On 27/12/2018 11:11, Tufnell Park wrote:
On 26/12/2018 18:01, Chris B wrote:
On 26/12/2018 17:05, Tufnell Park wrote:
On 26/12/2018 16:24, Chris B wrote:
I have just been out to walk off at least part of the excesses of
the last couple of days and came across a street lamp with its
access panel missing.Â* A photo is here.

https://www.dropbox.com/s/fj3m471n4u...4906a.jpg?dl=0

This looks like a single street lamp unit is protected by a 32A CB.

1) I would have thought the rating for a single bulb would be lower.
(what are street lamps 400W?).

2) Some have said (even on this NG), that its impractical to have a
EV charging point on street lamps as they don't have the current
carrying capacity. Now 32A might not effect a "fast charge" but
could significantly increase the battery charge if left plugged in
all day (or all night).


Any thoughts?


The CB is rated to protect the cabling to the lamp. It is unlikely to
be a 400w lamp, sodiums are usually around 80w.

OK so supplementary question, why use cable capable of 32A to run up a
pole with an 80W lamp at the top.Â* Repeated on many, many posts would
this not lead to considerable unnecessary expense, compared with
running say 5A cable?

Standardisation and future proofing are the likely reasons.

It is cheaper to have a standard installation which will cater for all
future lamp requirements without rewiring i.e a 32A cb does not cost
much more than a 5A plus the minimum size cable say 1.00 mm2 is not
greatly less cost than a 2.5 mm2. (In bulk purchase deals the cost is
probably no difference).

As I mentioned before, what you see there is a switch not a circuit
breaker.

Very similar to this unit:

https://www.lucyzodion.com/products-...midi-isolator/

There is provision in the box to add circuit breakers or fuse carriers
beside the switch. The yellow plastic bit is designed to interlock them
such that you can't access the devices with the power on.


--
Cheers,

John.

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