Repairing a Vintage IF Transformer
- Step 1 Removing the IF Transformer from the Radio Chassis: First, document the IF Transformer's connections so you know...
- Step 2 Calculations: Two calculations need to be performed before winding the new coil. First, we need to determine the...
- Step 3 Creating a new Secondary IF Transformer Winding: In my case, the secondary winding...
How do you de-energize a transformer for maintenance?
Maintenance in de-energized condition Before starting maintenance work, the transformer has to be disconnected from the network and earthed. When the circuit breaker and the isolator have been opened, they shall be locked in open position to prevent inadvertently closing during maintenance work.
How to troubleshoot the problems of the transformer?
Check timing. Short circuit in the control system on the secondary side. Remove the failure in the control system. Abnormal operating temperature measured by thermography. Local heating at the transformer terminals. Clean contact surfaces and retighten. Excessive cable heating. Undersized cables. Insufficient ventilation. High ambient temperature.
How to reclaim the oil of the transformer?
Reclaiming of oil is performed with the transformer in service (operation). The transformer is only de-energised for a few hours when the equipment is connected and disconnected from the transformer. If the oil is in good condition, except from particles present in the oil, filtering can be recommended for removal of the particles.
How to maintain the condition of transformer bushings?
Methylated spirit or easily evaporating cleaning agents can be used for cleaning. The condition of external conductor and bus bar joints of transformer bushings shall be checked at regular intervals because reduced contact pressure in the joints leads to overheated bushings etc. and may cause the adjacent gasket to be destroyed by the heat.
Can broken transformers be fixed?
It is possible some part of the external wiring has opened and could be repaired. If either the primary or secondary are open, internal to the transformer, then you could replace the transformer. If this is cost prohibitive then, unfortunately, you may have to buy a new one.
What causes transformer to fail?
A transformer can fail for a variety of reasons, but the most common causes include lightning strikes, overloading, wear and corrosion, power surges and moisture. Regardless of the cause, the result can be remarkable. Transformers contain mineral oil keeping the transformer cool.
Can a transformer be rebuilt?
Almost every transformer can be rebuilt after a failure. Many times the cause is a result of flash over, or a break-down of the insulation. The primary factor that may prevent a rebuild is damage to the transformer core itself.
How can you tell if a transformer is blown?
You can do a quick test for each winding for an open while the transformer is still connected in a circuit. Assuming you're using a cheap inaccurate ohm meter. Look for a reading of somewhere between one and about 10 ohms. If any winding reads higher than 10 ohms you have probably found a bad transformer.
How do I test a transformer?
You can test any transformer, including a phone charger transformer, using a multimeter. In output transformer testing, you use the voltmeter setting to check the output voltage while the transformer is connected to power.
How long should a transformer last?
30 to 40 yearsIn the U.S. alone, analysts say the average age of a transformer on the grid is 35 years old, near the end of its typical lifecycle. Under ideal conditions, transformers are expected to operate for 30 to 40 years, while industrial transformers have a life expectancy of just 20 to 25 years.
What makes a transformer stop working?
Usually, a transformer fails only after another part in the electrical circuit shorts to ground or draws an unusually high amperage. In these cases, replacing the transformer without first finding and correcting the fault will only cause the transformer to fail again.
What happens when transformer blows?
Failed transformers can be extremely dangerous and should only be handled by an experienced technician. A blown transformer can often result in fires or downed power lines containing large voltages which can easily cause electrocution.
How long does it take to repair transformer?
The average time to fix a transformer is between one hour to several hours. But, if there is severe or widespread damage, it can be up to several days or longer.
Do transformers have fuses?
The fuse is applied to the primary of the transformer and is used solely to prevent rupture of the transformer due to short circuits. It is important, therefore, to size the fuse so that it does not clear on system inrush or permissible overload currents.
How do you test a bad output transformer?
2:245:27Guitar amp tube output transformer testing How to D-Lab ... - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo you know it appears as though this is a good transformer. But now the best. Check is to put thisMoreSo you know it appears as though this is a good transformer. But now the best. Check is to put this transformer. On an impedance meter. Okay that's what this is this is a turns ratio meter.
What causes transformer to overheat?
Transformers are especially susceptible to overheating because as they step up or step down voltage levels between circuits, energy is lost as heat in the core and windings. That heat can build up damaging insulation and leading to transformer failure.
What are the common faults in a transformer?
11 types of transformer faults and how to protect the transformer from these faultsOver heating.Winding faults.Open circuits.External faults.Over fluxing.Earth faults.Phase faults.Inter turn faults.More items...•
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.
What causes transformer to trip?
Transformers are prone to nuisance tripping as a result of design flaws, operational conditions, improper relay settings, or otherwise. Transformers are a major component of substations and many times it is not affordable to have accidental outages, especially for bulk substations that serve large areas.
What happens when a transformer goes out?
Failed transformers can be extremely dangerous and should only be handled by an experienced technician. A blown transformer can often result in fires or downed power lines containing large voltages which can easily cause electrocution.
How to clean a transformer enclosure?
Horizontal surfaces should be cleaned with a vacuum cleaner. Coils cooling ducts should be cleaned using dry compressed air or nitrogen (maximum pressure 3 bar). If the transformer is installed in an enclosure, the enclosure should be cleaned like switchgear cubicles. Dust accumulation on the enclosure ventilation opening is an indication that an intemal inspection should be made.
What is the purpose of maintenance on a transformer?
The primary purpose of transformer maintenance is to ensure the internal and external parts of the transformer and accessories are kept in good condition and “fit for purpose” and able to operate safely at all times. A secondary and equally essential purpose is to maintain a historical record of the condition of the transformer.
Why should the conductor and bus bar joints of transformer bushings be checked at regular intervals?
The condition of external conductor and bus bar joints of transformer bushings shall be checked at regular intervals because reduced contact pressure in the joints leads to overheated bushings etc. and may cause the adjacent gasket to be destroyed by the heat.
Why tighten a bushing gasket?
Bushing gaskets; if leaks occur, tightening usually will help, if the gasket has lost its elasticity, it must be replaced. The reason for loss of elasticity could be excessive heating or aging, Cover gaskets, valves and gaskets of the tap changer. If there are leakages, bolt tightening will often help, Welded joints.
What is the control shaft on an off circuit tap changer?
The control shaft of the off-circuit tap changer is brought through the cover or the tank wall. The shaft end is provided with a handle, position indicator and locking device. When the tap changer is turned the locking device must be secured, because that assures that the off-circuit tap changer has been set to operating position.
How long does it take for oil to dry in a transformer?
Drying time can vary from one to two weeks depending on the transformer size, amount of insulation and initial moisture level in the insulation. Testing of oil in transformers should normally be performed 12 months after filling or refilling, subsequently annually on large distribution and power transformers.
Why is the transformer locked in open position?
When the circuit breaker and the isolator have been opened, they shall be locked in open position to prevent inadvertently closing during maintenance work.