SO/H and SOI/H low pressure sodium lamps on ignitor chokes? « on: November 12, 2021, 05:25:49 PM » Author: WorldwideHIDCollectorUSA
Since SO/H and SOI/H low pressure sodium lamps are often the predecessors of modern SOX low pressure sodium lamps, I often see people saying that SOI/H and SO/H low pressure sodium lamps are often interchangeable with SOX low pressure sodium lamps on the same ballasts. When I looked at the 85w and 140w SO/H and SOI/H low pressure sodium lamps, they have an arc voltage somewhere between 140v and 160v, which seems pretty high for operation on 220-240v ignitor choke ballasts. I would like to know if 85w and 140w SO/H and SOI/H low pressure sodium lamps are able to satisfactorily operate on the 220-240v ignitor choke ballasts that are intended for 55w and 90w SOX low pressure sodium lamps respectively or whether they really need high OCV HX autotransformer ballasts.
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Desire to collect various light bulbs (especially HID), control gear, and fixtures from around the world.

DISCLAIMER: THE EXPERIMENTS THAT I CONDUCT INVOLVING UNUSUAL LAMP/BALLAST COMBINATIONS SHOULD NOT BE ATTEMPTED UNLESS YOU HAVE THE PROPER KNOWLEDGE. I AM NOT RESPONSIBLE FOR ANY INJURIES.

	Re: SO/H and SOI/H low pressure sodium lamps on ignitor chokes? « Reply #1 on: November 12, 2021, 05:48:54 PM » Author: Rommie
The answer is yes and no. The 85W SO/H and SOI/H lamps both operate at 0.6A, whereas the 90W SOX runs at 0.9A. so they are not interchangeable. The 140W SO/H & SOI/H lamps are also 0.9A so could probably run on a 135W ballast, but these lamps were designed for leak transformers. Choke/ignitor circuits did not come in until SOX was well established. The highest wattage lamp of this type I have is an 85W SOI/H, which runs fine on the Philips L4045 ballast, as do the 45W and 60W versions. 35W and 55W SOX lamps also run fine on this ballast, but a 90W SOX lamp would not.
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Ria (aka Rommie) in Aberdeen
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	Re: SO/H and SOI/H low pressure sodium lamps on ignitor chokes? « Reply #2 on: November 12, 2021, 05:51:06 PM » Author: WorldwideHIDCollectorUSA
Would the 85w and 140w SO/H and SOI/H lamps have a hard time maintaining an arc on ignitor choke ballasts? For example, would a 85w SO/H or SOI/H lamp have a hard time maintaining an arc on a 55w SOX ignitor choke? In addition, would a 140w SO/H or SOI/H lamp have a hard time maintaining an arc on a 90w SOX ignitor choke?
« Last Edit: November 12, 2021, 05:58:42 PM by WorldwideHIDCollectorUSA »		Logged

Desire to collect various light bulbs (especially HID), control gear, and fixtures from around the world.

DISCLAIMER: THE EXPERIMENTS THAT I CONDUCT INVOLVING UNUSUAL LAMP/BALLAST COMBINATIONS SHOULD NOT BE ATTEMPTED UNLESS YOU HAVE THE PROPER KNOWLEDGE. I AM NOT RESPONSIBLE FOR ANY INJURIES.

	Re: SO/H and SOI/H low pressure sodium lamps on ignitor chokes? « Reply #3 on: November 12, 2021, 05:57:30 PM » Author: Rommie
Not sure to be honest, I've never tried. I don't have a 140W lamp as yet and I'm not about to risk the rare 85W ones when I have the correct ballast for them.
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Ria (aka Rommie) in Aberdeen
It'll be all right in the end, and if it isn't all right, it isn't the end

Administrator, UK and European time zones. Any questions or problems, please feel free to get in touch

	Re: SO/H and SOI/H low pressure sodium lamps on ignitor chokes? « Reply #4 on: November 12, 2021, 06:00:43 PM » Author: WorldwideHIDCollectorUSA
Maybe James can chime in on this subject.
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Desire to collect various light bulbs (especially HID), control gear, and fixtures from around the world.

DISCLAIMER: THE EXPERIMENTS THAT I CONDUCT INVOLVING UNUSUAL LAMP/BALLAST COMBINATIONS SHOULD NOT BE ATTEMPTED UNLESS YOU HAVE THE PROPER KNOWLEDGE. I AM NOT RESPONSIBLE FOR ANY INJURIES.