor should confirm the availability of proper access to the site area in which the equipment have to be tested.
6.
When a satisfactory pre-testing inspection has been carried out, the testing work will commence.
7.
The testing Engineer will instruct the supervisor regarding the testing works and will arrange for all necessary schematic drawings, data sheets and test formats to be available at the testing area.
8.
The supervisor will check that all the necessary tools and equipment’s to be used for testing are available in the testing area.
9.
After the testing work is completed the supervisor checks all the testing equipment and returns to the storage cabin.
10.
While carrying out the testing work the Testing Engineer will fill all the necessary test formats. After completion of testing work the Testing Engineer will obtain the signature of relevant officials: Consultant.
Method of testing of Transformers: Visual inspection: - Correctness of installation, assembly. - Damage, paint, cracks checks. - Tightness Checks. - Earthing Connection Checks. - Labels/Markings Rating Plate Correctness Checks. - Ferrules/ terminal Numbering Checks. Insulation Resistance measurement for primary winding - Earth the Secondary winding
- Apply Voltage on the Primary winding - Observe readings and record in the test format Insulation Resistance measurement for Secondary windings
- Earth the Primary windings - Apply Voltage on the Secondary windings - Observe readings and record in the test format Windings Resistance measurement - Ensure the contacts at bushings are cleans - Hold the sensing probes across the conduct between which the contact resistance is to be measured (Test Current 10A DC). - Observe the reading and record in the test format. Ratio Measurement - Ensure that both the Primary and Secondary windings are not connected to any cables/Bus bar. - Ensure the tap Changer in lowest tap Position. - Apply three phase supply voltage (415 V AC) across the Primary Termination of the Transformer. - Measure the secondary (LV) voltage at the LV termination. Observe the reading and record in the test format. - If the tap changer is Off load type, switch of the power supply and rise one step and apply the Three phase 415 V AC across the Secondary termination and measure the voltage at both Secondary and Primary side.
- The above step to be carried-out until the highest tap. Alternatively, test is performed with a digital ratio meter which measures the ratio value of the transformer and simultaneously checks the vector group and the polarity. Vector group Checks - Ensure that both the Primary and Secondary windings are not connected to any cables /Bus bars. - Connect the “R” phase of the Primary winding and “R” phase of the Secondary winding (Short R phase of Primary and Secondary termination). - Apply 3 phase supply voltage (415 V AC) across the Primary Termination of the Transformer. Measure the voltage at the both Primary and Secondary termination at all the phases. Observe the reading and record in the test format. - Apply the formula or plot the values in the graph to get the vector group. Magnetic Balance Test - Ensure that both the Primary and Secondary windings are not connected to any cables/Bus bars. - Apply 3 phase supply voltage (415 V AC) across the 1U & 1V and measure the Corresponding Voltage for 1U-1V, 1V1W & 1U1W. - Switch off the Supply and repeat the test again by applying the voltage in 1V & 1W and Measure the corresponding voltage for 1U-1V, 1V1W & 1U1W. - Again, Switch off the Supply and repeat the test again by applying the voltage in 1U & 1W and Measure the corresponding voltage for 1U-1V, 1V1W & 1U1W. - Observe the reading and record in the test format. On site Protection Until the Equipment is permanently energized, client should ensure that a protective cover will Remain over all the equipment that is being tested.
Installation Of MV LV Switchgear & Panels – Method Statement February 6, 2013 | webmaster
This method statement for installation of medium and low voltage switchgear and panels boards on site is prepared to define the method used to ensure that all MV/LV switch gear and panels site assembly, installation, final connection and workmanship is correct and acceptable and conforms to the contract documents & electrical specifications. Site construction Manage, electrical engineer and Quality engineer are responsible for site implementation of below method statement.
Pre Installation Checks
Prior to the commencement of any works, access and installation areas will be inspected to confirm they are in a suitable condition to commence installation.
Housekeeping pads or pertinent structure are complete and leveled within (±5) by civil contractor, for all plinth sizes.
Site supervisor to carry out pre-Installation
Inspection of switch-gear panels plinth prior to off loading and positioning in accordance with.
Construction department will ensure temporary protection is provided to protect the openings during installation and until the final connections are made to the Motor Control Centre.
Check equipment schedule for correct location and reference for the switchgear and panels.
If the switchgear or panels cannot be installed immediately, then the same shall be stored in clean, dry and properly ventilated location.
Switchgear & Panels Installation Procedure
Fully crated switchgear or panels shipped on a timber sub-base will only be lifted under the sub-base, in between the bearers, using soft sling’s (Nylon webbing) with spreader bars on the topside of the crate.
When transferring to a fork lift, or unloading with a fork lift, the mast must be as close as possible to the face of the crate. Forks must be fully projected under the crate.
Lift switchgear or panels squarely, then tilt back towards the fork lift before moving.
When the switchgear or panels has been moved its final destination, it will be uncrated, unpacked and removed from its timber base.
Lower switchgear or panels onto lengths of steel conduit or skate (rolling devices), for movement to final location.
Care will be taken to ensure the switchgear or panels does not overbalance whilst being moved to its final location.
Once in its final location on the “Housekeeping Pad”, rolling device’s will be removed from under the switchgear or panels. Again caution will be exercised against over balancing, while the panels are being moved.
Finally the panels should be free standing, self supporting assembly, and will be bolted to the “Housekeeping Pad” with anchor bolts ensuring the assembly is horizontal and vertically in alignment as detailed on the construction shop drawings.
Assembling the Switchgear & Panels At Site
When the switchgear or panels are shipped in more than one module, it will be necessary
to
bolt
in
individual
section
together,
in
the
presence
of
manufacturer/supplier representative.
Construction drawings will indicate the relative positions of each section being supplied and shipped.
All fishplates to interconnect bus bars will be carefully installed after removing the appropriate cover plates.
All connections will be torqued to the required figure as per data from the manufacturer.
Busbar Assembly Torque Data: Torque setting for fault level Bus-Bars using ISO M8.8 graded cadmium plated bolts or set screws.
M6 Bolt or set screw
7 lbs ft. 8.6 Nm
M8 Bolt or set screw
15 lbs ft. 20.4 Nm
M10 Bolt or set screw
23 lbs ft. 33.6 Nm
M12 Bolt or set screw
40 lbs ft. 54.0 Nm
M8 set screw into Brass Pittar
15 lbs ft. 20.4 Nm
Termination Of Incoming Cables
The switchgear or panels shall be provided with terminals for both power and control cables. The terminal will be positioned in such manner as to facilitate optimum access to suit the specified type of entry. As detailed on the construction/shop drawing.
Operate all components (i.e.. fuse switches, circuit breakers, contactors, relays etc) by hand to ensure that there are no damage to the moving parts.
A thorough inspection will be carried out to determine that no foreign matter (tools etc) have been left in the panels after field installation is completed.
Particular attention will be given to the Busbar compartment, ensuring it is free of debris and moisture. All compartments shall be thoroughly cleaned.
All busbar and circuit connections shall be checked carefully to find these are tightened and torqued from the factory, as it is possible for connections to vibrate loose during shipments.
All connections are checked for tightness/torque prior to energization in accordance with the manufacturer’s recommendation.
All components/door interlocks should be adjusted correctly and must operate freely.
After the above operations, all doors are closed and locked and keys should be maintained by the supervisor until panel is ready to handover to the commissioning team.
Testing Of Switchgears & Panels All site testing for will be carried out as per specifications and manufacturer instructions. The supervisor in charge and the QC officer will continuously monitor the activities to ensure that all components on the approved construction drawings and coordinated service drawings have been installed and that the panels installation is completed in accordance with the contract requirements and manufacturer’s recommendations. All the necessary records shall be maintained as per approved standard formats.
