Transformers failing

[bernardgreen]

It sounds to me as if he didn't use transformers at all. Transformers don't often fail. He has used switch mode power supplies, sometimes wrongly called electronic transformers (there is no such thing).
Get real transformers, or better still go for 240 volt LEDs.

Even better go for a wound transformer to supply around 9 volts AC, rectify and smooth to 12 volts DC and use this to feed 12 volt lamps with LED elements and constant current drivers..

It much easier to produce the controlled current that a LED element requires from a DC voltage of 12 volts than from an AC voltage of 230 volts.

Some 230 volt AC LED drivers do not provide constant current but instead provide pules of current that average out to the be the nominal constant current for the element. The pulses can be as high as ten times the nominal current. ( some very cheap one have even higher current pulses ).

This makes the LED appear much brighter but at the cost of shortening the life of the element. These lamps also produce light pulsing 100 times a second which can have serious stroboscopic effects when rotating machinery is being illuminated.

 

[London12345]

Based on information on this forum and other research. Just wondering if people can give an opinion on the below statements. Reason being I think the electrician that installed the lights should have informed me to the types of transformers used, and because they are failing less than 1 year after installation should replace free of charge.

1. The transformer is a very critical component of the light fitting. The build quality of the transformer will impact its life span and its replacement can cause damage to plasterwork. Average costs of transformers vary from approximately £3 to £10. The cost is typically an indication of build quality.

2. The transformers used are Avenue 60VA Dimmable Transformer. Avenue is an own brand of a company called MEDLOCK, they are known as a budget brand.

3. Despite meeting industry standards. The construction of these devices is inferior when compared to other products, such as the Aurora 2.

4. As a result, these Avenue 60VA Dimmable Transformers will have a shorter life span when compared with other products on the market.

 

[bernardgreen]

A LED lamp has two items inside the case.

An LED element that converts electrical energy into light and heat.
A driver that controls the current flowing through the LED element

Very often a "transformer" is used externally to convert the supply VOLTAGE to a voltage that the driver inside the lamp requires.

[1] The critical item is to control the CURRENT through the LED element. The element is NOT a resistive load so controlling the applied voltage will not provide the best working conditions.

The build quality will affect the life span of the "transformer". The compatibility of the "transformer" to the lamp in term of voltage, waveform shape, current and operating frequency will affect the life span of the "transformer", the internal driver and the LED element. The overall compatibility of a system is determined by the design of each item and the selection of items that the installer chooses to use.

[2] No comment on specific brands without having access to full data sheet and specifications

[3] there are no "industry standards" for these devices. Many claim to meet the safety standards of the countries where they are permitted to be sold. Some of these claims can be contested.

[4] If the specified item is used with non compatible items then its life span may be considerable shorter than the achievable life span when used with compatible items.

 

[London12345]

Thanks bernardgreen. Any information helps.

 

[ban-all-sheds]

I recently had the whole house rewired.

I have replaced 4 transformers in the first 18 months.

they are failing less than 1 year after installation

Which must mean that ones you have replaced are failing.

Your electrician won't do diddly-squat about replacing power supplies you have installed.

 

[London12345]

Moved in April 2013. So I guess between then and now is approx 18 months (4 failed within this time). However, 3 of the transformers failed before April 2014 (less than a year).

The original transformers are the ones failing (Avenue 60VA Dimmable Transformer) not the new ones (Aurora 2).

 

[winston1]

Based on information on this forum and other research. Just wondering if people can give an opinion on the below statements. Reason being I think the electrician that installed the lights should have informed me to the types of transformers used, and because they are failing less than 1 year after installation should replace free of charge.

1. The transformer is a very critical component of the light fitting. The build quality of the transformer will impact its life span and its replacement can cause damage to plasterwork. Average costs of transformers vary from approximately £3 to £10. The cost is typically an indication of build quality.

2. The transformers used are Avenue 60VA Dimmable Transformer. Avenue is an own brand of a company called MEDLOCK, they are known as a budget brand.

3. Despite meeting industry standards. The construction of these devices is inferior when compared to other products, such as the Aurora 2.

4. As a result, these Avenue 60VA Dimmable Transformers will have a shorter life span when compared with other products on the market.

1. They are NOT transformers. You cannot get transformers that cheap.
2. They are NOT transformers.
3. Certainly inferior to transformers.
4. They are NOT transformers.

 

[London12345]

They are definitely transformers.
- Auroura 2 12V 60W Dimmable Transformer costs £6.50 (was £11) from Ryness (http://www.ryness.co.uk/products?searchTerm=transformers).
- Unsure how much Avenue 60VA Dimmable Transformer costs.

 

[bernardgreen]

They are definitely transformers.
- Auroura 2 12V 60W Dimmable Transformer costs £6.50 (was £11) from Ryness (http://www.ryness.co.uk/products?searchTerm=transformers).
- Unsure how much Avenue 60VA Dimmable Transformer costs.

They are definitely called transformers but the only true transformer shown on that page is this one

http://www.ryness.co.uk/12v-300w-single-tap-transformr

 

[ban-all-sheds]

Whatever they are called, or really are, is irrelevant.

As I see it this is the situation.

OP had a rewire done, electrician fitted some [THINGS].

These [THINGS] began to fail after a short time, the OP replaced them with different ones.

Now 18 months down the line he is thinking whether he can do anything about the fact that the electrician chose and installed the [THINGS].

 

[London12345]

ban-all-sheds you have accessed the situation well.

 

[securespark]

London, have you tried talking to the [THING INSTALLER] about replacing the [THINGS]?

 

[London12345]

Have discussed with installer, but he won't take responsibility for the transformers (Things) installed. Even through in the rewire and fittings contractual agreement, fittings were provisional and hence should have been agreed. The installer says I choose a cheaper transformer (thing) from 2 options, which was not the case.

Hence, I have had to get independent people in to replace the transformers (things) when they fail.

 

[ban-all-sheds]

The installer says I choose a cheaper transformer (thing) from 2 options, which was not the case.

But which you can't prove.

However - even if you did choose a cheap option he is still responsible for replacing them if they fail unreasonably quickly. A warranty is a warranty, and if a choice is offered he should offer a choice between items for which he is happy to take warranty responsibility.

My concern though is that the time has now passed - he might argue that the items are too old, and he might argue that the other people you got in did something to cause the failures.

You will probably not get anywhere, but it's worth complaining to his Competent Person scheme organiser. You might not be the only customer he has treated like this, and if they get multiple complaints they might do something. It's worth the cost of a stamp.

 

[eveares]

Not sure what you mean by overloaded.

An overloaded transformer is when a transformer has a load grater than what it is rated for. (i.e. A single 50w transformer running 2 50w lights)

On a more serious note, transformers can fail if they get to hot such as by having insulation around them.

I personally like these from tlc: http://www.tlc-direct.co.uk/Products/LTYT50.html