Other Discharge lighting & Energy controllers

Hi,

I have been asked by a customer about a UK product called "Fluoresave". It looks very similar in functionality to the Energy controller, in so much that it is a voltage reduction unit for fluorescent fittings. The 2 differences I can see is that the fluoresave unit has a little jumper setting to change the percentage of voltage reduced (10%$, 12.5% or 15%). Also Fluoresave say that the unit can be used for any discharge lighting.

The unit I saw was a 4.8KW unit and it was running a number of SON fittings with magnetic ballasts.

Has anyone used the energy controller with SON's in this way?

If so, this would open a whole new market for us in the UK.

Thanks,

 

Hi Grahame - here's an "unofficial" response

There is no technical problem with the "concept" of using the voltage reduction devices for SON (High Pressure Sodium) lamps, and they generally work very well. But there is a fundamental difference in the timing control circuits required for SON compared to Fluorescent !

The Clipsal Energy Controller units drop down from 240V to 204V about 2 minutes after they detects a "power on event". This is to allow the fluorescent tube to start at full voltage, warm up and stabilise. When the voltage drops down, the lamp is warm and running nicely so everything will be OK.

But a SON lamp needs far longer to warm up - at least 5 minutes to allow the lamp to stabilise. Also remember the restrike delay for HID lamps, which need to cool down for 7 to 10 minutes before they will even attempt to restrike... so, the worst case is 10 mins + 5 mins = 15 mins, which is how most Autotransformer units for HID are designed.

This means that the Clipsal 5610 series units are NOT suitable for HID (SON and Metal Halide) lamps, as the voltage drop kicks in too fast. They might work, but it's not reliable - primarily due to the restrike problem, because it's unlikely the lamps will reliably strike at only 200 or so volts.

Perhaps you should ask the Product Managers to investigate a "HID-timed" version. If you can back it up with some sales projections, they might just decide to add a HID version to the standard range.

Here in Australia there's a pretty small market for SON lamps, as the "warm" light colour is not desirable (makes people feel hotter). The industrial market is dominated by Metal Halide. Whilst these MH lamps "may" be dimmed with Autotransformers, the lamp warranty will almost certainly be voided and it's certain that the lamp colour shift and all manner of other annoying issues mean that there's not much dimming done for HID sources of any form down under.

If they spend the money, they usually use a high efficiency, reduced wattage lamp instead. Typical is the Venture Uniform Pulse Start lamps instead of a traditional 400W MH. Or better, upgrade the luminaires and drop from 400W to (say) 250W which gives a far better result anyway. Not fiddling with input voltages is a far more "reliable" solution for Metal Halide, as the lamp life isn't comromised - remember in industrial work it's usually the labour to change the lamp that is expensive (cherry picker hire, etc), not the lamp nor the energy it consumes.

[ stops for a breath - see part 2 below ]

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[ rave continues ]

Note that the efficiency (efficacy) of fluorescent lamps improves when the wire-wound circuit is operated on reduced voltage - so for example a 15% drop in input voltage produces a 20 to 25% drop in power consumption. This results in a reduction of about 15% in light levels, which is a fair compromise and perfect for old installations designed for Halophosphate lamps (2900lm for a 36W tube) that have been relamped with Triphosphor (3350lm).

You'll notice that 3350 lumens minus 15% (by the Energy Controller) equals 2900 lumens... and that's the way the units are specifically designed. In Australia (and most other countries) there's heaps of old projects designed in the 1970's and 80's for halophosphate tubes, but the lamps are now banned under MEPs (minimum energy performance) standards so clients must use Triphosphor instead.

Mandatory triphosphor lamps doesn't actually save any power (both types of lamps consume 36W) but it does result in overlighting - so a neat 15% reduction in voltage drops them back to exactly the same light levels as were originally designed for

And due to the way that the inductive ballast/lamp circuit operates, the 15% reduction in light levels results in a very handy 20% to 25% reduction in power consumption (watts) ** [see note below]. So you kind of get about 10% for nothing !

But SON circuits are not the same - the drop in light levels is GREATER than the drop in power consumption. So, a 15% voltage (& power) reduction might result in a 30% reduction in light levels. The circuit drops in efficiency, and the more they are dimmed to worse it gets. Note that these are general comments only, as each type of HID lamp reacts slightly differently.

Anyway, with HID you must be extremely careful that the reduction in light levels is acceptable. See, in a commercial office you generally find that it's over-lit to hell and a 15% light level drop is irrelevant. But in industrial projects it's a lot different - the light levels are generally under-designed or borderline anyway, and there is no way that a 25 or 30% drop in light levels will be acceptable.

Must keep in mind, there's no use saving 15% power if your workers walk out because they cannot see well enough to do their jobs

So, step 1 is always to use a decent light meter and measure the lighting levels, then compare to the standards requirements. Devices like autotransformers do save power - but there is always a "cost" in the form of light level reductions that may or may not be acceptable.

Some companies promote autotransformers as a "one-size-fits-all" solution to everything, but this is not really correct in all situations and they can sometimes add unwanted complications. That said, when applied correctly they are a reasonable solution for tight-fisted clients who won't pay for a "proper" lighting solution

Sheesh - that was a long post... I hope it helps !!

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** NOTE - the 25% power saving ONLY applies to lagging power factor, which in Europe is often refered to as "Low Power Factor" (LPF) or "Parallel Compensated" (HPF). Many fluorescent circuits in Sydney and in Europe use Lead / Lag ("Duo" or "Series") correction, where 1 tube is LPF and the other lamp is series-corrected so that it has Leading power factor.

This combination does NOT give the same energy savings, and the best that can be usually acheived is about 12% for total Lead/Lag (Duo) combination. This is due to the way the series capacitor on the leading lamp affects the circuit when the voltage is reduced - basically, that tube does NOT get the same power-reducing effects from input the voltage reduction.

Further, there is numerous disadvantages of the Lead/Lag circuit, and even at rated voltage the lamp life is reduced significantly on that Leading circuit. When run on Energy Controllers, the capacitive (leading) circuit is completely off-spec, and there tends to be poor lamp life and other issues. Something to watch out for !!

 

If you are still interested my collague just installed a Florasave device in our office. You can SEE the difference in the lux output from the tubes.

Many people onsite are not impressed, but its saving a few euro.

 

Can you see the luxes?

Hi All
I've found it best not to tell the masses until they've lived with it for a few months, then present it in a positive light of how good the savings are for very little loss. Otherwise someone always finds a reason to complain in a large office.... we've even had complaints before the electricians got to the site! When the unit kicks into the savings mode, your eyes detect something has changed, but you can't necessarily say what, my experience is that unless you point out to people the change, they don't notice it. (this is all based on a set 15% Voltage reduction as in the Clipsal Energy Controller unit).

If you do the installation in conjunction with a bulk relamp the lighting levels will inevidibly go up, and you'll get uniformity improved when depleted and other coloured lamps are removed.
Regards Matthew

 

So professional. Thanks for posting. I really need to learn more. DIG.