What is the transformer lifecycle?

A series isolation transformer is selected, installed and commissioned, run, maintained and eventually replaced, and records tie each stage to the next so its condition is known throughout.

TRANSFORMER PIT LIGHT FITTING ISOLATION TRANSFORMER SERIES CIRCUIT CONSTANT CURRENT FROM THE CCR MAINTENANCE RECORD RIGHT TYPE · RIGHT RATING SEAT · CONNECT · BASELINE TESTS CARRIES THE LOOP CURRENT INSPECT · TEST · KEEP DRY FAILS SPEC · REPLACE RECORD · DISPOSE STAGE CHOOSE WELL ILLUSTRATIVE · SERVICE LIFE VARIES WITH CONDITIONS

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primary winding
secondary / task focus
series circuit
pit
The Fact Asset practice

The transformer lifecycle is the working life of a series isolation transformer from choice to disposal. It is selected for the circuit’s current ratio, power rating and environment, installed and commissioned with baseline readings, run in the series loop, maintained by inspection and testing, replaced when it no longer meets the specification, and finally disposed of with the record closed.

There is no fixed service life: it depends on the quality of the unit, the environment, the loading and the maintenance. Moisture, heat, electrical stress and poor connectors shorten it, while a dry pit and sound connectors extend it. What ties the stages together is the record: readings taken at commissioning are the baseline against which every later test is compared, so condition, not age alone, shows when replacement is due. As with all work on the loop, isolate the circuit under site procedures first.

Select and Install
Right current ratio, power rating and environment, then a sound installation with baseline tests. See Transformer Pit and Transformer Connection.
Operate
It carries the loop current and passes it to the fitting. See Transformer Current and Transformer Voltage.
Maintain and Test
Inspection, dry pit, sound connectors and trended tests keep it healthy. See Transformer Maintenance and Transformer Testing.
Replace and Retire
Replaced when it fails or no longer meets the specification, then disposed of and recorded. See Transformer Failure Modes and Transformer Replacement.
StagesSelect, install, operate, maintain, replace, retire
BaselineReadings taken at commissioning
Service lifeNo fixed figure; judged by condition
ReferenceFAA AC 150/5340-26 · AC 150/5345-47 · ICAO Doc 9157 Part 5
Generic lifecycle. Selection criteria, test intervals, replacement policy and disposal rules depend on the airport, the manufacturer and local regulations; follow the site asset-management and safety procedures.
Entry 30 · Transformer replacement Full Index · Division 09

Frequently Asked Questions

Q1What is the lifecycle of a transformer in AGL?

The stages a series isolation transformer passes through: selection, installation and commissioning, operation, maintenance, replacement, and finally disposal with the record closed. Records carry information from one stage to the next.

Q2How long does a transformer last?

There is no fixed figure. Service life depends on the quality of the unit, the environment, the loading and how well it is maintained, so condition shown by inspection and testing, rather than age alone, decides when it should be replaced.

Q3Why record readings at commissioning?

They form the baseline. Later insulation and continuity readings are compared with them, so a slow decline is seen as a trend long before the transformer fails.

Q4What shortens a transformer’s life?

Moisture in the pit or connectors, heat, electrical stress such as an open-circuit secondary (for example a disconnected lamp lead), mechanical damage, and poor connections. Good pit drainage, sound connectors and prompt correction of faults extend it.

Q5How is the end of life recognised?

When tests no longer meet the specification, the unit is physically damaged, faults recur after the leads and connectors have been corrected, or a suitable replacement is no longer practical to maintain. Follow the site policy and the manufacturer’s data.

Q6What happens to a transformer that has been removed?

It is kept for examination if the cause of the fault is unknown, then disposed of or recycled under the environmental and site waste rules, with the manufacturer’s data checked for any hazardous materials in older units, and the record is updated to show the change.

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