Remote cabling question.

[Nigella Bryant]

Hi all, I've recently moved and my observatory has been dismantled waiting for all the process of rebuilding it at my new home. I'm 61 soon and although able still to do many things I'm hoping to future proof my observing in later life when perhaps cold weather, etc is not conducive to a 90 year old, lol. With this in mind what kind of cabling would I need to put in the ground for remote access. It makes sense to me to put this in while I'm doing the ground work. My Obsy is a 2.7m pulsar, my telescope is an Orion optics 12inch f4 Newtonian, currently using a neq6 mount (this may be upgraded as time goes on) I use a Canon 1000d modded camera and zwo cameras. I use my laptop for acquiring images. Hope this makes sense. 

Edited November 28, 2019 by Nigella Bryant
Content added

[pete_l]

I sincerely hope you will still be able to enjoy astronomy when you are 90 - I hope I will, too!
As for installing cabling that will last 30 years ...
I would suggest that access would be a major consideration. Over that time there will inevitably be a need to do something. Even it is just to repair rodent damage. For that reason it might be worth considering having the cabling above ground in a suitably protected and visually acceptable conduit. That would also remove any problems with the channels getting waterlogged.

To eliminate any regulatory problems with running mains voltages, you may consider a low voltage system, This would need higher currents and so thicker cables. But whatever you choose, I would suggest instaliing many more cables than you will need right now.

[Carbon Brush]

A steel wire armoured cable should be OK buried for years. It is affordable. Mains electricity will still be in use.
If you are bothered about getting it 'signed off' just have a chat with your chosen electrician.
Basically you bury the cable, pin to walls where required, etc. The electrician terminates at each end and tests.
Most electricians would rather be involved in 'clean' jobs. Not working trenches.
The only problem you might find is that some domestic electricians are out of their depth when involved in outdoor cabling or anything 'non house'.
If the electrician says it can't be done, it is worth asking for a second opinion.

Data cables are another matter. You can buy multicore data cables with steel armouring.
If you have to ask the price, you can't afford it.
Money is better spent on scope kit!

I would be tempted to use 'drainpipe technology' for data and control.
Buy readily available water pipe or drain pipe. Don't be afraid of going up on size. It will be hidden. It is all cheap and cable requirements have a habit of breeding as new devices come along.
Run a length of good quality rope through the duct. Every time you pull a cable through, run another rope.
I would start with 2 off CAT5/6 network cables and a low power (not armoured) 6/8 multicore screened- as a minimum.
It is not expensive in the grand scheme of things.

The multicore cable can be used for simple heating or dehumidifier on/off control. Use low voltage relays to isolate the mains.
It can also report intruder alarm status, etc.

Hope this helps.

David.
 

[Nigella Bryant]

Thanks David and Pete, so much to think about and regret later on when you need other cables, great suggestions.

[Nigella Bryant]

So the cat5/6 does this run to the broadband router or to the computer in the warm room/house? Would WiFi work from the scope/mount? As well as cat5/6 never installed a network so any help would be much appreciated. 

[Dr_Ju_ju]

Put a 100mm (4") drain pipe buried & MARKED, into the ground, from your proposed site to your house (at a convenient location to get inside the property)

Then run a stout nylon rope through the pipe, either on a loop, i.e. around a pulley at either end, or at least twice as long as the pipe length. This is to ensure you can get cables in from either end....

To start with, I'd run an armoured 60Amp cable and at least 2 external grade Cat5 cables, all suitably terminated & safety checked.....  That should then leave plenty of space for any future updates....

[andrew s]

You can use cat5/6 cable in many ways. You can use it from an obs computer to a network router and access your computer via remote access software over your local area network. You can run USB over it with suitable converters or even remote  mouse keyboard and screen via keyboard extenders.  I have done the first and last option but not tried USB.

I would put two cables in if I were you.

Regards Andrew 

[JamesF]

As David says, I would run at least two (so you have a spare in the event that one breaks) cat5e cables in some sort of ducting (waste water pipe is absolutely fine) from the house to the observatory in a trench.  You could run a cat6 cable, but if you really want to have a cat6 compliant network it's a pile more work and expense.  As others have said, make sure you always have a draw wire in place in case you need more later :)

At the house end I'd plug it into your router, or if you don't have enough network sockets on the router, add a small switch and plug all your wired network stuff into that and then plug the switch into the router.

At the observatory end it's probably also easiest to connect a second switch to the other end of one of the cables and the plug whatever equipment you need connected to the network into that.

If you don't want to go to that much effort, wifi to the house may work sufficiently well, but it can be a bit slow if you're transferring lots of large image files around, for instance.  I prefer wifi for convenience, hard-wired for security, speed and reliability.  If you don't want the work of putting stuff in a trench then potentially it could be run around fencing above ground, or even attached to a catenary wire run between the house and observatory, though for that you'd probably need to buy network cable with a UV-stable sheath (normal network cable sheathing will break down over time).

One issue that may require a change of plan is if the observatory electrical installation has a local earth.  If the electrician wants one because you have a steel pier connected to the ground then I'd worry about it at that point.  It might just be a case of running a fibre link instead of cat5e.

If you want power to the dome on a permanent basis then running an armoured cable in a trench would make sense.  If you're not drawing that much power and you're happy to go out and power everything up each time you want to use it then it might be a lot simpler to have an electrician install an outside socket somewhere convenient and then just power everything using an extension reel  that you plug in each time.  I think Gina and upahill both do that.

[Nigella Bryant]

Thanks everyone, much to think about over the next few months. Garden clearence first then ground work, cabling on the Obsy site. A few alternative to think about but does make sense to run two cat cables, they're cheap in the scheme of things. I'm thinking about running an armoured cable from the mains wiring in a junction box in the bungalow roof space, there's spare connectors on the ring mains. This can then be put into the trench through a pipe with the cat cable's. The mains will then run to a junction box in the dome. I'm going to build a concrete pillar as I've done before and duct wiring up that to sockets. Does all this make sense? 

[Dr_Ju_ju]

If you're going to run a spur off an existing ring main, then just check that the total possible load doesn't get too close to the MCB trip rating (should be 32A) but if possible run the cable to the main dist. board & fit another dedicated MCB\trip at a lower value 5~10A. I'd also arrange for more outlets within & even outside the dome, to cater for the unforeseen..

[Nigella Bryant]

4 minutes ago, Dr_Ju_ju said:

If you're going to run a spur off an existing ring main, then just check that the total possible load doesn't get too close to the MCB trip rating (should be 32A) but if possible run the cable to the main dist. board & fit another dedicated MCB\trip at a lower value 5~10A. I'd also arrange for more outlets within & even outside the dome, to cater for the unforeseen..

That's a better idea, thanks. 

[Carbon Brush]

Network cable should be good for a 100M run. Whether from router or a computer, or a switch.

CAT6 has the benefit of lower signal loss than CAT5, which shows on long lengths. In practice the loss restricts speed, rather than losing data.
Nowadays most network routers/switchers check the line for signal integrity and adjust their speed to suit your cable capability.

So if you have a slow router, you probably won't see the benefit of CAT6.
But if you have fast router, signals will be slow on Cat5, but fast on Cat6.
However when I say slow or fast, this only matters if you are transferring huge files between computers.
If considering connection to the internet, this is usually the slowest part of data link.

I would use Cat6 if planning for the future. New network 'boxes' generally support higher speed data transfer.

USB is best considered for linking devices that are next to each other. The cable linit is 5M unless you use a buffer/convertor of some description.
Further, a lot of USB leads do not work all that well. Buy a known name not the cheapest.

Electrical earthing is a subject often misunderstood by water, gas and electrical people. Yes you are supposed to earth water and gas pipes.

If there is a mains item on the steel pier, it should be earthed. In other words if you have a 13A socket on the pier, then the pier requires an earth bond.
If you have a goto mount, that is all low voltage kit that is isolated from the mains by the (usually) mains to 12V power supply that is often away from the pier.
In this case a safety earth is not required.

Earthing is about ensuring everything metal is at the same electrical potential.
In addition, the bond should be strong (thick) enough to withstand the prospective short circuit current until the circuit breaker (protecting the cable) trips.
In this case, taking the braid from the armoured mains cable to the pier is adequate. But if you clamp onto a single strand of the cable, it won't be.
Think of a single strand as being a piece of fuse wire. This has to remain intact until the circuit breaker in the onsumer unit trips.
Any elecrician should understand about this.

If the installation allows, ask the electrician to provide a separate circuit breaker and residual current breaker to feed the observatory only.
You don't want the house telly to go off because a mains socket in the observatory has got damp.

Sorry if this confuses more than helps.

David.

[Nigella Bryant]

52 minutes ago, Carbon Brush said:

Network cable should be good for a 100M run. Whether from router or a computer, or a switch.

CAT6 has the benefit of lower signal loss than CAT5, which shows on long lengths. In practice the loss restricts speed, rather than losing data.
Nowadays most network routers/switchers check the line for signal integrity and adjust their speed to suit your cable capability.

So if you have a slow router, you probably won't see the benefit of CAT6.
But if you have fast router, signals will be slow on Cat5, but fast on Cat6.
However when I say slow or fast, this only matters if you are transferring huge files between computers.
If considering connection to the internet, this is usually the slowest part of data link.

I would use Cat6 if planning for the future. New network 'boxes' generally support higher speed data transfer.

USB is best considered for linking devices that are next to each other. The cable linit is 5M unless you use a buffer/convertor of some description.
Further, a lot of USB leads do not work all that well. Buy a known name not the cheapest.

Electrical earthing is a subject often misunderstood by water, gas and electrical people. Yes you are supposed to earth water and gas pipes.

If there is a mains item on the steel pier, it should be earthed. In other words if you have a 13A socket on the pier, then the pier requires an earth bond.
If you have a goto mount, that is all low voltage kit that is isolated from the mains by the (usually) mains to 12V power supply that is often away from the pier.
In this case a safety earth is not required.

Earthing is about ensuring everything metal is at the same electrical potential.
In addition, the bond should be strong (thick) enough to withstand the prospective short circuit current until the circuit breaker (protecting the cable) trips.
In this case, taking the braid from the armoured mains cable to the pier is adequate. But if you clamp onto a single strand of the cable, it won't be.
Think of a single strand as being a piece of fuse wire. This has to remain intact until the circuit breaker in the onsumer unit trips.
Any elecrician should understand about this.

If the installation allows, ask the electrician to provide a separate circuit breaker and residual current breaker to feed the observatory only.
You don't want the house telly to go off because a mains socket in the observatory has got damp.

Sorry if this confuses more than helps.

David.

Thanks David, appreciate all the input. 

[JamesF]

22 minutes ago, Carbon Brush said:

CAT6 has the benefit of lower signal loss than CAT5, which shows on long lengths. In practice the loss restricts speed, rather than losing data.
Nowadays most network routers/switchers check the line for signal integrity and adjust their speed to suit your cable capability.

So if you have a slow router, you probably won't see the benefit of CAT6.
But if you have fast router, signals will be slow on Cat5, but fast on Cat6.

Need to be careful with the terminology here, because cat5 and cat5e are theoretically not the same (the standards are different), though anything sold as cat5 these days is almost certainly cat5e anyhow.  My understanding is that cat5e is good for gigabit ethernet at cable lengths up to 100m otherwise it doesn't conform to the cat5e standard (though I'm aware that some people suggest you don't try to run them that far and I'd be tempted to use fibre over that sort of distance myself).  In some situations auto-negotiating interfaces will drop down to 100Mb/s (perhaps if the cabling run is longer than 100m and thus can't support the signalling rates required for gigabit ethernet or if the cable is damaged).  If you want 10Gb/s then you do need cat6 (or cat6a for runs longer than about 50m).  I have cat5e cable runs in the house that get up to more than 40m and carry gigabit ethernet quite happily.

If that's not consistent with your understanding and you have links with more details, please do post them because it would be useful to understand how things have changed.  (I am not a cable monkey, but spent some time as an assistant cable monkey when I was involved in setting up a datacentre some years back.  I had to learn some of this stuff then, but haven't worried about it any more than is necessary for making up my own cables since.)

(My gut feeling is that it's going to be quite some time before 10Gb/s kit starts to get used in homes, but I've been wrong before   Last time I looked cat6 was about twice the price of cat5e, so if you're concerned about future-proofing perhaps it makes sense to make awkward to replace cable runs with cat6 and then use cat5e for other stuff.)

James

[discardedastro]

So - 100M, you want to do as Cat6, and 6A if you're doing this in the same duct as mains. Cat5 I wouldn't even consider at that distance - it will do 1G at 100M but only if installed perfectly - plus you'll always want a bit of slack, patch cords, etc so it's not really 100M. As posters above have alluded to, Ethernet won't get lossy (no matter how much audiophiles claim it's worth spending £100 on low-loss Ethernet patch cords) but will simply fail to negotiate higher speeds. Modern PCs will all speak gigabit Ethernet, so you really want to aim for that - it's a massive time saver vs 100M for typical large astrophotography datasets.

The only other option I'd consider would be single mode fibre - this is a tiny bit more expensive but you can get this pre-made with ends on (the hard bit) from places like fs.com, e.g. https://www.fs.com/uk/products/29606.html - this is 100% futureproof and will let you run 1 or 10G, but it has the other huge benefit that it won't interact with power cables at all, and won't introduce any grounding issues, so will be much more reliable and simplify your wiring/grounding schemes. You use a media converter on each end (something like https://www.amazon.co.uk/ipolex-Transceiver-10-1000Base-Tx-1000Base-LX-Single-Mode/dp/B078RMXPGX/ref=sr_1_6?keywords=media+converter+fibre+single+mode&qid=1574981101&sr=8-6) to turn it back into copper Ethernet, so none of your kit needs to use fibre.

Echoing the comments above, duct duct duct - there is absolutely no reason not to other than cost, but it's well worth it. We use 20mm semi-rigid corrugated conduit at work for small cables and it works great for single cables but you can get 54mm rigid "telecoms duct" cheaply eg https://www.drainagepipe.co.uk/telecoms-ducting-c-266/ which is good for mains plus some friends, without being huge and therefore expensive.

[JamesF]

3 minutes ago, discardedastro said:

The only other option I'd consider would be single mode fibre - this is a tiny bit more expensive but you can get this pre-made with ends on (the hard bit) from places like fs.com, e.g. https://www.fs.com/uk/products/29606.html - this is 100% futureproof and will let you run 1 or 10G, but it has the other huge benefit that it won't interact with power cables at all, and won't introduce any grounding issues, so will be much more reliable and simplify your wiring/grounding schemes. You use a media converter on each end (something like https://www.amazon.co.uk/ipolex-Transceiver-10-1000Base-Tx-1000Base-LX-Single-Mode/dp/B078RMXPGX/ref=sr_1_6?keywords=media+converter+fibre+single+mode&qid=1574981101&sr=8-6) to turn it back into copper Ethernet, so none of your kit needs to use fibre.

This is almost certainly what I'd do if you aren't exporting the house earth connection to the observatory and having a local one instead.

James

[discardedastro]

15 minutes ago, JamesF said:

1 hour ago, Carbon Brush said:

 

Need to be careful with the terminology here, because cat5 and cat5e are theoretically not the same (the standards are different), though anything sold as cat5 these days is almost certainly cat5e anyhow.  My understanding is that cat5e is good for gigabit ethernet at cable lengths up to 100m otherwise it doesn't conform to the cat5e standard (though I'm aware that some people suggest you don't try to run them that far and I'd be tempted to use fibre over that sort of distance myself).  In some situations auto-negotiating interfaces will drop down to 100Mb/s (perhaps if the cabling run is longer than 100m and thus can't support the signalling rates required for gigabit ethernet or if the cable is damaged).  If you want 10Gb/s then you do need cat6 (or cat6a for runs longer than about 50m).  I have cat5e cable runs in the house that get up to more than 40m and carry gigabit ethernet quite happily.

As someone who does telecoms standards for a living, you're about right! 5e is good for 100M, but only if it is a straight 100M link directly into equipment at each end. The second you introduce patch cords, you introduce loss - Ethernet is just radio, so if you're familiar with the concept of loss in cabling for satellite/ham radio then it's the same principles. Connectors == Loss. So sticking a switch straight on the end at each end is fine (since the switch "ends" the 1G-BASET physical signalling segment, or PHY, and creates new ones for the other connectors). The 100M number also relies on perfect install - no damage to the cable through excessive bending, torsion or tension. Over 100M in ducting, things like tension start to come into play, and without using things like swivelling pulling socks you can introduce torsion easily and damage things. That's not something fibre's immune to, either.

5 won't do a gig except at short lengths.

5e (what most stuff you'll buy in Currys/Amazon will be) will do a gig to 100M in theory and 70M in typicalpractice.

6 will do 100M in practice, but 10G in theory.

Fibre will do kilometres without breaking a sweat at 1G, 10G or 100G (if your optics budget extends to it).

In all cases, the PHY layer will negotiate the fastest rate it can. Sometimes, this negotiation ends higher than it should - so you might get a gigabit link negotiated but only be able to push 500Mbps before you start seeing CRC errors, frame loss etc. The only way to validate the installed performance of a cable is with a certifier (which is basically a specialised test source/spectrum analyser - again, this copper stuff is all basically radios) or a transmission tester (which will just try shoving data around and see how it goes). Both bits of kit are very expensive, sadly, so most people (even a lot of professionals) don't do it - £1-2k will get you a transmission tester, £10k is entry level for certifiers. However, you can do a transmission test yourself with a PC at each end and iperf3 between the two.

Fibre is a different beast but the same principles apply. If you didn't break it during install over that distance using singlemode you'll be fine - either it'll work or not at all. The margin for soft faults is pretty tiny, and over 100M I've seen live circuits working over horrendously broken fibres!

Edited November 28, 2019 by discardedastro

[Physopto]

For your cabling consider using large bore(3/4") blue fresh water  pipe. It is tough as heck and less likely to leak than drain pipe as there will be no need for joints. Even if hit with a shovel or fork it give amazing protection to any cable. You can buy it in lengths around 100 feet or more quite easilly. It is cheaper than drain pipe as well. You can bury several pipes along side each other each taking one or two cables. Keep the mains separate from the signal cables and a foot or so apart from them. To get cables through them dust with talcom powder and pull through, if they are very pliable, if quite stiff you may be able to push them through, it depends upon your judgement and capabilities. You can blow a small item through attached to a thin cord, or even vacuum it through. Then use that to pull your cables. 

Just remember that mains cable has to be at least 18", or 50 cm  under the ground and have a marker tape along its length buried with it. If you go for above ground mains cable it also must comply and be over 2 metres above ground I believe. Check that one!r

Derek

[JamesF]

@discardedastro Thanks, that's a very useful summary.

James

[ollypenrice]

Is all this cabling necessary? Couldn't you just put power into the observatory and run the imaging rig on a PC located in there. I would go for a basic old desktop machine with plenty of USB ports, probably bought 'reconditioned second hand.'  This should eliminate hubs. (I host six robotic telescopes and we have more trouble with hubs, either astro-dedicated or normal, than with any other product.)

You could then control the observatory PC from the house via Team Viewer or Any Desk. Although you need two computers to do this I think it would be cheaper and, possibly, more reliable than the long-cabled alternative.

Olly

Edited November 29, 2019 by ollypenrice
Typo

[carastro]

Agree with suggestions posted above.   I am no expert with electricity, but I got an electrician to install armoured cable to the observatory with it's own fuse box so if anything trips outside it doesn't affect the house.   Inside the observatory there is an RCD protected box as well.   This is all for mains electricity supply. 

I also had cabling installed for internet connection, but never got it to connect reliably, so now have a laptop in the observatory and connect to that remotely indoors via Teamviewer as Olly suggested.

I normally stay with the rig until everything is up and running OK.  Then I retreat indoors and use Teamviewer. 

Carole 

Edited November 29, 2019 by carastro

[JamesF]

How does Teamviewer in the house connect to the computer in the observatory?

James

[carastro]

Via Wifi James.  Sorry should have said.   I had to get my WIFI hub moved from the front of the house to the back to improve the Wifi signal and now I stick the hub on the window sill of the back window when I am imaging. 

You can get wifi extenders if you have a problem, but luckily I didn't need to do that. 

Carole

Edited November 29, 2019 by carastro

[Nigella Bryant]

2 hours ago, ollypenrice said:

Is all this cabling necessary? Couldn't you just put power into the observatory and run the imaging rig on a PC located in there. I would go for a basic old desktop machine with plenty of USB ports, probably bought 'reconditioned second hand.'  This should eliminate hubs. (I host six robotic telescopes and we have more trouble with hubs, either astro-dedicated or normal, than with any other product.)

You could then control the observatory PC from the house via Team Viewer or Any Desk. Although you need two computers to do this I think it would be cheaper and, possibly, more reliable than the long-cabled alternative.

Olly

Thanks Olly and Carole. I love simple, all that can/needs/suggested is mind boggling. I think the two computers and team viewer sounds interesting. 

Edited November 29, 2019 by Nigella Bryant
Added comments

[ollypenrice]

I made the suggestion because an increasing number of guests using our observing sites for their own equipment use this system nowadays. Old muggins here is the only one outside!

Olly