test

[colly53]

Hi I have done a test on a lighting circuit and can't get my head round results.
Live--Live == 2.19 m ohms
Live-E ==== 99.9 m ohms
Also RCD tipping test at I ==400ms but does not trip
but at I5 trips at 14.7 ms
can anyone shed any light.

Thanks Col

 

[Geordie Spark]

geordie, you; re becoming almost human again. .g all that medicationmust be binnin

I binned my new vet on Tuesday - he failed the test - and got another new vet. The poor sod doesn't know what he's taken on - yet! .:devil2:

 

[GB.Kayak]

When you say LIVE - LIVE are we on about 3ph here or has you have not indicated a N reading do you mean L - N and if so what is your N-E reading.

Please give all readings and be clear as 'm ohms' would be 'mili ohms' so please represent your reading as you are taught M-ohms I would assume.

Where at and how are you taking your RCD readings...ie at the RCD or at a lighting point.

... ohm being the name of a person should read Ohm and therefore M-Ohms or more correctly MOhms surely?

 

[Darkwood]

... ohm being the name of a person should read Ohm and therefore M-Ohms or more correctly MOhms surely?

Surely not!.... the measurement ohm is an SI value and just because it is derived from Georg Ohm is here nor there, as you are referring to the SI value it is not neccesary to capitalise the 'O' ...

Putting MOhms would be wrong if not slightly confusing as you have lost the value of the 'M' pretext as it becomes now a part of another word..

If you are discussing 'Ohm's law' then a capital O would be required because you are refering to the man himself the guy who led a large resistance against electricity.

 

[DPG]

Surely not!.... the measurement ohm is an SI value and just because it is derived from Georg Ohm is here nor there, as you are referring to the SI value it is not neccesary to capitalise the 'O' ...

Putting MOhms would be wrong if not slightly confusing as you have lost the value of the 'M' pretext as it becomes now a part of another word..

If you are discussing 'Ohms law' then a capital O would be required because you are refering to the man himself.

Yep, the SI unit is lower case 'o' as Darkwood says. Mind you, Ohm's Law has an apostrophe as well !! Daz

 

[GB.Kayak]

Surely not!.... the measurement ohm is an SI value and just because it is derived from Georg Ohm is here nor there, as you are referring to the SI value it is not neccesary to capitalise the 'O' ...

Putting MOhms would be wrong if not slightly confusing as you have lost the value of the 'M' pretext as it becomes now a part of another word..

If you are discussing 'Ohm's law' then a capital O would be required because you are refering to the man himself the guy who led a large resistance against electricity.

Thanks d ... shall I put on the dunce's hat and go and stand in the forum's metaphorical corner?

One assumes ... dangerous I know from my earlier foray ... but, nothing ventured nothing gained ... that the full form should be Megaohm like Kilometre.

 

[GB.Kayak]

Surely not!.... the measurement ohm is an SI value and just because it is derived from Georg Ohm is here nor there, as you are referring to the SI value it is not neccesary to capitalise the 'O' ...

Putting MOhms would be wrong if not slightly confusing as you have lost the value of the 'M' pretext as it becomes now a part of another word..

If you are discussing 'Ohm's law' then a capital O would be required because you are refering to the man himself the guy who led a large resistance against electricity.

... that said, about Ohm vs ohm, it remains to be seen that in every other usage that I know of it is incorrect to use the short form multiplier of 'M' for Mega with the long form for the thing that we are multiplying ... you never see 'mmetre' in place of millimetre for example. Furthermore, to split the multiplier from the thing that we are multiplying in short or long form is incorrect vis a vis 'm m' vs mm for example. I do understand the difficulty of representing the omega character though it is allowed to be replaced by 'R' where it's reproduction as Ω is a problem!

 

[Darkwood]

It's an SI unit, it has a recognised formats that conform to standard keyboard options ... we can argue different examples all day but there is no rule of thumb as each can be unique as an example ...... all in all just jovial banter but you did pull me so I gave a response to reflect yours :49:

 

[GB.Kayak]

It's an SI unit, it has a recognised formats that conform to standard keyboard options ... we can argue different examples all day but there is no rule of thumb as each can be unique as an example ...... all in all just jovial banter but you did pull me so I gave a response to reflect yours :49:

Response taken in good humour, I learn't something new today ... not quite clear on what the middle clause above means.

 

[GB.Kayak]

Thanks d ... shall I put on the dunce's hat and go and stand in the forum's metaphorical corner?

One assumes ... dangerous I know from my earlier foray ... but, nothing ventured nothing gained ... that the full form should be Megaohm like Kilometre.

... I have just learnt another thing ... it is Megohm as the 'a' is dropped when prefixing a measurement beginning with a vowel ... Double Dunce! ;-P

 

[DPG]

Good point. And Kilohm. The English language eh! Daz

 

[trev]

the full form should be Megaohm like Kilometre.

If the suffix word starts with a vowel then the general rule is to drop the vowel from the end of the prefix word.
E.G. The equivalent of a million tonnes of TNT is a Megatonne but as we've seen, a million ohms is a Megohm.

 

[BES]

You say tomato , I say ********

 

[DPG]

You say tomato , I say ********

Killer-tomato?

 

[Geordie Spark]

If the suffix word starts with a vowel then the general rule is to drop the vowel from the end of the prefix word.
E.G. The equivalent of a million tonnes of TNT is a Megatonne but as we've seen, a million ohms is a Megohm.

That's my boy ...... :hurray:

A Geordie teaching English! Oh the irony!! . :wink_smile:

 

[trev]

See, yer alwaiz on aboot that posh skyule ye an me ma paid for. Payin off niw Fatha