Re: Finding a lamps arc voltage « Reply #1 on: February 21, 2022, 10:36:54 PM » Author: funkybulb
Arc volt is measured from two points at the lamp such as both ends of flourescent  tube while running.   Problem is domt expect starter to work on second lamp in series. Unless the starter is across both lamps at once.  As it takes about 85 volt to trigger the starter. The most I ever got lit is 4 tubes in series on manual preheat on 128 volt  Line voltage.
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No LED gadgets, spins too slowly.  Gotta  love preheat and MV. let the lights keep my meter spinning.

	Re: Finding a lamps arc voltage « Reply #3 on: February 22, 2022, 08:26:57 AM » Author: funkybulb
On preheat u can measure it by removing starter while lit.  And I use a modifeid starter with my meter probe leads soldered to starter pin. This allowed me do quick safe arc voltage check of fluorescent lamp  In a preheat fixture.
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No LED gadgets, spins too slowly.  Gotta  love preheat and MV. let the lights keep my meter spinning.

	Re: Finding a lamps arc voltage « Reply #4 on: February 22, 2022, 08:48:08 AM » Author: Rommie
The right test equipment helps, I use this, which can show both voltage and current on the same display. You just put the fork around one of the wires to the lamp and connect the black probe to ground. Yeah it's expensive, but I'm a test gear junkie, that's my excuse and I'm sticking to it
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Ria (aka Rommie) in Aberdeen
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	Re: Finding a lamps arc voltage « Reply #6 on: February 22, 2022, 06:50:39 PM » Author: Rommie
You could, but a safer way is to just connect the black lead to ground and then put the live (hot) wire to the lamp in the open fork. That will give you lamp current and voltage on a single display and you don't have to make contact with any live wires. It's an expensive piece of equipment, but it's useful for a lot of things. I wouldn't justify buying it just for this
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Ria (aka Rommie) in Aberdeen
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	Re: Finding a lamps arc voltage « Reply #8 on: February 23, 2022, 05:25:13 AM » Author: Rommie
Almost, as it's an AC inductive circuit then what you actually get is VA (volt-amps) which is apparent power and is always a higher figure. You need to multiply this by the power factor to get actual watts. Using this actual tester, the red (hot) probe would not be connected.
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Ria (aka Rommie) in Aberdeen
Administrator, UK & European time zones. Any questions or problems, please feel free to get in touch

"What greater gift than the love of a cat..?" - Charles Dickens
*** No smiley-only replies, please ***