# total

1. ### How do i calculate the total resistance in a series-parallel circuit?

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
2. ### How to work out the total design load to find my swa cable size

Hi all I am having trouble trying to work out the total load and swa cable size. I have 10 circuits in a outhouse 40 meters from the mains power supply 1 x lighting with 10 lights, 1 x lighting with 10 lights. 1 x 2.5mm radial for 2 heaters, 1 x 2.5mm radial for heater. 3 x 2.5mm socket rings...
3. ### Total amps potential

hi all, Quick question I hope you can help me with, it’s to do with VIR triangle, and in this case how many amps pass through the circuit.. so.. If a human touches a circuit with 100,000 ohms resistance of the skin, and the voltage is 240 volts, does this mean the individual gets hit with...
4. ### how much total load in KVA

A client wants five new commando sockets, seeing as you cannot apply any diversity to the commando sockets would i be correct in saying the below will need to assume a maximum consumption of 96a from a 3 phase supply, so as a bare minimum the power supply specific to these circuits would need to...
5. ### total ecu meltdown car broke., dead.

just a weird one here. driving along, slow, in traffic, suddenly warning comes on " tryepressure system fault", then power steering fails, then IBIL roigh sensor fail" then RBIS left sensor fail, then engine stalls, won't restart. stuck in left lane of dual carriageway, hazzards on but still...
6. ### Uk total maintenance engineering Ltd

Anybody heard of these people? I've received emails offering exclusive contract works in my area on a contract they claim to have? Looks and smells like a scam to me but wanted to know if anyone else has heard about this?
7. ### excel formula Help

hi all small formula issue can anyone help got the basics can add, multiply, ect copy columns, but need a multiple column (sum) entry. Row a item £ sorted b total £ sum of h-P (sorted) H-P x a = B all good Column 1-200 some headings but overall so I need H1 - H200 column H x A But for the...
8. J

### Cooker diversity with SEPARATE oven/hob

Hi all, Looking at replacing kitchen. Current setup is 2.2kw oven, 5.6kw hob.. total = 7.8kw on 6mm cable, back to a 40a breaker. The current cable run is short.. 2m from CU, in breezeblock/plaster.. 2m clipped direct, to a 45a switch (for oven in tower).. 3m spurred from that, on...
9. ### Smart meter problem - outside UK

Smart meter installed. The electricity supplier provides an hourly analysis of electricity consumption on their website. The hourly consumption (kwh), except for the odd anomaly, appears to reflect what is used, but the daily total (also kwh), which is used for billing, appears to be an entirely...
10. ### Update: Total number of thread views shown on forum homepage! WOW!

If you visit the forum homepage (HERE) on a laptop/pc or tablet in landscape view, you'll see the total number of thread views for each forum category. Note that this isn't the total number of actual hits. As once you've viewed a thread, it wont keep counting you if you refresh the page.
11. B

### Overload or what ?

I got a call from a lad who runs a snack shop asking why his fuse kept 32 amp fuse kept tripping . I went to the shop to have a look he has a total of 20000 watts (100 amps )on at one time with fryers, hot plates ,grills etc ! All single phase . Having little experience myself as a spark I...
12. B

### Domestic Cooker Advice ? Ring main or dedicated circuit ?

Hi All My trusty old SMEG fan oven has finally died and i have been offered a replacemnt, brand new, never fitted at a good price. My current oven just has one rting - 3Kw (it has top/bottom/fan elements) and is just fed off a 13a plug of the main circuit (for about 12 years when i had new...
13. ### 3 phase cable selection and protective devices

Hi everyone. I'm after abit of help calculating cables sizes and protective devices for a 3 phase DOL motor. I haven't worked on 3 phase equipment for many years and 3 phase calculations is as far back as college so please excuse my ignorance on the subject and not knowing answers to perhaps...
14. C

### Domestic RCD total load vs MCBs

Hi all again. Enough with helping my friend and back to the main thing, which is back to studying. I am working on my final assessments (practice for my final L3 exam). Big 2 story house with the following requirements (protected devices given accordingly and installation method C, clip...
15. F

### Total load on distribution board

Hi im looking for someone to help me understand the total load that can be pull from a dis board. Ie: I have 3phase dis board on a 250amp breaker. The board is filled with mcbs of mixed ratings. However if I add the rating of each MCB together it far exceeds the 250amp breaker on the board...
16. P

### Domestic how do you work out maxium demand

can you show me how to work out maxium demand on a lighting circuit with ten lights on the circuit please
17. M

### Help with Oven Circuit.

Have an existing oven circuit 6mm2 twin & earth from the consumer protected by a 32a mcb goes to a cooker control switch, then 6mm2 from the switch was hardwired in to previous oven. Just bought a brand new oven (single oven that fits in cupboard under worktop) specifications are 2.3kW total...
18. R

### fuse question

hi guys, another question i need some help with. If the supply cut out fuse is a 100 A BS 88-3 device. why is it permissible for the total load to be greater than the main fuse rating? thanks
19. S

### Socket extension question - max amps

This has no doubt been asked often by non electrical minded folk like me but when a socket extension says maximum 13amps, does actually that mean 4 plugs fitted with 3amp fuses like desk lamps etc (or 5a+5a+3a) or does it go by the actual amps of the equipment and you could have say 6 plugs with...
20. S

### Domestic New assumed Current Demand of Installation

OMG!! can somebody please point me in the right direction because i am sure that i am looking in the wrong section of the REGS book... here is my question... Explain with reasons the New Assumed Current Demand of the Installation? My answer is this... For economic and reliable design, the...
21. B

### Domestic RCBO noise

Hello All. I have recently rewired a house, and fitted a TD-Line CU (main switch and all RCBO's). All has been fine until now, 1x 6a RCBO for the kitchen and TV room lights has started making a sort of buzzing/humming noise. I haven't heard it myself but the client says that it isn't very...
22. K

### Commercial 3 phase sunbed

Hi all Can you please help me with the below: i have 5 sunbeds thats 13KW per bed so 65KW in total (all 3 phase) + lighting, sockets etc all approx 3KW(SINGLE PHASE) Total of 68KW I need help with calculating total maximum power in kVA that i need for the above I tried to calculate it...
23. R

### VAT on Solar System

Forgive me everyone. New to this. How is VAT charged on A Solar PV system? If the system had 20% VAT put on by the supplier that sold to the installer... Where is the 5% calculated from by the installer when billing the client? Cheers
24. ### Upgrading existing installation

My MCS assessment site was 10x235w Conergy Mono panels with a sunny boy 2500HF on the roof of a south facing lean to extension. I havent yet notified the installation yet as I only got my MCS 2 weeks ago and the customer wants me to upgrade it to maximum, by installing panels on the upper roof...
25. B

### Pricing partial rewire( is it not to much)

Hi! I am pricing 3 bed flat in a block. Some circuits are existing will be not replaced (clients wish), kitchen circuits are new.Cables to be run in floor, wall, ceiling dwellings, everything is in concrete and bricks. Price is just for labour, no materials. Am I not charging to much?!?! Job is...
26. Z

### Domestic UPS Battery Run Time

I need some calculation on based of following findings: UPS rating = 1200 Watt Battery Rating = 1300 Ah Total Connected Load = 1000VA Operating Voltage = 240 V Can anyone please calculate for how long battery will provide power to the load ( i mean run time) ? Please show full...
27. W

### 3 phase upgrade

hi guys , i have to install new 3 phase cable to mushroom sheds and am not full sure off the size of cable i need. i have worked it out that i need 5 by 25mm swa. the cable run is 70 meters long and will be buried in the ground and will be ran with 5 other cables of the same size as there are...
28. ### can someone please confirm my working out, just for piece of mind.

please can someone confirm my working out of a annual return, as this is my first quote and just need confirmation that i have done it right. the system is a 22 panel 180W bp mono system and i am assuming the customer will be exporting 50% 22 panels x 180W =3960W or 3.96kW this will...
29. ### Cables in parallel formula

Hi Guys Quick one for you. A cable that is 25M long and has a resistance of 2.3 m ohms/M ( milli ohms per metre ). A second Identical cable is to installed in parallel with this conductor. What is the total resistance of the two conductors connected in parallel? 1st conductor: 25 x 2.3 =...
30. W

### ring circuit test

Hi all just wanted to confirm as got the nic man and anything that comes up, want to be confident in the answer. Am i right saying that the r1 & r2 reading on a reading circuit should be ruffly the quarter of the end to end readings added up ie L2L=0.26 N2N=0.26 L2L=0.43 TOTAL = 0.95...
31. M

### Lcm, booster, photo cell key switch

Hi Done tube work wired lights and photo cell, the key switch, Lcm and power booster done by another guy, switched on lights ok but they are very dim and take 1 hour to warm up, photo cell not working? Around 13-14 lights on a long run, if the lights were from the board via a key switch things...
32. S

### working out Kva etc!

Hi guys n gals, wondering if anyone knows the best method of working something out: if ive got a 3 phase supply, rated at 45Kva then how many amps do i have in total and per phase? does square root of 3 come into anywhere? also be handy to have the above solved and equated into KW's as...