POWER TRANSFORMERS IMPACT RECORDER - IMPORTANCE AND USAGE
What Is The Importance of Power Transformer Impact Recorders During Transport?
There are two types of impact recorders:
· Impact Indicator – is used in all power transformers that are equal or higher than 30MVA and/or of a voltage class equal or higher than 230kV for the domestic market. When the transformer is to be exported, such impact indicator is used in all power transformers that are equal or higher than 5MVA. Four (4) pieces are used, which are fixed to the tank sidewalls.
· Three-dimensional Impact Recorder – is used only when required by the customer and/or by an insurance Company. This reco rder is fixed to the main transformer lid, by means of fastening screws, the nearest possible to its geometrical center. The recorder is turned on before the transformer is loaded by Manufacturer and should remain turned on until the unit is unloaded.
They are intended to indicate whether chocks and vibrations have occurred in th e traver se, longitudinal and vertical directions during the transport, loading and unloading processes. The magnitude of vibration and chocks is recorded in terms of “g” (Multiples of gr avity acceleration), accord ing to TABLE 1.
TABLE 1 – ACCEPTABLE ACCELERATION VALUES DURING TRANSPORT
The ranges of the impact indicator are analyzed after the transformer is unloaded and should be sent back to Manufacturer transformadores. If they have proven to be out of the limits, the Technical Assistance Department will take all necessary steps.
However, if the recommended acceleration limits have been exceeded, it doesn’t mean that damages have occurred to the transformer. If such excess occurs, our technical department should carry out a deeper analysis of the occurrence, defining whether or not an internal assessment or eventually the adoption of another specific action is necessary.
It is necessary to take in account that not only the maximum value is imp ortant, but how many times such value has been reached during the transport.
The following procedures should be followed to turn off and remove the impact recorder:
· Remove the weatherproof protection;
· Check the box sealing for integrity. If damages are found, please report them immediately to Manufacturer
· Remove the box lid. In case of rain, do not allow the penetration of any kind of humidity to the inside of the recorder;
· Turn off the recorder;
· Mark the point where the transport process has been ended;
· Turn the recorder on;
· Close t he box lid;
· Unload the Transforme r;
· Remove the box lid;
· Turn off the recorder;
· Mark the point where the unloading process has been ended;
· Remove the impact recorder’s base from the unit;
· Replace the lid of the recorder box;
· Close the box with the supplied seal and send the impact recorder containing the roll of records to the sales department of Manufacturer, preferably using the same transporting company for return.
IMPORTANT: In case the transport and unloading work is carried out by the same Company, it is not necessary to turn off the recorder and switch its position between one and another operation.
Impact recorders are equipments that log shock value and the time it occurred. Impact reorders are used to monitor shipments where concealed damage is a key concern like Transformers. The purpose of using Impact Recorders for monitoring Transformers is:
ReplyDelete1. Determine any shock that may have caused a concealed damage.
2. Use the data to substantiate any insurance claims, as these recorders log the time of any impact that might have caused damage. The most modern loggers also allow location and data monitoring remotely.
3. To reduce warranty claims that may occur later during operation due to shock damage during Transportation. Usually this occurs due to concealed damage going unnoticed. Though this should be covered under transit insurance the cost is born by the Transformer manufacturer under warranty due to lack of proper use of impact
recorders.
4. The data collected over time can be used to empirically calculate Transformer fragility or improve Transformer designs
5. To form the first line of test to decide on whether more expensive tests like FRA should be done at site or not.
LogicLadder has published a handbook on transformer shipment monitoring and usage of impact recorders.