Amendment 2 and AFDD's

[Dave Appleby]

Hi.

Been reading the but around 427.1.7.

Does anyone have any idea on retrospective application?

Is this going to apply to every board change or just adapted to new builds and then as a C3 recommendation for everything else?

Given prices it's going to be a massive cost change on a board swop. Plus, I know for certain I'm going to have space issues with anything over 30 years old here in Fife.

Thoughts?

 

[pc1966]

Perhaps we should install all power circuits with parallel conductors. For another amendment/edition, all accessories could include another live terminal for high integrity supplies.

Or return to the old Wylex board style of double screw terminals?

The Wago style of spring loaded ones were something I looked at with deep suspicion when they first came out, but it turns out they (with clean cable, etc) give a good reliable connection and no need for someone to have either proper experience and training, or to have and use a torque screwdriver to get reliable connections.

 

[Dave Appleby]

And nothing protects against THIS!

Big shout out to SPN who were brilliant yesterday. Onsite in under 90 minutes. Fixed in 30 more.

 

[stevethesparks]

Or return to the old Wylex board style of double screw terminals?

I'm a big supporter of that, particularly on the main switch terminals.

 

[newfutile]

the new Wylex boards have double screw terminals on them , which was a pleasant surprise

 

[brianmoooore]

And nothing protects against THIS!

Big shout out to SPN who were brilliant yesterday. Onsite in under 90 minutes. Fixed in 30 more.

Wouldn't any downstream AFDD that was loaded detect this and switch off. The current passing through the AFDD will be varying with an arc's signature whether the arc is before or after it.
If all loads were AFDD protected, the current through the cut out would fall to zero and the resistive heating would stop.

 

[pc1966]

Wouldn't any downstream AFDD that was loaded detect this and switch off. The current passing through the AFDD will be varying with an arc's signature whether the arc is before or after it.

That assumes it was arcing, and not just a few tens of mOhm resistance heating.

 

[LastManOnline]

That assumes it was arcing, and not just a few tens of mOhm resistance heating.

Yes. And not even a few tens of ohms is required. A half ohm (poorly tightened main fuse) will produce 30 Watts of heat in a fuse enclosure under full load. . Added to the heat produced by the fuse under normal working circumstances.

 

[pc1966]

Yes. And not even a few tens of ohms is required. A half ohm (poorly tightened main fuse) will produce 30 Watts of heat in a fuse enclosure under full load. . Added to the heat produced by the fuse under normal working circumstances.

I was talking of milli-ohms.

Say 50A (shower and/or cooker) & 0.05 ohm = 125W

 

[LastManOnline]

I was talking of milli-ohms.

Say 50A (shower and/or cooker) & 0.05 ohm = 125W

My error. Never saw the little "m". Next stop.. specsavers