Newbie says HELLO all !!!

Maverick here...

:signthankspin:

The thanks is in anticipation for all the assistance I will be asking for:  :Blushing

I am currently studying for EAL 4337/8 Initial Verification / Periodic Inspection & Testing. 

I am struggling a little with a couple of the questions mainly the calculation ones. I feel Im doing ok, but if its ok with you guys / girls I'd like to call upon your vast experience.

Anyway hoping to contribute in the future..

Cheers all.. Guinness

Welcome, we are always willing to help with homework questions providing you make a stab at them first.

Thankyou Roy 

Cheers Roy,

One question Im struggling with is 3 circuits have insulation resistance values of 100M ohms / 50 / 40 respectively..

I have 1 over 100 = 0.01 / 1 over 50 = 0.02 / 1 over 40 = 0.025 totally 0.055  (when tested together the overall value will  be?)

Im struggling converting this to M Ohms..

Getting to late off for a brain rest... think the answer is 18.33 but eh does anyone know if this is correct??

Ta.

Hi maverick, welcome to the nuthouse, the only ice here is in the drinks! 

Why hey do you think it needs converting? 

Maverick1 said:

One question Im struggling with is 3 circuits have insulation resistance values of 100M ohms / 50 / 40 respectively..

I have 1 over 100 = 0.01 / 1 over 50 = 0.02 / 1 over 40 = 0.025 totally 0.055  (when tested together the overall value will  be?)

Im struggling converting this to M Ohms..

Click to expand...

Do you know what the M stands for?

roys said:

Do you know what the M stands for?

Click to expand...

The reason for asking is that they are all in M Ohms and the answer is in M Ohms so the 6 zeroes in all the sums will just carry through to the final answer which will be in M Ohms, so you are as well just working with the 3 IR readings you have.

You have done your calc so far correct as in you have worked out the bottom line = 0.055. Now all you have to do is divide1 by 0.055 and you have your answer in M Ohms.

What do you get?

And the question I always ask myself is, does it look realistic given the numbers.  That helps make sure you haven't done something silly (doesn't always work).

Hi Sharpend / Roy, - the Sharpend the question asked "When tested together the overall value will be?"

and the given answers were 18M 5M 50M etc, so my workings out to this point = 0.055 wouldn't be the correct answer.

Hi Roy, yes I know what Meg stands for: It seems you have identified the last steps being I needed to divide 1/0.055 = 18M so cheers all for your help.

I must have missed that step somewhere couldn't find it in the 7671 or GN3 which I had been suggested to look in or its there and I simply can't find it...  :Salute

Maverick1 said:

Hi Sharpend / Roy, - the Sharpend the question asked "When tested together the overall value will be?"

and the given answers were 18M 5M 50M etc, so my workings out to this point = 0.055 wouldn't be the correct answer.

Hi Roy, yes I know what Meg stands for: It seems you have identified the last steps being I needed to divide 1/0.055 = 18M so cheers all for your help.

I must have missed that step somewhere couldn't find it in the 7671 or GN3 which I had been suggested to look in or its there and I simply can't find it...  :Salute

Click to expand...

Yip 18.18M Ohm is what I got, well done.

cheers Roy, you put me onto it... Ta.