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PostPosted: Fri Dec 11, 2015 7:47 pm 
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I think if nodes lose signal they day burn.

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PostPosted: Wed Dec 16, 2015 8:54 pm 
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the dark lord wrote:
A quick query....

Can anyone advise what would happen if a lamppost with a collector was taken out by a collision....

A) At Night
B) During the day

i.e. what would happen to the lamps under the control of the Collector

I'm particularly interested in relation to the Mayflower/Harvard System

The Harvard system uses Branches as opposed to Collectors on the Zodion system. (same thing different name!!)
If a branch is removed due to an accident or loses its supply, then directly there is no effect on the nodes linked with that branch. These nodes will continue to operate daily, but over the weeks their switching profiles will become more and more out of time as the dusk/dawn times alter. Each node receives a regular update from a calendar telling it when to switch. The nodes will also dayburn if they lose supply at any point.
Once the existing branch is re-energised the nodes will re-sync and return to correct operation. Should the branch be replaced in its entirity, then the nodes will have to be manually transferred on the computer to the new branch.


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PostPosted: Wed Aug 03, 2016 4:17 pm 
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Over the last couple of years, Hampshire motorway lighting has been converted from group switched ZX3/4 lanterns to (mostly) Lumas retrofitted to the existing columns with RF switching. At least 3 different node systems seem to be in use with the feeder pillars modified to make the supply to the columns permanently on.

However its not been a very reliable system. At the bottom of the M3, there have been numerous sections with a large number of day burning lanterns.

The M27 has probably dozens of day burners - its not clear if these are the same each day or if its more random!

A different failure mechanism was observed on the M275 today which is actually maintained by Portsmouth City Council rather than Highways England, although the same lanterns and RF switching is employed.

On a section of central reservation lighting with twin bracket Lumas, the lanterns on the western side brackets were all on, whilst the lanterns on the other side of the brackets were off.

This just highlights the flexibility of RF switching, but is it really needed? Is there really the need to map lighting per carriageway rather than between mileposts on both carriageways?

Given the cost of individual nodes (there are hundreds, possibly into a thousand), the need for software, GSM charges for basestation to master node communication, and the labour to manually map cells to software and monitor the system, is this really a worthwhile investment?

Dimming isn't utilised, part night isn't used anymore, and the software isn't being used to flag faults for repair. So what advantage does RF switching actually achieve in this case? The old mechanism of group switching by feeder pillar and perhaps 25 conventional NEMAs (spread across the feeders) achieved a far more reliable system, at far lower cost.


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PostPosted: Sun Aug 14, 2016 12:09 pm 
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An interesting point - I suppose the only real advantage on the motorways is to reduce large-scale failures if feeder/cell went down.

When Sheffield began it's PFI, it announced it would be using the Telensa radio controlled system so they could dim the lights down at night, and provide remote-monitoring of failed units. The only problem with this is that all of the lights have been fitted with NEMA nodes which don't actually support dimming at all unless the lanterns are fitted with a special module inside (which I doubt has happened).

Dimming could be really beneficial on the motorways, considering how many high-power lanterns are in operation. However, there are PECUs which have integrated dimming capabilities which work on essentially the same principle as part-night switching and I imagine they're somewhat cheaper than radio.

Seems that the real problem with radio nodes is the implementation by the local/highway authorities, rather than the systems themselves.


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PostPosted: Tue Oct 11, 2016 6:39 pm 
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Wiltshire has been using the Telensa RF node switching for the last couple of years and employs selective part night operation in some regions. However my village is too rural to be within reliable range of the base station in Salisbury, so conventional photocells are employed, as a result I haven't been able to witness the switch on regime for the Telensa system.

However a trip into Salisbury this evening coincided with switch on. I had assumed the columns would be switched on either by large zones (like the Mayflower system in Hampshire) or at least on a street by street basis.

However, the switch on is staggered not only by street, but within each street. Salisbury still retains SOX, and in these locations, it is clear to see that each lantern has switched on at a different time as they were all at different stages of warm up. This is repeated on SON lit streets, it was rare to see consecutive lanterns lit, it was all random.

Some element of zone control is also in use as in some areas, SOX was only just turning on, where as in others, it had clearly switched earlier.

It may be possible that I witnessed the all night or perhaps the part night lanterns being switched in individual groups, which may explain the non uniform pattern. However I wonder if each node has a random timer function built into it, so that actual switch on is random after triggering?

Such a function would prevent power surges, especially since Wiltshire retains legacy lanterns with magnetic gear and hence high in rush currents.

The South Coast PFI utilises electronic gear lanterns which are inherently "soft start", so switching large groups of lanterns at once is unlikely to cause supply side surges.

I wonder how the switch on is implemented in Essex which also uses the Telensa system? Perhaps David can enlighten us.. ;)


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PostPosted: Wed Aug 15, 2018 5:56 pm 
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There is a new version of the Telensa node, rather than than familiar "pointed hat" shape, they now look like a double height NEMA cell but with a rounded top.

This new version includes a GPS receiver,  so the node can report back its actual column position. Previously a barcode on the node giving its serial number was manually matched to the column by human input on the CMS software. The incorporation of GPS means the CMS is updated entirely automatically.

The GPS nodes are also 5 wire types to allow dimming via the DALI system. As Wiltshire largely has magnetic gear in legacy lanterns, the original nodes were 3 wire non dimming types.

The increased technology comes at a price though - around £100 for one of the new nodes. They are replacing the older nodes in lanterns which are DALI equipped -all Lumas/V Maxes that have been fitted in Wiltshire. The older nodes however are being reused elsewhere.


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PostPosted: Sun Aug 26, 2018 2:39 pm 
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Hi All,

I have just  been looking at the Zaga specifications which come in a series of book publications. It looks like they are attempting to set up a standard for how control systems interface to the led light drivers. It looks like it is using DALI protocol as the base then building on that. Here is the link to the books http://www.zhagastandard.org/books

Regards Andrew.


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