Helvar EL-FD Series dimmable ballasts - problems

Hi all

We are going absolutely crazy on a project that has the old Helvar EL-FD 2x36W dimmable fluorescent ballasts. The site is about 6 hours drive from our offices, so it's not easy to administer or test anything.

For you younger folk, these are a electronic ballast that's dimmable using Leading Edge phase chopping. These ballasts have been discontinued since about 2002, but this project had heaps of them already installed and we couldn't convince the client to change to 0-10V or DSI - plus there is a lot of work to add control cables, etc.

We installed a bunch of L5102D10 Pro dimmers, and they are acting VERY strangely. Basically they won't switch off or Dim properly... it's almost like the Triac is locking on, except that light levels go UP at about 50% dim setting, then goes down if you dim down or up from there.

We got one dimmer and a light back here, and it wouldn't work on the bench. But if we connect a 15W pilot lamp in series with the ballast, then the Pro dimmer works perfectly. We tried a 32IND but that wouldn't fix it.

We tried a L5504D2U and that will dim OK, but will not switch off (assume not enough load). Adding a relay fixed that on/off but makes a problem due to delay while Universal dimmer senses the load. We didn't try using the relay AFTER the dimmer, so unsure if that would be a good solution - anyway, the Universal dimmer detects the load as Leading Edge, but doesn't have enough current handlimng capacity for the project (we need 10A per channel).

Helvar thinks that Pro Dimming MIGHT be fixed by adding a Helvar Bottom Load. I cannot get technical info on these, but I am guessing they are some kind of resistive load that connects between Neutral and Dimmed Active and pulls the triac back to zero volts?

Unfortunately we cannot get a sample of these things to test, so would have to pay $90 each to import them from the UK, and THEN drive 6 hours each way to install and test... and if they don't work we'll be even more out of pocket

Anyway, has anybody had any experience with these ballasts and how to make them work properly on the Pro Dimmers ?

 

Maybe a pointer

Hi John,
I would have been interested to know if this problem applies to all the circuits, without exception, or if there are some which work, and some which don't. I think you are probably close to the truth when you assume that some sort of feedback causes this behavior, but what it is in detail, I cannot tell either.
Perhaps the following may assist a bit:

I encountered a very similar problem when dimming cold cathode (Neon) lights. This too is a little outdated technology. Some circuits worked just fine, but with a few circuits it was such that once you set them to anything near 100% output, you couldn't switch the circuit off anymore.
The only way to get them off was to physically disconnect (e.g. via MCB).
At the time I suspected the (Pro) dimmer to be the problem, and changed them around, and replaced them. That wasn't the problem though.
In this case it turned out to be one or more faulty transformers on the circuit. Once they were replaced, the circuits worked perfectly (to this day).

The way we got to resolve this was to disconnect parts of the circuit and try the lights essentially transformer by transformer. This identified the dodgy units, allowing for repalcements to be made.

I think in your case it is probably not feasible to do this, but maybe you can try to connect a couple of different lights on a specific channel, and see if there is are some which work. I would aim for about half the dimmer capacity, as too much or too little could result in flickering (based on experience on the same type of technology) with this type of load.

I have also worked with the same sort of ballast in the past, but the dimmers used there were a different brand. Those dimmers are basically indistructable, but also cost twice the Clipsal product.

Hoping that this may assist.
Thomas

 

Helvar ballasts

Hi JohnC

Yep, I have come across these ballasts and have also tried to dim them with a Pro series dimmer to no effect.

Seems to cause premature lapm failure etc.
The site we did is about 10 hours from our office.

I will PM you with more.

DB

 

None of the circuits on the site work. They also don't work on the bench either. An individual ballast will dim perfectly if a 15W incandescent load (eg: pilot lamp) is placed in parallel across the dimmer output.

A standard clipsal wall dimmer won't work. A 4ch Cbus Universal dimmer will dim properly, but when set to Zero Output the lamps flicker and try to start (probably the usual dimmer leakage currrent). The Helvar installation sheet includes (requires) a "bottom load" wired in parallel, but the site doesn't have these. We are unable to obtain a bottom load in Australia to test with, and are worried that importing some $1000 worth of euqipment is an expensive "trial" if after driving 6 hours both ways we find that that doesn't fix the problem.

In our project, the Pro dimmer will not switch off irrespective of the dimmer setting. It doesn't dim either - basically, the outputs are locked "on" as soon as they are connected to the Helvar ballasts. When in this "locked on" state, if we then switch in a 15W pilot lamp into the ciurcuit, the dimmer instantly starts working correctly.

But this is on a bench test with 1 ballast on one channel. We have no idea what will happen when 15 or so ballasts are connected - do we need 15 x pilot lamps, or will 1 be enough? We need to drive 6 hours to test!! And what can we use to emulate the pilot lamp, because that isn't much use as a long-term fix since the dimmers will fail when the pilot lamp fails.

Keep in mind - these aren't transformers or wire-wound ballasts, they are electronic ballasts that look just like a standard DALI ballast. However, the particular ballasts use 2 filter chokes on the mains input for RFI suppression. There is talk that these chokes start to break down over the years, and cause wierd interraction with dimmers. We know that the dimmers work fine on resistive loads, but not with this particular load.

The main hassle is that the client will not cough up for replacement of all the ballasts, and is blaming us for faulty C-Bus equipment. Another complexity is that it's a commercial project and the landlord (building owner) is the one who owns the ballasts and the main C-Bus system (existing). The tenant we are dealing with wants the existing ballasts to dim, and is paying for the control equipment (dimmers and wall switches).

Ballasts Data Sheet (60KB)
http://www.helvar.com/download.asp?id=EL-FD+datasheet;626;{675C3CA9-332C-45AE-8C51-5AD63245F1A3}

Ballast Dimming information (11KB)
http://www.helvar.com/download.asp?id=EL-FD+control+protocol;740;{B2D3CF7E-66FC-4332-9B2C-10CE9E3A56AD}

 

Hi John,

I've looked throught the data sheets (links you posted). From that I would say that these 'Bottom Loads' are essential. As are the 2 working chokes.

It is also evident from your reply that your problem is a lot more severe than the one I described.

I am wondering though about how these lights have been dimmed in the past? Surely, if this sort of ballast system has been installed in the luminaires, then there would have been some method for dimming? One would presume that this would have been via some of these massive Helvar dimmers, with analogue control input. The good thing about those dimmers is that they are quite hard to kill, as far as I know.

The point I am trying to make is, have you thought about going into the control side of the original dimmers (if all of my above presumptions are correct) and run them off an analogue output module?

Unfortunately, I can't think of anything else, and I think that you will need whatever componets, in working order, which are specified for this sort of 'electronic' ballast.

I truly wish you all the best to resolve this matter.

Thomas

 

Thanks all - no need for further replies, we are ripping the whole lot out and starting again !

---- background info below -----

The existing installation never had dimmers connected... they were included in the orignal specification documents but were never installed ! The original spec was for dimmers and daylight linking / constant light level control - but obviously somebody pulled a swifty and never installed the equipment that would make it work.

They did install a rudimentary C-Bus system (version 1) but it only operated some contactors as a master on/off switch. Therefore the client thought that they had a state-of-the-art and highly energy-efficient project, where in actual fact the lights ran at 100% and chewed heaps of power for the past 10 years !!

The daylight-linking systems like what was proposed never work anyway, and in fact the tenancy next door removed theirs a few years ago after many years of frustration. Our proposal (with teh Pro dimmers) was simply to "dim" the lights by 20-30% (fixed setting) in order to save power.

We found that across the 2 tenancies the ballasts are starting to fail anyway (towards the end of economic life). These ballasts are no longer available. Considering that the potential savings were marginal anyway, we've decided to leave the C-Bus relays but remove the dimmers.

All lights will be de-lamped to 1x36W with new Osram QTP ballasts. This will reduce power consumption from 64W to 35W per fitting (with coresponding drop in light levels, which were too high anyway. C-bus will be contrlled by the Alarm panel.

So, we got out of our problem, and gained a larger order !

 

Hello everybody,

Trust we are doing great today.

Can someone suggest an alternative ballast to Helvar EL 2X55IDIM?

I have been trying to get some EL 2x55iDim for some time now but I've not been lucky, so I am looking for an alternative.

Waiting for your response.

Thanks in advance