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Bukko

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Posts posted by Bukko

  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. 3 hours ago, Bivanus said:

    Hello @Bukko , in another life it just happened to have had to install a lightning arrester solution for some crude oil tanks placed in an area with a similar bad soil. What the designer did was to use a double approach: passive and active.

    Passive: Similar to what you say , buried electrodes with activated zinc however placed in holes that were packed with some graphite & a salt combo to improve the overall impedance, linked by metallic strips also buried from which metallic rope went to a number of  pointy lighting arresters ( one per building ) By measurement we have had them at 0.5 - 0.8 Ohm , that is below the legal requirement of 1 Ohm. 

    Active: A number of active lightning arresters place WAAAY OUT of the reservoir location. These were the spiky sphere type , Prevectron I seem to remember were called. This were the ones that "attracted" the lighting , that's why they were placed outside the perimeter. The only time I've actually saw a lightning strike was on this devices , not on the  passive ones. This type of devices have a calculated covered area that is quite large  but care must be taken to ensure a good draining path for the lighting voltage. 

    Edit: I've looked at the picture , if the structure on the left is the observatory , one active lightning arrester placed between them , around the point where there is a little bush in the picture , could protect both , but some calculations have to be done to determine the pole height. Usually the companies selling the devices also have an engineer doing this or know another company who does. 

    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.

    • Like 1
  3. 7 hours ago, Carbon Brush said:

    With clay digging you have my sympathy🤣.
    When digging my garden pond I soon discovered spades and picks just stuck in th clay and it took minutes to extract them!
    The solution was a petrol driven post hole borer with 150mm auger - then take away the loose spirals using shovels.

    If you drill the holes larger than the rod diameter, the rods will drop straight in.
    Given a little time, the clay will move to grip the rods tightly.

    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.

    • Like 1
  4. 7 hours ago, Oddsocks said:

    Hi Gordon.

    Sounds as though you are sorted now but if you need extra rods, couplers, tapes (or other electrical parts) etc then try this French supplier:

    https://www.123elec.com/gamme-materiel-electrique/mise-a-la-terre.html
     

    You can search the web using the term “Piquet de terre cuivré” (Copper earth stake) which should find other France based suppliers.

    Never thought of using a SDS hammer drill to push the rods in myself, being rather old school I used a 14lb sledge and a steel bolt screwed into the rod coupler threads as a load spreader.
    The terrain at my UK observatory was stoney river delta and it took a good hour of swinging the sledge to drive 2m rods into the ground in 1m sections, with frequent pauses to re-tighten the coupling between the first and second rod sections as they tend to unscrew themselves under the shock of being hammered into the ground.

    William.

    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. 6 minutes ago, AstroKeith said:

    Looking at your photo (nice place BTW!) I think it would just fail the 50m sphere test, so there is a chance of a direct hit but sounds like you are insured for that.

    Induced currents are the problem as they will be produced by nearby strikes and even cloud to cloud discharges. The Surge protector in the warm room, plus a good local earth should stop such currents. You have a small distance between warm room and observatories but to be safer, make sure your observatory earths run back along the same path at the supply, back to the warm room earth.

    8 earth rods arent needed - rather one deep one. 2.4m is usually called for.

    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.

    grounds.jpg

  8. 5 minutes ago, Mandy D said:

    You might want to consider an isolation transformer to do this. You then do not run into the problems highlighted by @Bubbles82. Run a two core cable from the secondary of the isolation transformer to the observatory and make the earth connection at the observatory end, tying down one side of the secondary to it. This, then becomes your neutral.

    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. 2 hours ago, Bubbles82 said:

    Hope can offer a little help,As an electrician I’d suggest that is going to be less than ideal and alot of effort for no real gain. Simply I would agree you could TT the cu in the observatory to give you a shorter fault path. The regs around this are strange when read up about and would suggest you have a look before making any changes that could affect you earthing arrangement back at the house .

    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. On 07/09/2023 at 10:18, Elp said:

    Do you experience strange swirly gradient patterns across the image (not a linear LP glow one)? It's to do with the bias signal causing flats to not subtract from the lights correctly.

    My 294MC uncooled doesn't necessarily have an issue with amp glow, it's the random colour pattern it generates due to the above and am wondering how the mono version is affected by it.

    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.

  14. On 01/04/2023 at 21:13, McComiskey said:

    Bukko, how did you install the fan in the scope dome?

     

    Sorry, just picked this up...

    The Scopedomes are mounted on top of a couple of rounds of bricks. I use the big, largely hollow terracotta types. All I did was simply drill a hole through one of the bricks for the ducting. (I pull air through that way and allow it to flow around the base and through the shutter.)

    I included an IP rated 2-way switch on the exterior to allow me to change device without having to open the dome.

    I have the dehumidifier set slightly as "wet" as I can and even though I get a LOT of moisture sometimes, I have not needed to use the dew heater tape around the scope. But I do spend as little time as possible inside the dome, as humans tend to kick out a lot of moisture when breathing.

    I guess you should be able to drill the wall of the Pulsar, especially if you have some of those bay panels...

     

    Hope it helps.

    Gordon.

  15. I seriously considered fibre runs for my installation a few years ago - Maybe I looked in the wrong place, but found the costs pretty expensive. I do have around a 50m run from the house to the observatory, plus local runs of around 10 and 15m. I was concerned that any patch fibres I purchased might be too short, so estimating plus 20% seemed like a good idea.

    In the end, I opted for Cat5e and have no ptoblem running at a full gigabit per second. With SSD's on each PC, transfer rates are sustained at 100MB/s.

    For redundancy, I installed two cables per run, in case a mouse eats one, but so far, so good. The main run from the house is in a trench and for about 15m, the power is shared with the Cat5e cables. The different cables are in separate conduits, about 20cm apart and any small amount of induced voltages in the Cat5e is unlikely (And in practice, I have had no issue).

    I have suffered a lightning strike close by the house. None of the network components failed, but I did lose a PC and camera. I also think I suffered some electronics damage to a mount and have noticed some degradation in functions since. I use several UPS units to offer some protection and working on installing some ground rods and hoping this will help prevent another incident. But a thought in my mind is telling me I might end up offering a better ground than the surround and end up attracting another strike...

    But back to the fibre optic thread, if I was doing it again, I would work harder on specifying fibres, I think.

     

    Gordon.

  16. In the early part of this thread, it is mentioned that newcomers to AP sometimes have limited budgets and no sound idea what they would like to concentrate on...

    And we need to think "out of the box" to come up with ideas and possible solutions.

    I am interested in where the forum is with regards proposing the use of a remote imaging site instead of purchasing hardware?

    Different scopes, good cameras and mounts and with a budget of a few hundred pounds, could probably get quite a lot of quality imaging runs for the money -  good value for money, compared to how few clear nights we often get in a year..

    Gordon.

     

     

  17. Thanks, Andy,

    Glad to hear you have a resolution.

    I did contact the supplier, yes, it is still under warranty.

    I have tried everything asked of me, but it still does not work. Lots of things have kept me busy, but I really should get back in touch and resolve this.

    I do not use the i-Polar, as I prefer to drift align, but I suppose that is not the point.

    Take care,

    Gordon.

  18. On 21/12/2021 at 12:53, ABPhotosUK said:

    My CEM70 has developed a fault with the USB socket on the main panel which is preventing me connecting to the mount from my PC. I'm waiting on a new bridge board from iOptron but wondered if anyone has a workaround for this in the meantime. I've tried an FTDI cable connected to the handset but it appears this doesn't work (other than for handset firmware upgrades). Any help would be much appreciated.

    CS,

    Andy

    Hi Andy,

    I also have an issue with the USB connection to my CEM70.

    I currently only use it with the handset, but the i-Polar connection does not work anymore. I am guessing it is the same issue you have found so my fix is likely to be the same.

    Have you managed to get a replacement board yet and does it all work now?

    Thanks,

    Gordon.

  19. Hello Vlaiv,

    I was sorry to read the tale of your pier problem. I was trying to understand what went wrong and remember back when I did mine. You say you could break off pieces of concrete in your hand.. The only thought I had was lots or air trapped in the mix.

    When I poured the pier bases, I used an industrial vibrating poker to get rid of trapped air in the mix. I was surprised at how much in compacted. I can only assume your builders did not do this and so you have problems. A well poured concrete pier should work for you..

    Good luck.

    Gordon.

    • Like 1
  20. I use the same dehumidifier in my 3m Scopedome - probably about the same internal volume as the 2.7 Pulsar... I have run an external drain line from the dehumidifier to a 10 litre bottle outside the dome and leave it running 24/7.

    On a clear night, I will switch over to a ventilation fan that pushes fresh air through the dome a couple of hours before sunset, rather than have the heat output from the dehumidifier passing through the dome.. Seems to work for me.

    Gordon.

  21. On 26/10/2021 at 23:53, Kimboman said:

    hi great project and very entertaining would like to see it finished

    Thanks !

    TBH it has not changed much since my last posted pictures. The warm room roof is replaced with a flat sloping version and I finished throwing gravel around the area. Oh, also bedded some paving slabs for a couple of tripod mounted scopes and a group of 4 slabs for a Dob. AND installed external power sockets for the scopes...

    I will try and get a decent picture and post, but the weather is not so good right now..

     

    Gordon.

    • Like 1
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