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Osram-GEC 400W MA/H Lamp A rare and rather interesting one this, I'm not 100% sure how best to run it at the moment, as the leaflet with it says it needs a special choke tapping; I am reliably informed that the lamp should be run at 4.2A rather than the usual 3.25A, some thought is going to be needed here..! It is shown running here on a normal 3.25A ballast, as I hadn't fully read the leaflet (oops) but that was only for 10 minutes to take the photos. Keywords: Lamps

Osram-GEC 400W MA/H Lamp


A rare and rather interesting one this, I'm not 100% sure how best to run it at the moment, as the leaflet with it says it needs a special choke tapping; I am reliably informed that the lamp should be run at 4.2A rather than the usual 3.25A, some thought is going to be needed here..! It is shown running here on a normal 3.25A ballast, as I hadn't fully read the leaflet (oops) but that was only for 10 minutes to take the photos.
Thorn_50W_Pearl_HPS.jpg DSC03340.JPG Osram-GEC_400W_MA-H.jpg Army_Bardic.jpg Wotan-Sox-Lamp.jpg
Lamp/Fixture Information
Manufacturer:The General Electric Company of England
Model Reference:MA/H
Lamp
Lamp Type:Medium pressure mercury lamp
Filament/Radiator Type:Aluminosilicate glass arc tube
Base:E40
Shape/Finish:Tubular, clear
Burning Position:Vertical cap up to horizontal
Electrical
Current:4.2A
Physical/Production
Factory Location:Shaw, Oldham
Fabrication Date:March 1960 (Date code RC)
File information
Filename:Osram-GEC_400W_MA-H.jpg
Album name:Ria / Mercury Lamps
Keywords:Lamps
Filesize:348 KiB
Date added:Jul 22, 2024
Dimensions:2245 x 1587 pixels
Displayed:26 times
URL:https://trad-lighting.net/gallery/displayimage.php?pid=81
Favorites:Add to Favorites

Comment 1 to 12 of 12
Page: 1

Sammi   [Jul 22, 2024 at 12:09 AM]
Looking forward to seeing this rare beast lit again.! Cool
Ria   [Jul 22, 2024 at 12:27 AM]
Indeed, someone said a 400W SON ballast run at a slightly lower mains voltage should work, so we'll maybe try that soon.
Sammi   [Jul 22, 2024 at 12:29 AM]
As the correct ballast is unobtanium, that's the best we can do.
Tuopeek   [Jul 23, 2024 at 10:36 PM]
Think I have the same lamp, although with more hours on it. The start resistor has a connection issue but the outer jackets incomplete vacuum means it starts fine. I hadn't realised the current differs and have run mine up on a standard 400w MB/U mercury ballast. It does look like you might be running that horizontal though Surprised but I'm sure you know you need a magnetic deflector for that.
Sammi   [Jul 23, 2024 at 10:38 PM]
We are running it horizontally, and it was designed for that without the deflector, hence the higher current.
Tuopeek   [Jul 23, 2024 at 10:46 PM]
Wow, thanks for the information Sammi, I need to find out more on this and check if mine is indeed the same.
Sammi   [Jul 23, 2024 at 10:48 PM]
The MA/H lamps are like hen's teeth, our other ones, which look the same, are the usual MA/V lamps, have a shufti at the etch.
Tuopeek   [Jul 23, 2024 at 10:57 PM]
Ah, that sounds rare right enough think it might be the MA/V I have.
Ria   [Jul 23, 2024 at 11:03 PM]
Yeah, the genuine MA/H version is rather a rare beast, apparently it has a hard glass arc tube so is more able to withstand horizontal burning, but from what I can gather, the genuine ballast for it has a different tapping, not sure Confused
Tuopeek   [Jul 24, 2024 at 10:38 PM]
I see what you mean, it looks more or less physically identical to the MA/V. Surprised Also see a mention to 'special choke tapping' for the MA/H but not 100% clear if that's on the 400w MA/V choke. Glad you have this in your collection I would have missed this otherwise
Sammi   [Jul 24, 2024 at 10:39 PM]
So are we.! Laughing
Ria   [Jul 24, 2024 at 10:44 PM]
@Tupoeek - I think there was a special ballast for it, but not sure. I'm guessing so, given the higher current requirement.

Comment 1 to 12 of 12
Page: 1