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Bukko

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Bukko last won the day on July 18 2019

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  1. Hi Paul, When I was living in the UK, contents insurance was straightforward.. until I housed stuff in a dome. They were happy for me to lug everything in and out each night but would only consider the dome as a shed and cover only a few hundred pounds. Trying to argue the dome resulted in a reduction to the risk they carried got me a blank response. Here in France, I needed to change my house insurance company to find someone through an agent, who would insure me at all. I have reasonable cover for the observatory, very limited for theft, but pretty much everything else. The catch is my buildings and contents insurance is about a thousand pounds per year... I think you are probably doing pretty well in comparison... Gordon
  2. Hi @Bivanus, in my previous life, I worked in the chemical industry. A long time ago, a lightning strike on a tall distillation tower was met with a high impedence grounding. The resulting voltage spike did huge amounts of damage to the instrumentation and process control computers and shut us down for a week. Afterwards, there was a project to upgrade the grounding system. According to lightningmaps.org, the strike was further south than the picture shows - perhaps up to 100m away and it took out many of the house breakers, as well as the Observatory supply. I understand the rationale about managing the strikees, but I would prefer to find a way to prevent one even close to my stuff. For now, I have simply driven the rods into the ground, and as soon as I get time to run the interconneccting cable, I will do resistance check to see if I am good. The ground is so wet, I am sure it is fine, so I will test again in the summer, to be sure. If I need to do something more sophissticated, I will sink something close by. I am adding enough in the wires to allow for this. Hopefully, when I am finished, I will not suffer another hit. Gordon.
  3. Thanks for the sympathy. Clay is terrible. When dry, it is like working in concrete. When wet, as you say, heavy and just sticks to the spade. Stainless steel spade seems to be a bit better, though. And there is a spade, American, I think, called a "Root Slayer". It is teflon coated and a lot easier to get the clay off. It just does not pick up much soil at a time, but good to cut through the ground. I did get a petrol auger and basically, it could not get past the heavy stones. But I am lucky here, I am surrounded by farmers and to have access to mini diggers and someone to operate it. Usual price for assistance is a nice bottle of Scotch.. Gordon.
  4. Hi, William, happy New Year ! Thanks for the link, for now, I am done but it is always useful to build up a good range of suppliers. The "soil" here is heavy clay and stones. The stones range from the small to apple sized pieces and digging is next to impossible. My SDS Plus drills were almost useless. My heaviest sledge is 4kg and it is really difficult to control it, hence, the use of a bigger SDS tool. The MAX did the job, but effectively each two length rod destroyed the coupler I used inside the SDS MAX throat. If the coupler between the two rods failed, the second length would bury itself really quickly, so I am pretty sure it is 2m deep now. As an aside, I changed the dessicaant on my ASI camera the other week. I know you use a modified plastic box with gloves fitted and Argon purge. I got a portable glovebag and used that. Basically, a much bigger ziplok bag with gloves fitted, it is designed as a portable fume cupboard for laboratory work in the field. I used a small 1 litre welding canister of Argon, and reduced the air content to less than 10% in one go. I estimate I used less than half the canister, so pretty cost effective. I will get back to the Imaging thread and update it when I get some time later... Gordon.
  5. A little update... I have struggled to find ground rods in France, either I am struggling to find them in the DIY store searches, or they are not generally available to end users. Anyway, on my last UK trip, I bought several of them and as I can't really transport stuff much longer than 1m, I got a few joiners and termination pieces. The ground, right now, is really wet so the clay and stones will give a bit. I have a couple of SDS Plus tools, but neither made much progress. I also have a more subsstantial SDS MAX concrete breaker and trying to get the rods to 2m depth teek some effort (from the breaker!!) So, I have a loose planting of a few rods that I will connect up and replace the existing house earthing cable to a local one. And when it arrives, I will fit the lightning protector and hopefully, everything will be safer. Thanks to all for the help ! Gordon
  6. Thanks, Keith. Two acres takes a whole lot of grass cutting and the pool is a great big pit that I keep throwing money into !! Anyway, I do have some sockets so can join rods to rods for the depth. The power to the domes are distributed from the warm room, so (local) earth will go with the power and I am surprised how cheap the surge protectors are. Would you be happy with the cheapies, or should I look for a more reputable manufacturer? ABB / Siemens perhaps?? G.
  7. Hi David, Keith and Mandy. Thanks for the extra input. Attached is an overhead of the house and observatory. Buildings, all three are on concrete with a vapour barrier. Warm room is wooden. The domes are elevated fibreglass on a brick "wall" 0.5m and 0.8m high. Internal metal piers are on their own concrete footings. To help with the scale, the corner of the house to the nearest corner of the warm room is just under 20m. Orientation, North is to the top. The trees to the north of the Obby are 15m+ high, many of the others vary from 5m to 15+, so plenty of conductors. As I said, I am located on relatively high ground. I thought I would have more protection from the UPS's. A decent surge protector sounds like a good idea for the whole house. I am looking into fitting some solar panels sometime soon, to reduce my electricity bill. (Electric heating...) So adding one when the supplies are merged would be easy. I did actually consider powering the Obby with a couple of solar panels and battery backup; maybe if I did this, I would not have had the failure. Hohum. David, our supplies are low voltage on little pylons. It is all being upgraded with an new external earth at the top, so hopefully this will help as well although still overhead. To balance that, we are soon to get 2GB fibre connections direct to the house, so not completely prehistoric. Keith, on your explaination of the trees, yes, they are much closer than 50m. I cannot see evidence of lightning strikes on them, but history does not guarantee the future. And yes, I expect it would be a local strike, rather than a direct one. After the incident, I found my insurance did not cover the domes, etc. so my loss. My new insurance covers it completely so any direct strike means an oppertunity to upgrade. However, I don't want that to happen. If I can summarise the proposals, I go with disconnecting the house earth and connect up a new local earth from (I think 8 ground rods) inside the warm room distribution box. By disconnecting the house earth, the UPS earths will now reference th elocal earth, so no need to take them apart. I should also fit a high capactity surge protecctor in the warm room and when I fit the PV panels, fit a 3-phase one there too. Does this all sound like a reasonable plan? Gordon.
  8. Hi Mandy, Thanks for replying and the suggestion. Tying in an isolation Tx would be quite a simple thing to do, as I just re-locate the existing L/N wires and run a new length from the MCB to the transformer. However, I have a series of UPS's in the system now, so effectively they should do the job of an isolation transformer? I am also prone to frequent, short power outages and brownouts, so the UPS's are important to protect the systems from that too. I am pretty sure my failure had something to do with a differential ground potential between the house and Obby. Everything is permanently connected and so maybe a little more vulnerable. When the strike happened, nothing in the house failed... Do you think I would still need an isolation Tx, even when using a UPS? Gordon.
  9. Hi, Bubbles. Any help/ideas gratefully accepted. The incoming supply is sealed, so I cannot tell exactly what is inside without breaking in. However, at the MCB's, all the earths are connected and run into the ground (3 phase + N come in from the top and no sign of a primary earth cable from the inncoming supply.) I am assuming the ground spike is buried there, rather than being derived from the incoming supply. Lightning protection seems to be a somewhat closed subject, with little advice available, apart from having a specialist visit to carry out a survey. I live in rural France, so not so easy. I understand what you are saying about the house earthing arrangement, I do not intend to touch any of it and simply terminate the earth wire at the warm room seperately with an attached lable explaining it. A "ring" of local ground spikes would then be terminated locally instead . My primary fault protection is frrom the RCCD, rather than relying on an earth. I also take what you say about it being a lot of work for little gain, but the last strike took out a two grand camera and a PC, so history does say it is worth some effort. The tall trees (15m+) are probably good lightning conductors so increasing my chances of a very local hit... My gut feel is the earthing change would eliminate the ground potential difference in the event of a local strike, so I guess I am looking for someone to shout at me NOT to do it !! Gordon.
  10. I am lucky enough to have built a permanent observatory in the garden. It is maybe 25m from the house but the mains cable is more like 50m long. The cable is buried and the supply distributes to the scopes from the warm room. Separate MCB's are installed, as well as an RCCD. The Obby earth is derived from the house ground, so about 50m away. A couple of years ago, I had a close lightning strike, perhaps 200m away. Following that, one of the PC's failed, along with one of the CCD cameras. Everything also goes through UPS's as well. Anyway, I have been looking that a possible solution would be to install a local ground system and disconnect the earth from the house. I have half a dozen, metre long ground spikes and my plan is to bury them around the immediate area. Interconnect with copper wire and then connect into the mains, replacing the existing ground. I am concerned that improving the local ground connection might attract a strike. I live on the top of a lazy hill and around twenty tall trees in the vicinity. Is there anyone out there who can advise if I am possibly going to make it worse? Many thanks, Gordon.
  11. Following this thread with interest... My 294MM has the same issue and cannot run it below 0c. I have purchased new dessicant tablets and plan to change over in October. I am surprised that someone in the factory would think it OK to touch the chip surface and the QC team should be working hard to stop this from happening. So I now also need to clean the chip as well.. Anyway, my plan to open the camera includes using a glove bag - a large sealable bag with built in gloves. This is in an attempt to prevent unwanted dust getting inside. Also plan to use an argon purge so the dewpoint inside the bag should be lower than -50c, so at least I can start the new dessicant with a dry chamber. If there is any interest, I will post the work here. Gordon.
  12. No swirly gradients. Perhaps the difference between the "C" and "M" versions? I also always run it with the 2x2 binning so perhaps that helps to. I have a library of bias and darks for each temperature setpoint I run. (0c is the warmest) PI does an excellent job of processing a mass of subs and makes everything look pretty good. The nearest I get to your concern would be when pushing hard to bring out the signal, there is some residual gradient, but this is possibly linked to not running enough flats. But PI does not always fully process out the amp glow and when pushing my luck, it can sometimes be seen. Example would be the S2 content on the Bubble nebula. Apart from that and the annoyance of ZWO's software not playing with non-ZWO hardware, I have been pretty happy with the camera.
  13. I use the 294MM pro cooled version. Most of the time, the amp glow is fully corrected using dark frames, never found the need to go over 500s subs, so can't comment on really long exposures. Been imaging the bubble in NB and with 500s subs and 0c due to high ambient temps, the amp glow is difficult to fully remove using only PI tools. I cannot answer for the coour version, but guess the amp glow might be harder to process out under these conditions. I use a good corrector and even then, I am prone to some elongation at the corners, so with this camera, a decent corrector is a must. Hope this helps and good luck with your choice. Gordon.
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