12v light delay question

[brodders97]

Hi all,

I’m doing my bathroom up currently and in the process, I want to look at the delay in one of the lights

3x downlights are 230v, one is 12v as it’s got an Integrated fan.

I know the couple second delay is due to the voltage dropping to 12v, but is there any way to eradicate this? It’s really annoying when you walk in, then turn the lights on to have 3 come on and one come on later.

Thanks

 

[pc1966]

Some LED lights are like that, not sure why. Only option is to look at replacing the lamp (assuming it is replaceable) as you might find they vary from light to light in the same basic model (we have ne 50W flood that comes on a second late).

Only other thing is to look at replacing that unit with some other model to see if it is quicker, but I doubt that is value for money.

 

[brodders97]

Some LED lights are like that, not sure why. Only option is to look at replacing the lamp (assuming it is replaceable) as you might find they vary from light to light in the same basic model (we have ne 50W flood that comes on a second late).

Only other thing is to look at replacing that unit with some other model to see if it is quicker, but I doubt that is value for money.

Thanks for your reply, I recently got another 12v bulb to put in it, same issue. I was wondering if it was something to do with the power the bulb is compared to the transformer? I have no clue

 

[pc1966]

Thanks for your reply, I recently got another 12v bulb to put in it, same issue. I was wondering if it was something to do with the power the bulb is compared to the transformer? I have no clue

Sounds like the "transformer" feeding it is slow to come on. Typically these days they are not transformers as such, but switch mode AC-DC converters like PC power supplies, etc.

I have no idea if that is a separate unit and/or if a replacement would cure things to your satisfaction. It might, but equally it might be a waste of money is they simply are all like that.

 

[brodders97]

Sounds like the "transformer" feeding it is slow to come on. Typically these days they are not transformers as such, but switch mode AC-DC converters like PC power supplies, etc.

I have no idea if that is a separate unit and/or if a replacement would cure things to your satisfaction. It might, but equally it might be a waste of money is they simply are all like that.

Thanks again, I’ll see if I can do something with that, have a good weekend

 

[pc1966]

Just to confirm, all are LED lights? It is not a halogen one in the fan unit?

 

[brodders97]

Just to confirm, all are LED lights? It is not a halogen one in the fan unit?

3x are led, one was halogen originally which got replaced with led. Now it has the issue

 

[pc1966]

3x are led, one was halogen originally which got replaced with led. Now it has the issue

Interesting. Did you try a different brand of LED replacement when you tried replacing it?

 

[brodders97]

Interesting. Did you try a different brand of LED replacement when you tried replacing it?

I have yeah, I actually think 3 in total. First one was a cheap one I had lying around, second was from Screwfix can’t remember the brand. Third was by integral led

 

[pc1966]

I have yeah, I actually think 3 in total. First one was a cheap one I had lying around, second was from Screwfix can’t remember the brand. Third was by integral led

Drat.

Back to halogen?

 

[brodders97]

Drat.

Back to halogen?

May be an option. Just a quick one, I’ve been in the loft. The led is fed by a separate led driver. The led driver was 30W. As there’s no halogen it doesn’t need to be that big. So I swapped it for a 5W 12v driver.

The delay is now even longer. Do you think I need to go for a higher powered driver?

 

[pc1966]

May be an option. Just a quick one, I’ve been in the loft. The led is fed by a separate led driver. The led driver was 30W. As there’s no halogen it doesn’t need to be that big. So I swapped it for a 5W 12v driver.

The delay is now even longer. Do you think I need to go for a higher powered driver?

It is unlikely to be as simple as just the power level of the driver. My own bathroom as IP65 lights with separate driver that is only 10W or so and they are more or less instant on.

Sadly specifications like turn-on time are rarely given

 

[brodders97]

It is unlikely to be as simple as just the power level of the driver. My own bathroom as IP65 lights with separate driver that is only 10W or so and they are more or less instant on.

Sadly specifications like turn-on time are rarely given

That’s a shame, so much for being energy efficient. Thank you for your help

 

[marconi]

It may be the integrated fan and lamp fitting is a safety electrical low voltage SELV type operating from a special separate safe mains to SELV 12V power supply.
Both the fan motor and lamp are energised from the same power supply. If this is the case then during the start and run up to speed of the motor the so called starting surge current will depress the output voltage of the power supply. Only when the motor is running at speed is the output voltage sufficiently back to normal 12volts for the halogen or led to draw enough current for them to illuminate. Both types of lamp also have there own short period when they draw more current than there rated running current. The delay in lighting the lamp is due then to the motor start up surge and then the surge period for the lamp.

Solution - separate SELV 12V supplies of suitable power for fan and lamp (preferred) or one more powerful regulated SELV power supply for both (may or may not eradicate delay). But then you would be modifying a bought product designed to be safe which opens up a minefield of safety issues.

Post details of the integrated fan and lamp.

ps: led lamps have minimum voltage requirements too.

 

[pc1966]

Both the fan motor and lamp are energised from the same power supply. If this is the case then during the start and run up to speed of the motor the so called starting surge current will depress the output voltage of the power

Brilliant thinking!

 

[brodders97]

It may be the integrated fan and lamp fitting is a safety electrical low voltage SELV type operating from a special separate safe mains to SELV 12V power supply.
Both the fan motor and lamp are energised from the same power supply. If this is the case then during the start and run up to speed of the motor the so called starting surge current will depress the output voltage of the power supply. Only when the motor is running at speed is the output voltage sufficiently back to normal 12volts for the halogen or led to draw enough current for them to illuminate. Both types of lamp also have there own short period when they draw more current than there rated running current. The delay in lighting the lamp is due then to the motor start up surge and then the surge period for the lamp.

Solution - separate SELV 12V supplies of suitable power for fan and lamp (preferred) or one more powerful regulated SELV power supply for both (may or may not eradicate delay). But then you would be modifying a bought product designed to be safe which opens up a minefield of safety issues.

Post details of the integrated fan and lamp.

ps: led lamps have minimum voltage requirements too.

Great suggestion, however the fan itself is actually 230v. Its only the light that is on a 12v driver. It’s not one of the built in ones

This is the same one on Screwfix

Manrose 100mm Axial Inline Bathroom Shower Extractor Fan Kit With LED Light with Timer Bright Chrome 240V

Order online at NoLinkingToThis. Plastic. Chrome or white fascia with square external grille. FREE next day delivery available, free collection in 5 minutes.

www.googleadservices.com

 

[marconi]

I wonder then whether it is a feature of the LED lamps you have used. In our home the mains voltage GU10 LEDs which do not have a dimmer switch use non-dimmable lamps and they come on straight away. In one room we have 12 dimmable GU10 LED lamps controlled by a Varilight dimmer switch. On turning on all are off, then the same one after a few seconds illuminates and then the remaining 11 all come on at the same time. It seems it is not one delay produced by the dimmer - it has a soft-start feature which one might expect would cause a delayed power up for all lamps. It seems this one lamp is the 'dominant' load upon first switch on. The dimmer was switched on at the 100% setting. At lower settings there does seem to be some individual lamp delayed illumination but this does not 'replicate' your situation of simple on/off control.

You might do a simple check on the lamps to see if they are dimmable and if so swap for a non-dimmable type.

Please check the LED driver specification to see if there is a minimum LED load requirement. And find out if it has a soft-start turn on feature.

I'd check too that the fan and the LED driver have been wired in parallel across the incoming mains L and N and not in series and then across the mains.

 

[brodders97]

I wonder then whether it is a feature of the LED lamps you have used. In our home the mains voltage GU10 LEDs which do not have a dimmer switch use non-dimmable lamps and they come on straight away. In one room we have 12 dimmable GU10 LED lamps controlled by a Varilight dimmer switch. On turning on all are off, then the same one after a few seconds illuminates and then the remaining 11 all come on at the same time. It seems it is not one delay produced by the dimmer - it has a soft-start feature which one might expect would cause a delayed power up for all lamps. It seems this one lamp is the 'dominant' load upon first switch on. The dimmer was switched on at the 100% setting. At lower settings there does seem to be some individual lamp delayed illumination but this does not 'replicate' your situation of simple on/off control.

You might do a simple check on the lamps to see if they are dimmable and if so swap for a non-dimmable type.

Please check the LED driver specification to see if there is a minimum LED load requirement. And find out if it has a soft-start turn on feature.

Will do thank you.

The driver I swapped it for just said 15w on it. I’m assuming it meant 15w max? As in it can power 0-15w.

I’ve just ordered one that specifically says 0-10w, so maybe this will work.

Next time I’m out I’ll grab myself a good quality non dimmable mr16 light to see if this cures it too.

My SO doesn’t mind the effect, it’s driving me mad. You’d think it would be the other way round ay

 

[brodders97]

Just a quick one, my new driver arrived today, fitted and made no difference.

Once I got my glasses on, I did realise that the mr16 led bulbs I have are 12v AC, my driver of course is 12VDC. Would this make any/much difference?

 

[marconi]

Not that the lamp is ac. Some are dc which means one has to be careful which way they are plugged in to match the polarity of the supply.

It seems the delay is due to the driver - a soft start feature - intended to extend the life of LED lamps by not subjecting them instantaneously to the full supply voltage and current. You could confirm this by connecting the LED lamp across your car battery taking care of course not to short circuit the battery.

A conventional 230 - 12 Volts SELV transformer in lieu of the driver would probably light the lamp quickly. But you would have to purchase a SELV transformer suitably packaged for it be safe and suitable.

You might be better to delay the illumination of the other three so that they all turn on at the same time.

Are you a qualified electrician?

 

[brodders97]

Not that the lamp is ac. Some are dc which means one has to be careful which way they are plugged in to match the polarity of the supply.

It seems the delay is due to the driver - a soft start feature - intended to extend the life of LED lamps by not subjecting them instantaneously to the full supply voltage and current. You could confirm this by connecting the LED lamp across your car battery taking care of course not to short circuit the battery.

A conventional 230 - 12 Volts SELV transformer in lieu of the driver would probably light the lamp quickly. But you would have to purchase a SELV transformer suitably packaged for it be safe and suitable.

You might be better to delay the illumination of the other three so that they all turn on at the same time.

Are you a qualified electrician?

Thank you, I am yes. Is there something I can put in line with the other 3 Dow lights to delay them? Or shall I change them to 12v

 

[telectrix]

go to bathroom. close eyes. flick switch, count " 1,2,3", open eyes.

 

[marconi]

If it was me....I'd make them all 12V same wattage, make, Part No so you only have to keep one type of spare lamp.

After some experimentation - you could try each lamp fed by their own but identical driver or all lamps fed by one driver- to determine if one or other arrangement produces all on together.

Or you could fit a DIN 'delay on' timer to the current group of 3 using one of these:

RS PRO SPDT Timer Relay, ON Delay, 24V ac 0.3 s → 30h, DIN Rail Mount | RS Components - https://uk.rs-online.com/web/p/timer-relays/8966810

 

[brodders97]

If it was me....I'd make them all 12V same wattage, make, Part No so you only have to keep one type of spare lamp.

After some experimentation - you could try each lamp fed by their own but identical driver or all lamps fed by one driver- to determine if one or other arrangement produces all on together.

Or you could fit a DIN 'delay on' timer to the current group of 3 using one of these:

RS PRO SPDT Timer Relay, ON Delay, 24V ac 0.3 s → 30h, DIN Rail Mount | RS Components - https://uk.rs-online.com/web/p/timer-relays/8966810

Good idea about the delay on module, I could sort that. Although, obviously, I’d prefer to have them all instant as opposed to delayed

What do you think to using a standard 12v power supply? Such as the ones made by Puls, or similar

ML30.102 | PULS MiniLine MLY Switched Mode DIN Rail Power Supply, 100 → 240V ac ac Input, 12V dc dc Output, 3A Output, 30W | RS

uk.rs-online.com

I actually have one of these kicking around in the garage, don’t ask me where from

It seems most, if not all (that I can find) LED drivers have a built in soft start, so if I was the get a standard 12v power supply, issue solved?

 

[pc1966]

Good idea about the delay on module, I could sort that. Although, obviously, I’d prefer to have them all instant as opposed to delayed

What do you think to using a standard 12v power supply? Such as the ones made by Puls, or similar

https://uk.rs-online.com/web/p/din-rail-power-supplies/4246266

I actually have one of these kicking around in the garage, don’t ask me where from

It seems most, if not all (that I can find) LED drivers have a built in soft start, so if I was the get a standard 12v power supply, issue solved?

It is worth a try.

Such DIN rail PSU need to be enclosed as they are not suitable for open use, and the cables going in/out would need to be restrained so connections not stressed, but if that fixes your problem then a matching DIN enclosure and a couple of cable glands might be your next step!