22-05-2017, 07:16 AM
(This post was last modified: 22-05-2017, 07:18 AM by ppppenguin.)
Have you booked your ticket(s) for the VIntage Wireless Museum Garden Party? It's on Saturday June 3rd.
It's always a great success even though Gerry is no longer with us.
There are major works in progress. If you've been fairly recently you'll know that the upper floors of the house are no longer part of the Museum and that more of the shed space has been converted to display areas. The latest developments are that the 2 storey shed has been completely re-organised. The stores on the ground floor have been moved upstairs while the vacated space is now for display. Mind your head if you're over about 5'9"
3 of the old sheds were in very poor condition and are being demolished. The valve lab and old transmitter shed have already gone while the stores/transformer shed will be going very soon. The plan is to put a new large shed on this site, including most of the quadrangle.
I was at the Museum yesterday afternoon. I was assisting Lucien in ensuring that the electrical feeds to the old sheds were made safe. The shed electrics are rather complex, designed by Lucien and Gerry about 30 years ago but never fully implemented. It took a certain amount of head scratching to isolate everything that should be removed while leaving everything else intact and working. There's more electrical work to be done but at least the shed demolition and building can proceed safely.
While doing the work we found that most of the sockets in the sheds failed an earth loop impedance test rather badly. In the region of 70R when it should be less than 1R in most cases. Again took some head scratching to track down the fault. Most of the wiring is in steel trunking and conduit, with the steel being used as the earth conductor. This was common practice 30 years ago but was outlawed by later editions of the wiring regulations. It's now mandatory to have a separate earth conductor in conduit and trunking. There's no requirement to retrofit older installations but they must still be kept safe. Lucien found that 2 critical bits of trunking hadn't been properly bolted to an enclosure that contained contactors etc. A few bolts and some wire soon sorted that out. It must have passed the tests when it was installed but somehow this problem had developed. We don't know how or when and we don't much care; it's now fixed. The sockets we checked had less than 0.5R earth loop impedance after the fix.
It's always a great success even though Gerry is no longer with us.
There are major works in progress. If you've been fairly recently you'll know that the upper floors of the house are no longer part of the Museum and that more of the shed space has been converted to display areas. The latest developments are that the 2 storey shed has been completely re-organised. The stores on the ground floor have been moved upstairs while the vacated space is now for display. Mind your head if you're over about 5'9"
3 of the old sheds were in very poor condition and are being demolished. The valve lab and old transmitter shed have already gone while the stores/transformer shed will be going very soon. The plan is to put a new large shed on this site, including most of the quadrangle.
I was at the Museum yesterday afternoon. I was assisting Lucien in ensuring that the electrical feeds to the old sheds were made safe. The shed electrics are rather complex, designed by Lucien and Gerry about 30 years ago but never fully implemented. It took a certain amount of head scratching to isolate everything that should be removed while leaving everything else intact and working. There's more electrical work to be done but at least the shed demolition and building can proceed safely.
While doing the work we found that most of the sockets in the sheds failed an earth loop impedance test rather badly. In the region of 70R when it should be less than 1R in most cases. Again took some head scratching to track down the fault. Most of the wiring is in steel trunking and conduit, with the steel being used as the earth conductor. This was common practice 30 years ago but was outlawed by later editions of the wiring regulations. It's now mandatory to have a separate earth conductor in conduit and trunking. There's no requirement to retrofit older installations but they must still be kept safe. Lucien found that 2 critical bits of trunking hadn't been properly bolted to an enclosure that contained contactors etc. A few bolts and some wire soon sorted that out. It must have passed the tests when it was installed but somehow this problem had developed. We don't know how or when and we don't much care; it's now fixed. The sockets we checked had less than 0.5R earth loop impedance after the fix.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
