Afternoon all,
How do i solve these two questions, Feel like am missing something simple. doing my head in lol.
I need to learn the calculation for them both, I am struggling to work it out.
1.
Insulation resistance has been tested on five new lighting circuits in an existing large...
Hi All, hope your all well.
I was hoping if I can please get some advice in regards to SWA. In Particular using SWA as CPC. Cable size 95mm2
I have a table for SWA which shows various information, in the last two columns it shows the "resistance of steel armour under fault conditions at 70...
Hi
I am a current student studying to become an electrician and a question has thrown me. I'm wondering if someone could help, there is a question on one of my home work books. "complete the following table assuming the resistors are connected in parallel?" the example I will give is R1 is 120...
Hey, I'm an electrical engineer in training and i was wondering how you could calculate the total resistance in a series-parallel circuit? I attached a picture of what it looks like. If it's to any help resistor 1 is 2, r2 is 3, r3 is 4, r4 is 5 and r5 is 6 Ohm. Thanks for any help
Boffins of the electrical world ... How can I calculate the resistance of 48m ring 2.5/1.5 .. with a 8m spur .. I can quiet easily do this without a spur in the equation but , my test papers require my doing so with an 8m spur. . how does this affect the zs tests ... Thanks v much ...
Hello
I am trying to calculate how long a car battery will last for which is 50ah, 12v. Running a 20watt device, 240v, turned on 24hours a day, how long would this battery last?
Any help appreciated
thanks
Hi all.
Been bugging me.
I think there is a way to calculate how fast a particularly rated RCD should trip (rather than measuring) but I can't remember how to do it ?
e. g. If I was designing an SWA submain fed from a TT earthed installation and I needed to install say a 300mA TD RCD to...
hello
1.is that acceptable if i do only Zs test last point of the lighting circuit and on scoket!
instead of measure R1+R2?
i can caluclate R1+R2 ACTUALY!
ZS-ZE=R1+R2 is it acceptable to write the value on certificate?
2. as i know the maximum Zs by rcd (rcbo)protected circuit 1667 ohm...
Hi again!
Which value is best to record in a certificate or report, a max measured or a calculated Zs?
I know Sparkies who do it both ways, but personally I take measured values at all the points of utilization to find the highest, then I calculate Ze+(my highest R1+R2) for the circuit and...
Yeh so thought I would check the main fuses and still can't tell what rating they are. I did contact the man from the DNO who said no hurry the next few months will do. @Leesparkykent he did say there are no penalty charges right now but come April there will be. We spoke with the energy...
Errr I am going to contact the guy in the letter. This is not a new supply they have been supplying the place for 30 years to my knowledge. But do they really expect me to calculate the load on maybe 70 DBs and then apply diversity to 66 different businesses??? Bit of a tall order unless I am...
I am trying to select a suitable conductor size from Fig 4D1A of the BS 7671 Book, and am encountering a problem because the circuit does not conform to one Reference Method. The circuit conductors leave the distribution board in wall mounted steel trunking, then run through some steel conduit...
Hi
I have a question regarding switch boards and distribution boards. We have an existing switchboard and we want to use four spare ways in this to feed three new tp & n distribution boards. One for lighting one for small power one for security services. My question is what calculations have to...
Good evening, i would like to know if someone knows how to calculate the time that would take to a solar panel of this kind Rotola in su pannelli solari produttore-Celle solari, pannello solare-Id prodotto:60489237141-italian.alibaba.com -...
I'm getting conflicting information regarding parallel resistors. I originally thought the below was how to calculate total parallel resistance
1. Rt= 1/R1+1/R2+1/R3
2. 1/Rt
However in my pre exam workbook it says to
1. Calculate Rt as 1. above
2. Find the lowest common denominator
3...
Hello there everyone, I've dead tested some ring mains on a job recently but unfortunately I didn't do my measured end to ends. The circuits only have two spurs on each.
I have my R1 + R2's, it was wired in 4mm T and E so the earth is obviously 1.5mm.
For example, if one circuit measured...
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