How To Preventive Maintenance Of Transformer?

1. Oil level in the oil cap must be checked on a monthly basis so that it doesn’t drop below a fixed limit and hence avoid damage due to it.
2. Keep the breathing holes in the silica gel breather clean to ensure proper breathing action at all times.

Why maintenance of transformer is required?

A power transformer maintenance and testing program includes the following benefits: Increased safety, problems are detected before they are a hazard . Increased equipment efficiency, conditions related to transformer losses can be corrected. Reduced expenses, repair work can be properly scheduled.

What is preventive maintenance?

Preventive maintenance (PM) is the regular and routine maintenance of equipment and assets in order to keep them running and prevent any costly unplanned downtime from unexpected equipment failure . A successful maintenance strategy requires planning and scheduling maintenance of equipment before a problem occurs.

How can we prevent transformer failure?

The primary method of preventing this is high quality surge protection and regular maintenance of the existing surge protection system . The regular checks and balances of surge protection should involve annually checking the ground connection of the surge arrester. Connection should be tight.

How do you maintain oil in a transformer?

1. Oil level in the oil cap must be checked on a monthly basis so that it doesn’t drop below a fixed limit and hence avoid damage due to it.
2. Keep the breathing holes in the silica gel breather clean to ensure proper breathing action at all times.

How do you clean a transformer?

The windings may be cleaned with a vacuum cleaner, blower, or compressed air . The use of a vacuum cleaner is preferred. The compressed air should be clean, dry and should be applied at a relatively low pressure, (not over 25 psi.).

What is protection transformer?

The protection of a transformer against the overloads is performed by a dedicated protection usually called thermal overload relay . This type of protection simulates the temperature of the transformer’s windings. The simulation is based on the measure of the current and on the thermal time constant of the transformer.

What is transformer maintenance schedule?

They can be on a daily, monthly, yearly, quarterly, half-yearly, or yearly basis . Some transformer maintenance activities only need to be performed once in a 3 to 4 years interval.

How do you maintain a distribution transformer?

1. Sludge, dust, dirt ,moisture can be removed by filtration.
2. Oil when topped up shall be of the same make. ...
3. Insulation resistance of the transformer should be checked once in 6 months.
4. Megger values along with oil values indicate the condition of transformer.

What are the 4 types of preventive maintenance?

• Time-based maintenance. ...
• Usage-based maintenance. ...
• Predictive maintenance. ...
• Prescriptive maintenance. ...
• Hospitality & Restaurant Industry. ...
• Manufacturing Industry. ...
• Fleet Management Industry. ...
• Oil & Gas.

What are the 4 types of maintenance?

Four general types of maintenance philosophies can be identified, namely corrective, preventive, risk-based and condition-based maintenance .

What are the 3 types of preventive maintenance?

There are three main styles of preventive maintenance software: EAM (Enterprise Asset Management), CMMS (Computerized Maintenance Management System), and AOM (Asset Operations Management) .

What causes transformer failures?

The most common cause of failure of transformer is insulation failure ; it deteriorates due to heat, oxidation, acidity and moisture. Line surges such as switching surges, voltage spikes, line faults and distribution abnormalities.

How do you test a transformer?

To test your transformer, simply touch the red and black pins of your ohmmeter to the opposite ends of the transformer’s wiring . Read the display and compare the resistance on your ohmmeter to the resistance stated on the transformer’s data sheet. This is sometimes listed on the transformer’s enclosure.

How do you increase insulation resistance in a transformer?

If the insulation resistance of the winding is satisfactory but the dielectric strength of the oil is low then the treatment of oil in filtering and drying plant will improve its dielectric strength. If the insulation resistance of winding is lower than the specified value then the core and winding have to be dried.

Which type of oil is used in transformer?

Transformer oil is most often based on mineral oil , but alternative formulations with different engineering or environmental properties are growing in popularity.

Why is silica gel used in transformer?

The main function of silica gel is to control the amount of moisture available within a breather transformer . They are used to prevent any extra moisture from entering the transformer which may bring forth many unnecessary damaging effects to the transformer.

What is the Colour of transformer oil?

Generally, oil that is yellow, orange, or even somewhat red in color is fresher and will work as intended. As oil ages, it transforms to a brown or black color and its efficacy diminishes.

What is ppm in transformer oil?

PPM stands for Parts Per Million . It is used to measure the weight of moisture divided by the value of oil. The moisture content in oil lowers the insulating system dielectric strength that permits flashover to harm a transformer. For example, for mineral oil, a generally accepted maximum moisture content is 35 ppm.

Which relay is used in transformer protection?

Buchholz relay is used for the protection of transformers from the faults occurring inside the transformer. Short circuit faults such as inter-turn faults, incipient winding faults and core faults may occur due to the impulse breakdown of the insulating oil or simply the transformer oil.

What are the protection schemes for transformer?

• Buchholz Relay.
• Oil Temperature Indicator (OTI)
• Winding Temperature Indicator (WTI)
• Pressure Relief Device (PRD)
• Oil Surge Relay (OSR)

How many types of protection are there in a transformer?

• Overheating protection.
• Overcurrent protection.
• Differential Protection of Transformer.
• Earth Fault Protection (Restricted)
• Buchholz (Gas Detection) Relay.
• Over-fluxing protection.

How often should transformer oil be changed?

Dissolve Gas Analysis of transformer oil should be done annually for 132kv transformer, once in 2 years for the transformer below 132kv transformer, and once in 2 years for the transformer above 132kv transformer .

How do you check oil level in transformer?

To check the level indicator, remove the outside mechanism for testing without lowering transformer oil. After removing the gauge, hold a magnet on the back of the dial and rotate the magnet; the dial indicator should also rotate. If it fails to respond or if it drags or sticks, replace it.

How often should transformer oil be tested?

Routine testing of transformer oils and insulating oils on a regular schedule is an accepted industry practice. General and physical tests are suggested twice a year , dissolved gas analysis once a year, and Furan testing every 2 years for transformers in operation at least 5 years.