OT(Slightly) Street Lamp Infrastructure.

[harry]

The last street lights I wired had 5a fuses and 10a rated cable.

[Richard]

Time and place might actually be of use. If in outer Mongolia 1974, it may well have been cutting edge.

[Dave Plowman (News)]

Minimum SWA size? A smaller cable wouldn't be so robust too.

[invalid]

The street lights around here are individually tapped off the feeds for the houses. The feeds are probably a few hundred amps. There is no separate lighting circuit.

[Tufnell Park]

Usually 60A feeds to street lamps in 25 mm2 concentric pvc cable jointed to the 3c & neutral 415v alpex street supply cable.

[Dave Liquorice]

Only major "strategic" routes are Highways Agency. Up here that's the M6, the A69 Carlisle towards Newcastle, the A66 across the M6 to the A595 then down to Sellafield and A590 to Barrow from the M6.

All our other roads are under the Cumbria Highways a partnership between the County Council and Amey. But that's not the whole story when it comes to lighting. There are "street lights" and "footway lights", the former are designed to light the highway, the latter the "foot way". However the classification of the "highway" has little to do with a given light being a "street light" or a "footway light". The A road running through the center of town only has "footway lights", the housing estates with no through route have "street lights"...

"Street lights" come under Cumbria Highways. "Footway lights", currently, come under the District Council but once the legal wrangling has been sorted out the footway lights are going to be devolved to the Parish Council.

I'd assume that the Highways Agency looks after the *street* lights on the M6, A69, A66 etc but wouldn't like to bet on it!

Our true street lights do, the footway lights don't, AFAIAA.

[Andrew Gabriel]

The ones along my road were recently rewired, and lanterns changed from LPS to fluorescent. Both old and new use 4mm² sheathed singles up the column to the lantern (which is well under 100W). I suspect the thick cable is used because it's unsupported for a

6m drop down the column. Not sure why singles, maybe they rattle less when the column vibrates in the wind.

BTW, street lighting is exempt from normal voltage drop limits on its supply cables. Street lighting has always handled significant drops by using tapped ballasts originally to compensate for voltage drop at the end of a long run, or nowadays switched mode PSUs.

[Andrew Gabriel]

Any installation in the last 5 or more years will be Zigbee controlled using a mesh network between the NEMA controllers (what used to be the plug-in photocells on the lanterns, but no longer are - they are mesh radio).

There are typically several hundred lamps running in a mesh with a master controller (these are physically larger versions). The master controller connects the mesh to mobile data network, and each lamp in the mesh can be monitored and controlled separately. The individual NEMA controllers also generate DALI and 0-10V dimming outputs, which can be used with dimming control gear to reduce light output. They also measure the lamp power consumption and report this back for electricity charging purposes, and to alert a failed lamp.

The master controller has a photocell and temperature monitoring, but these are to report back to central control over mobile data network. (Temperature monitoring is used to alert council if salt spreading is required.)

is the scheme used throughout all of Hampshire.

[tabbypurr]

why don't they use 1mm CCS cable going up the pole? Far cheaper surely.

NT

[Cynic]

I begged a column that was being replaced outside my gate as part of an area scheme. It had very light in ground surface corrosion and should be good for another twenty years. The supply to the lamp from the cut out ran in 3 core sheathed flex. The fused cut out was fed in concentric cable jointed straight off the street ug supply cable. Presumably the cut out is selected based on the prospective fault current.