Parmar Venture CWA ballast for US 175W Metal halide (and Mercury) Lamps
a recent ebay find that I am very pleased to have found!

its a 240V 50Hz CWA ballast! a 240V 50Hz CWA ballast is something I have wanted and have been looking for, for many years now so I was very pleased to finally find this one :) 

CWA ballasts are a type of ballast normally only found in the US and are very rare here in the UK and not easy to find! however Parmar did make them in 175W 250W and 400W Sizes and this is one of them

and as a bonus this is one for 175W lamps, shown here happily running a Westinghouse 175W life Guard mercury lamp :)

so I am also very pleased to have official 240V 50Hz 175W Ballast for my US 175W lamps :) (although a 150W SON choke generally works as a good substitute) 

I am also quite excited to try some alternative lamps on this ballast, as being a CWA ballast, its a fairly good constant current source, (ie regardless of what the lamp voltage does it will hold the lamp current steady at 1.5A~, compared to a choke type ballast, where the current will change depending on lamp voltage) 

so it may be just the ticket for running some 1.5A rated discharge lamps I have which have been difficult to run otherwise due to their unusual electrical characteristics (ie my 200W HO SLI/H lamp! which refuses to run on any 240V choke of any kind due to its high re-ignition voltage causing it to extinguish after a while)

I have to say I was not expecting just how big and heavy it is, its even bigger and heavier then my 400W MB/MBI choke!

its also constructed rather interestingly, its a transformer Core and Coil construction like a US ballast, but its been painted and has screw terminals with a base plate like a British/European ballast!

Parmar Venture CWA ballast for US 175W Metal halide (and Mercury) Lamps

a recent ebay find that I am very pleased to have found!

its a 240V 50Hz CWA ballast! a 240V 50Hz CWA ballast is something I have wanted and have been looking for, for many years now so I was very pleased to finally find this one :)

CWA ballasts are a type of ballast normally only found in the US and are very rare here in the UK and not easy to find! however Parmar did make them in 175W 250W and 400W Sizes and this is one of them

and as a bonus this is one for 175W lamps, shown here happily running a Westinghouse 175W life Guard mercury lamp :)

so I am also very pleased to have official 240V 50Hz 175W Ballast for my US 175W lamps :) (although a 150W SON choke generally works as a good substitute)

I am also quite excited to try some alternative lamps on this ballast, as being a CWA ballast, its a fairly good constant current source, (ie regardless of what the lamp voltage does it will hold the lamp current steady at 1.5A~, compared to a choke type ballast, where the current will change depending on lamp voltage)

so it may be just the ticket for running some 1.5A rated discharge lamps I have which have been difficult to run otherwise due to their unusual electrical characteristics (ie my 200W HO SLI/H lamp! which refuses to run on any 240V choke of any kind due to its high re-ignition voltage causing it to extinguish after a while)

I have to say I was not expecting just how big and heavy it is, its even bigger and heavier then my 400W MB/MBI choke!

its also constructed rather interestingly, its a transformer Core and Coil construction like a US ballast, but its been painted and has screw terminals with a base plate like a British/European ballast!

IMG_0425_4.JPG 387A1490.jpg IMG_0425_4.JPG IMG_0425_4.JPG IMG_0425_4.JPG
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Filename:IMG_0425_4.JPG
Album name:Lightbulbfun / My Lamps
Manufacturer:Parmar Venture
Type/Model:SHW17822245
Wattage:175W lamp, 205W inc Losses
Date manufactured:July 2007
Filesize:2469 KiB
Date added:17 Jan, 2022
Dimensions:1536 x 2048 pixels
Displayed:20 times
URL:http://80.229.24.59:9232/gallery/displayimage.php?pid=17349
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Lightbulbfun   [17 Jan, 2022 at 06:24 PM]
for those looking for one of these also, I have dropped a link to them in the ebay finds section on the forum Smile
FrontSideBus   [17 Jan, 2022 at 06:26 PM]
They've been in my watch list for a few weeks now tbh. I only have a couple of 175w lamps so I've been in no rush to buy one but I was thinking along the lines of 200w SLI/H. Interesting to hear you can't sustain them. I've ran them for ages on 150w SON chokes but then again my voltage is 250v lol.
Lightbulbfun   [17 Jan, 2022 at 06:30 PM]
well thats the interesting thing, I have found the 200W SLI/H HO, (the non HO lamps are another kettle of fish) will run on a choke, only if you have an ignitor in circuit, as the ignitor keeps the lamp going every mains cycle, cant imagine its very healthy for the ignitor! as you have probably noted the lamp voltage falls off a cliff and the current raises quite drastically, but if you remove the ignitor the lamp voltage will rise and the current will drop to a good level, but then the lamp will go out, I found this happened even if I cranked the Variac to 270V and/or used a series shunt capacitor for good measure, so it must have a pretty high re-ignition voltage! I measured this CWA ballast to have an OCV of 330V (its that high because it has to be able to strike metal halide lamps) so im hoping that will do the trick!
FrontSideBus   [17 Jan, 2022 at 06:58 PM]
IIRC I just prodded some flying leads from an SX72 across the lamp to get the HO going! The non-HO I just switch-started.
Lightbulbfun   [17 Jan, 2022 at 08:38 PM]
interesting! was the SX72 removed from the circuit once the lamp was struck or was it left in place? im not the only who had issues running a 200W HO either so its most interesting! Clicky indeed the Non HO lamps are fairly easy to run on a choke Smile (apart from the aforementioned current runaway situations)
FrontSideBus   [17 Jan, 2022 at 09:35 PM]
I'm pretty sure it was but it was a long time ago.
Lightbulbfun   [18 Jan, 2022 at 01:17 AM]
sounds like a good excuse to light it again! Smile perhaps fire up the GEC lamp along side it and grab some cool shots of sodium vapour absorbing its own light, I bet that would look quite spectacular in an SLI/H lamp Smile (I know a fellow collector who did so with a 60W GEC lamp but i dont think anyones done it with a Thorn cloverleaf lamp)

funnily despite owning a number of low pressure sodium lamps I have done the aforementioned demonstration of sodium vapour absorbing its own light, I must get round to doing it some day! as I am curious to see it with my own 2 eyes

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