I want to replace my Tridonic ballast with a new Vossoh Schwabe 163694 but the connectors are a bit different and it’s for my Philips PL-S 9W/01/2P bulb. The guy at the shop also gave me a capacitor with is it really needed? How do I connect the new Vossoh Schwabe ballast with my single G23 bulb.

The front holes on the VS ballast terminal work the same as in the Tridonic ballast. The top section (IDC slots, like what's used on Ethernet sockets) can work too, but it is intended for robotic luminaire assembly, and less convenient for manual connection

The ballast and lamp go in series :

L------Ballast-----------Lamp-------N

In the ballast terminal block, each 2 holes + 2 IDC slots are the same terminal. (left 2 holes + 2 IDC slots above them are one terminal, and right 2 holes + 2 IDC slots are the other terminal). So when you connect the ballast, connect your 2 wires to holes on different sides of the terminal block, so the ballast is connected in the circuit and the wires are not just shorted

If you are replacing the ballast inside an existing lamp, just wire it the same as the Tridonic was. (Why are you replacing it - The Tridonic does not seem to be damaged in any way ?)



The capacitor is used for power factor correction. It is critical in large setups which have many lamps on a circuit, to lower the load on the circuit and prevent pulling power with low power factor from the electrical grid. It does not have any effect on the operation of the lamp and ballast itself - They work the same with or without the capacitor

A capacitor in a luminaire connected with a plug is a problem - when you unplug it, the capacitor may remain charged and high voltage may be present on the plug pins. It's not dangerous (for 2uF capacitor the energy is very limited), but can still give you some shock if you touch the plug. Some capacitors have built in discharger that will discharge it in a short time, but not all of them

The capacitor, if installed, goes parallel to the line power :

L------Ballast-----------Lamp-------N
L------Capacitor----------------------N

Thank you so much for the reply you have saved me a lot of time and money I have just decided to look a bit further into the issue because of you remarks on the ballast and found that both my live and earth wires were shorting out that’s why the bulb didn’t start-up correctly (flickering) and in a video on Youtube it looked the same and the one guy said it’s the ballast the other one the bulb and because I am using expensive bulbs somebody on a different forum said rather buy a decent ballast with these types of bulbs and he recommended a Vossloh Schwabe L7/9/11.851 ballast. For now, I will keep the same Tridonic ballast because it has been loyal to me for the past 15 years.My device (light) is working again.

Both Vossloh Schwwabe and Tridonic are some of the best ballasts. The Tridonic can work for many more years

Looks like the wire was arcing to the luminaire metal parts, shorting out the lamp intermittently. Since it was on the ballast output, the current was limited by the ballast (to approx. 0.2A with a 7/9/11W ballast), so it did not become a full high current short circuit

The Earth connection of the luminaire metal parts prevented this from becoming a shock hazard

However, it should have tripped an RCD or RCBO breaker in your electric panel, if there is one for this circuit. It is recommended to protect most circuits with RCD or RCBO, and in some countries it is required by standards, at least for circuits that supply wall sockets

After many months I am back again still with the Vossoh Schwabe 163694. As you know I got the old lamp working again but I now want try a different project with the same Vossoh Schwabe ballast.
The wiring I confirmed with our local Vossoh Schwabe technical guys but when I tried it I saw a spark at the switch of the desk lamp and the breaker also tripped.Could the problem be with my wiring and I am currently using just a normal cheap PL 9W bulb to see if it works.
Thanks in advance

You appear to have two dead shorts there?, the choke is supposed to have just 2 wires, one in one out, if that blue on the switch wire is neutral then it’s a dead short! 

Thanks for the quick reply "the choke is supposed to have just 2 wires"? that's also what I thought meaning that I could use 2 bulbs on the same ballast eg channel 1 and 2 but someone else told me otherwise or I misunderstood him.
I am still confuse I have marked the 4 terminals on the ballast could you please guide me on the following items below,

Live from power supply
Neutral power supply
To Lamp
To Lamp
were do I connect the switch on

There no neutral to a choke, the twin ports are just for linking capacitors in, going back to the original photo above, if the left hand piece of twin flex is the incoming supply, and the right hand piece is going to the lamp, you just need to remove the 2 blue wires from the connector blocks and link them together if I’m looking at it right?

Yep that's how I see it as well. Plug it in like this and you have a direct short across the input feed 

Yeah, green switch wire to number 1, live out to the lamp to number 4, and your supply neutral and lamp neutral connect together in a block 

Thanks for the quick reply "the choke is supposed to have just 2 wires"? that's also what I thought meaning that I could use 2 bulbs on the same ballast eg channel 1 and 2 but someone else told me otherwise or I misunderstood him.
I am still confuse I have marked the 4 terminals on the ballast could you please guide me on the following items below,

Live from power supply
Neutral power supply
To Lamp
To Lamp
were do I connect the switch on

Just re-reading this again, you can’t run 2 x 9 watt PL on this choke, their not like a halogen transformer, if you want to run 2 x 9 watt PL lamps you then need an 18 watt series circuit, and that a totally different ball game altogether!
But you will then need to change the lamps to 4 pin PLs as the 2 pin will only house the 155/500 glow bottle starters in their base, these don’t work with series circuits, as you would need the 155/200 special series starters designed for twin circuits!
Sorry that this sounds awfully complicated  but this is the crazy world of fluorescent lighting circuits! 

The 9w PL-S lamps have FS-2 starters in their bases. The G23 2 pin 9w lamps are commonly used in series on a 13w PL-C choke.

Interesting, I wasn’t aware of that, but it makes sense as the FS2 does state 4 to 22 watts 

Good day all many thanks to all involved I picked up the project again today and got it working what a nice learning experience it was.
Sorry for taking so long but I had to test and confirm before responding.

The series connection on a common choke is possible only in 230V areas.

And take into account the "4..22W" is a bit misleading label on a starter, as it is still incompatible with many lamps with their power rating within that range (e.g. F13T5,...). What matters is the starter trigger voltage threshold vs the lamp arc (threshold has to be higher) and the ballast open circuit (threshold has to be lower) voltage.