Ledbury Portal Community Forum

Sunday 16th August power cut at ten past two this afternoon for about 15 minutes (see clock tower) - Phoned Central Networks - their # has changed to 0800 329 1111 - and they told me they had no record of it, so it couldn't have happened. They told me if the power was out for more than 30 seconds they would have to send engineers out - which they didn't do.
So that's clear.
Also a week or two ago we had a late night power failure (my independent power supply informed me), but I guess that didn't happen either!

About 20:35 yesterday (18th Feb 2010) most (all?) of Ledbury lost electricity in a power cut that lasted about 2 minutes.
According to Central Networks there was a fault in HR1 so a process of 'switching' took place to regain power in HR1. This resulted in a 'ripple effect' causing power cuts here and elsewhere.

John, I hope to try and shed some light on your recent issues with power reliabilty. I have worked in the electricity industry for many years and now currently work as a college lecturer.

You have said you have interruptions lasting 1 minute or central networks have mentioned birds or trees may have caused these short interruptions. As you live in hereford there are a lot of overhead lines in this area carrying 11kv (11 thousand volts). Due to these lines being near trees the overhead system has a piece of equipment installed on the circuit called an auto-recloser. What an auto-recloser does is to break the circuit under fault conditons, i.e if a tree branch falls on the line this will break the circuit and the recloser will then give this a few seconds to clear before closing and remaking the circuit/ If the tree hasnt cleared it will continue to break and close until it has cleared or it may be set to break and close a number of times before it will stay broken and engineers would be sent to investigate further.

You also referred to the switching process. Switching is a way to restore supplies on a high voltage fault. On the networks whether it be on underground cables or overhead lines there are pieces of equipment called switchgear. What switchgear does is enable engineers to work on a certain part of the circuit dead by switching the load to an abnormal route therefore not losing supplies to customers, however what central networks are referring to is switching to restore a fault. When a fault develops on the HV network it will trip all of that circuit. Engineers will switch at certain points on the network to isolate fault and restore supplies to customers by an abnormal source, often called backfeeding. Alternatively if a circuit has tripped due to a fault, the switching process can also have effected on other circuits, primarily due to backfeeding the circuit.

As for central networks being unaware of the cuts you have experienced, not all of the network is monitored by tele control therefore they will rely on calls from customers to advise them of loss of supply.

I hope this has been a help to you

JJ

Micro-second power cuts and surges at 1:21pm and 1:26pm today 26th October 2010.
Logged it with Central Networks - I wish other people would too, then they might do something about it.