Maximum Disconnection Times

[Megawatt]

138-139 volts, at 252 volts (+5%) it is 145 volts.

That highest voltage I’ve seen is 130 to ground and where are you getting 138vac
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That highest voltage I’ve seen is 130 to ground and where are you getting 138vac

Your drawings are irrelevant that’s not telling us nothing

 

[Cookie]

130 volts would be the highest in a 120/208 system, not a 240 volt wye system.

The drawings are correct for the system being depicted.

 

[static zap]

Also got a post deleted in another thread for saying the stuff on Amazon made by China is often not safe to install.

Tricky tight rope - Negative opinions ..
( I'm older and just love moaning )
You get what you pay for, (and some local wholesalers risk a big hit , when they have to honour their returns policy)
Need to educate customers to spend more!

 

[Cookie]

Education is key. Which is why I spoke up. But shady manufacturers/sellers know people buy solely based on cost.

 

[Megawatt]

130 volts would be the highest in a 120/208 system, not a 240 volt wye system.

The drawings are correct for the system being depicted.

On paper is one thing, in the real world it’s a totally different world. Why the emphasis on exactly 138vac

 

[Cookie]

Due to Uo (138 volts) changing the disconnect time requirements.

 

[Megawatt]

Where's my post gone? I was sticking up for the forum!!!

I’m from the US and we don’t have those kind arrangements

 

[DPG]

I’m from the US and we don’t have those kind arrangements

I think there's some confusion between systems.

 

[Megawatt]

I think there's some confusion between systems.

DPG confusing is an understatement I don’t know if the OP is asking a question or trying to teach us. LOL

 

[Cookie]

Asking about the code's reasoning. And Megawatt- I fully get you!

 

[Megawatt]

Asking about the code's reasoning. And Megawatt- I fully get you!

Cookie we can sit here all day and pull reference form the BS 7671 and posting table 710 which is in the medical locations. What’s that about

 

[Cookie]

710? I had 41.1 in mind. I'm curious how those voltage cutoff values were derived.

 

[Megawatt]

710? I had 41.1 in mind. I'm curious how those voltage cutoff values were derived.

Yes I missed table 41.1 maximum disconnection times on page 55 as far as how are the voltages are derived starts with AC and DC theory
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Yes I missed table 41.1 maximum disconnection times on page 55 as far as how are the voltages are derived starts with AC and DC theory

I’m trying to learn the UK ways of doing electrical work

 

[Cookie]

Right, but for AC we have 120 volts and under at 0.8, 0.4 for 120 volts and over. Is any real harm granted in having 0.8 cover up to 150 volts?

 

[Cookie]

UK wiring requires that general socket and lighting circuits trip a breaker in a required amount of time based on the line to earth voltage.

 

[Megawatt]

UK wiring requires that general socket and lighting circuits trip a breaker in a required amount of time based on the line to earth voltage.

We can test breakers or RCDs but we can’t fix them if there are 1/10th of a second to slow, as far as I go if they trip I’m happy. I read your profile and I applaud you for wanting to learn but don’t just post things you are reading and asking why. I’m here to help anyone that needs it if I can. I’m going to ask you a question are you from the UK or US
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Asking about the code's reasoning. And Megawatt- I fully get you!

If you are looking for reasons why the code wants this or that is something every body wants. You have hundreds of people who make up rules and regulations in the BIS 7671 and they all have different opinions

 

[Cookie]

I'm from the US- but want to learn about both.

 

[Dan]

Staff have cleared up some posts in this thread. Please keep threads on topic and don't respond to rubbish, just report it, it saves us time. Cheers.

 

[Megawatt]

I'm from the US- but want to learn about both.

So we got something in common good luck
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Staff have cleared up some posts in this thread. Please keep threads on topic and don't respond to rubbish, just report it, it saves us time. Cheers.

Sorry Dan and have a great day

 

[Cookie]

We do Megawatt. Thanks