UK Are surge protection devices fitted before or after the main switch

[L1Jay1]

Are surge protection devices fitted before or after the main switch

 

[Taylortwocities]

Have a think about what the main switch does, and what it is for.
if you don’t know the answer, then maybe someone competent should be doing the work.

 

[Phil L]

Hi L1Jay1 where do you think it should be installed?

 

[Megawatt]

Hi L1Jay1 where do you think it should be installed?

What about putting it in the closet ?

 

[Strima]

What do the manufacturers instructions say?

 

[SparkyChick]

Clearly 'tis the season to be grumpy!

How about you guys take a look at his profile and maybe go a little easier on him... it clearly states he's a trainee... just because someone doesn't have the trainee tag, doesn't mean they aren't.

@L1Jay1 , maybe consider signing up for the trainee section of the forums. You'll get a trainee tag so everyone can see you're training and you'll get access to a trainee only area which only trainees, staff and mentors can access so you can ask questions such as this without getting this kind of response.

To answer your question, they would generally be installed after the main switch. The ones in most domestic boards are installed as close to the main switch as possible, many are supplied via a circuit breaker (I've seen 32A for all the ones I've seen) but some, Hager I think, are connected straight to the main switch itself. But as @Strima says... what do the manufacturers instructions say?

 

[L1Jay1]

Have a think about what the main switch does, and what it is for.
if you don’t know the answer, then maybe someone competent should be doing the work.

I’m simply asking the question
[automerge]1577085576[/automerge]

Clearly 'tis the season to be grumpy!

How about you guys take a look at his profile and maybe go a little easier on him... it clearly states he's a trainee... just because someone doesn't have the trainee tag, doesn't mean they aren't.

@L1Jay1 , maybe consider signing up for the trainee section of the forums. You'll get a trainee tag so everyone can see you're training and you'll get access to a trainee only area which only trainees, staff and mentors can access so you can ask questions such as this without getting this kind of response.

To answer your question, they would generally be installed after the main switch. The ones in most domestic boards are installed as close to the main switch as possible, many are supplied via a circuit breaker (I've seen 32A for all the ones I've seen) but some, Hager I think, are connected straight to the main switch itself. But as @Strima says... what do the manufacturers instructions say?

In the live boards the spd is before the main switch
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What about putting it in the closet ?

What about putting you in the closet

 

[Wilko]

In the live boards the spd is before the main switch

Hi - normally the main switch isolates all the equipment in the board, is that what you mean?

 

[Ian1981]

The spd normally sits in parallel with the installation.
It should be capable of being isolated for maintenance purposes.

 

[L1Jay1]

Hi - normally the main switch isolates all the equipment in the board, is that what you mean?

Sorry I meant a LVE board , I’ve seen a LVE board with surge protection already installed in it , the SPD is before the main switch in this board , this got me confused.
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Clearly 'tis the season to be grumpy!

How about you guys take a look at his profile and maybe go a little easier on him... it clearly states he's a trainee... just because someone doesn't have the trainee tag, doesn't mean they aren't.

@L1Jay1 , maybe consider signing up for the trainee section of the forums. You'll get a trainee tag so everyone can see you're training and you'll get access to a trainee only area which only trainees, staff and mentors can access so you can ask questions such as this without getting this kind of response.

To answer your question, they would generally be installed after the main switch. The ones in most domestic boards are installed as close to the main switch as possible, many are supplied via a circuit breaker (I've seen 32A for all the ones I've seen) but some, Hager I think, are connected straight to the main switch itself. But as @Strima says... what do the manufacturers instructions say?

Sorry I meant LVE board , not live

 

[DPG]

When you say the SPD is before the main switch, do you mean physical position or actual wiring order though?

 

[Baddegg]

When you say the SPD is before the main switch, do you mean physical position or actual wiring order though?

I was trying to think of a way of wording that @DPG, stupid hangover! ?

 

[SparkyChick]

Sorry I meant a LVE board , I’ve seen a LVE board with surge protection already installed in it , the SPD is before the main switch in this board , this got me confused.

This picture illustrates @DPG 's point perfectly. Physically it appears before if you're looking from right to left, but wiring wise it's most definitely after the main switch.

 

[L1Jay1]

I was trying to think of a way of wording that @DPG, stupid hangover! ?

I was trying to think of a way of wording that @DPG, stupid hangover! ?

When you say the SPD is before the main switch, do you mean physical position or actual wiring order though?

I was trying to think of a way of wording that @DPG, stupid hangover! ?

View attachment 54815

This picture illustrates @DPG 's point perfectly. Physically it appears before if you're looking from right to left, but wiring wise it's most definitely after the main switch.

View attachment 54815

This picture illustrates @DPG 's point perfectly. Physically it appears before if you're looking from right to left, but wiring wise it's most definitely after the main switch.

View attachment 54815

This picture illustrates @DPG 's point perfectly. Physically it appears before if you're looking from right to left, but wiring wise it's most definitely after the main switch.

Clearly 'tis the season to be grumpy!

How about you guys take a look at his profile and maybe go a little easier on him... it clearly states he's a trainee... just because someone doesn't have the trainee tag, doesn't mean they aren't.

@L1Jay1 , maybe consider signing up for the trainee section of the forums. You'll get a trainee tag so everyone can see you're training and you'll get access to a trainee only area which only trainees, staff and mentors can access so you can ask questions such as this without getting this kind of response.

To answer your question, they would generally be installed after the main switch. The ones in most domestic boards are installed as close to the main switch as possible, many are supplied via a circuit breaker (I've seen 32A for all the ones I've seen) but some, Hager I think, are connected straight to the main switch itself. But as @Strima says... what do the manufacturers instructions say?

When you say the SPD is before the main switch, do you mean physical position or actual wiring order though?

When you say the SPD is before the main switch, do you mean physical position or actual wiring order though?

in LVE , SPD is before main switch

Have a think about what the main switch does, and what it is for.
if you don’t know the answer, then maybe someone competent should be doing the work.

When you say the SPD is before the main switch, do you mean physical position or actual wiring order though?

[automerge]1577093974[/automerge]

View attachment 54815

This picture illustrates @DPG 's point perfectly. Physically it appears before if you're looking from right to left, but wiring wise it's most definitely after the main switch.

In the LVE board it’s before main switch, I’m trying to understand this and the way it’s wired, it appears to be wired before the main switch aswell.

 

[Baddegg]

@L1Jay1.....just an observation.....constructive criticism even.....but I think you may need a little work on merging posts....possibly maybe?.....??
But I think @DPG and @SparkyChick has nailed it for ya here...

 

[DT1991]

Refering to your LVE board , The incomming tails would terminate into the top of the main switch, so the SPD would be after the main switch.

 

[Strima]

in LVE , SPD is before main switch View attachment 54817



[automerge]1577093974[/automerge]

In the LVE board it’s before main switch, I’m trying to understand this and the way it’s wired, it appears to be wired before the main switch aswell.View attachment 54818

In that style of board the SPD is after the main switch. The meter tails terminate into the top of the main switch.

Ideally on an installation all consumer equipment should be after a main switch to allow for safe isolation. But if the supply was split before the main switch then the SPD would have to be before the switch as it is designed to protect the installation and not just the board..

With a lot of manufacturers if the main installation supply fuse (DNO) is below a certain rating there's no requirement for over-current protection for the SPD.

 

[L1Jay1]

Refering to your LVE board , The incomming tails would terminate into the top of the main switch, so the SPD would be after the main switch.

Sorry I’ve looking at this in the wrong way , the SPD is after the main switch and is pre wired , no need for over current protection , think I’ve got that now
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In that style of board the SPD is after the main switch. The meter tails terminate into the top of the main switch.

Ideally on an installation all consumer equipment should be after a main switch to allow for safe isolation. But if the supply was split before the main switch then the SPD would have to be before the switch as it is designed to protect the installation and not just the board..

With a lot of manufacturers if the main installation supply fuse (DNO) is below a certain rating there's no requirement for over-current protection for the SPD.

When SPD is after main switch and is pre wired , then the is no current flowing through it , am I correct .

 

[SparkyChick]

Sorry I’ve looking at this in the wrong way , the SPD is after the main switch and is pre wired , no need for over current protection , think I’ve got that now
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When SPD is after main switch and is pre wired , then the is no current flowing through it , am I correct .

Whether it needs over current protection is down to the manufacturer.

SPDs are typically metal oxide varistors... At mains voltage these are high resistance and consequently pass no to little current. As the voltage increases, there resistance drops and they conduct more current, dumping the spikes to earth. They may also has discharge arrestors (I think that's what they are called).

The same technology is present in surge arresting extensions which can cause low insulation resistance readings (tip... If an IR test is poor at 500v, if it's good at 250v, it's possibly a surge arrester in circuit).

 

[westward10]

In normal circumstances there is no current flowing through them. They only become active if transient voltages occur diverting them to earth before it can cause possible damage to equipment. In your pic an earth is required from the device to the consumer unit earth terminal.