What do you make of this....

[Electricalserv]

Went to a board change today. Weighed it up did usual tests. Went into kitchen......

Oven on plug into Kitchen ring and Hood wired directly into cooker circuit. Kitchen fitter - no paperwork!

What do you think guys. Refuse the board change unless they want remedials done?? or go ahead as its only the board that I'm touching..... They don't want a periodic.

Also I/R test on whole installation came back as 1.15 mohms very low, But still a pass....

Also 4 lighting circuits into one 5 amp fuse, house is massive with plenty of lights...burn marks all over fuse. They said lights always go off when the have parties at new year....I wonder why??? lol Absolute cowboy mess.

What do you guys think walk away or just do the board change?

 

[Silly Sausage]

Remember when IRing the board you're measuring all the circuits in parallel, so (assuming the juice isn't mashing my brains) the average reading (or each cct has the same IR ohmage) for each circuit will be 1.15Mohm * the number of circuits, eg 10 ccts = 11.5MOhm.

Someone let me know if I'm wrong so I can delete this.

 

[sparkinlee]

The IR reading for the board is looking at all the circuits in parallel - this means that the overall IR reading will be lower than each and every individual circuit reading.

Put another way, if the whole board reading is good, all the circuits must be good too. But if the overall reading is too low for compliance, it's worth checking each circuit separately because each circuit might be compliant, even if their combined reading is not.

I can't remember the exact maths right now, but that's the gist of it

 

[tony mc]

1/Rt = 1/R1 + 1/R2 + 1/R3 etc

So individual tests give say 10 M, 15M ,5M,20M,6M,12M, 12M

1/10 + 1/15 + 1/5+ 1/20+ 1/6 + 1/12 + 1/12

1/Rt = 0.1+ 0.067 + 0.2 + 0.05 + 0.167 + 0.083 + 0.083 = 0.75

Rt = 1/0.75 = 1.33 M ohms

So the lowest reading brought down the globle reading.

Hope this makes sence.

 

[sparkinlee]

1/Rt = 1/R1 + 1/R2 + 1/R3 etc

So individual tests give say 10 M, 15M ,5M,20M,6M,12M, 12M

1/10 + 1/15 + 1/5+ 1/20+ 1/6 + 1/12 + 1/12

1/Rt = 0.1+ 0.067 + 0.2 + 0.05 + 0.167 + 0.083 + 0.083 = 0.75

Rt = 1/0.75 = 1.33 M ohms

So the lowest reading brought down the globle reading.

Hope this makes sence.

Ah yes, I remember now...!

 

[telectrix]

by eck tony, thats a fair old bit of a sum for this time of night after beer. but i see the point. you can have 10 circuits, each 10M. in parallel they will read 1M. that's my level of maths at the moment.

 

[tony mc]

Bored and just had a curry which was very poor so waiting to see if I need to use the special location in a hurry !!!

 

[robsparky1975]

im sober for a change,will have to remedy that tommorrow.

 

[robsparky1975]

Imo they should have a full periodic inspection,pre change,and if anything comes up that would cause issues then its all extras,bonding included,dont be afraid to discuss any issues with them,remember that your the professional and can give as much advice as you need.

 

[SimpleSimon]

There's nothing wrong with these new ovens on plug tops. Especially the moulded ones because that's obviously how it's designed. We've just got to get used to not seeing these big clunky things

 

[Mr Mike]

Hope i have not missed something here, but could the appliance be gas with electric ignition.
As for the extraction on the cooker circuit,.... the motor must be huge

 

[Des 56]

... the motor must be huge

Its the larger version of this oneEmma Maersk

 

[Mr Mike]

Its the larger version of this oneEmma Maersk

Oooohh yyeeessssss

 

[Drew11]

My main worry is the oven on the kitchen ring. A 30amp fuse seems to have held it though, with no problems. Why anybody would plug the oven into the ring and wire the hood to the cooker cable is an absolute wonder. You check all the instrument of kitchen with the passage of time . Your problem is remove easily.

 

[wade88]

Hello

some ovens come with a plug, single ovens. The thing about them is, even if you add all the bits up (grill, oven) ...it's never really running at full tilt like, a kettle for example, which is why in the regs you work out the values using the first 10A and then 30% of the rest (for one case).

I saw a rangemaster spurred off the kitchen ring this week.

In the booklet with the oven it's total combined load is about 16kW. yes 16kW. And it has never tripped the 32A breaker, even though that adds up to 60 odd amperes.

!

69.56 amps in fact! thats impressive