mcm991 Posted August 16, 2015 Share Posted August 16, 2015 In my continued efforts not to go broke, I was wondering if I can use NYY-SWA cable directly in the ground or just in yellow pipe to go from street to MDB? If you add up the cost of 200m of 4 core 95 mm2 NYY cable plus 200m of 3" hdpe pipe ..... you'll find the price of a decent sailboat. I was hoping to use SWA cable in order to save the cost of the pipe. Anyone know if the local boys who have to sign off on the install will let me do it? The cable is spec'd fine for direct in ground installation but I've never seen it done here ... mainly because nobody uses it. Thanks in advance. Link to comment Share on other sites More sharing options...
Crossy Posted August 16, 2015 Share Posted August 16, 2015 Thai Yazaki NYY-SWA is rated for direct burial, check out the data sheet here (download the .pdf) http://www.thaiyazaki-electricwire.co.th/product.php?id=61 What you do on your side of the meter is mostly your problem, you should be able to persuade your local PEA chaps that it's good to go. We decided against buried utilities after the 2011 floods. EDIT Black / red stripe HDPE should be low cost compared with the cable, if you use it you can use straight NYY rather than SWA, could end up around the same cost. Link to comment Share on other sites More sharing options...
mcm991 Posted August 16, 2015 Author Share Posted August 16, 2015 Thai Yazaki NYY-SWA is rated for direct burial, check out the data sheet here (download the .pdf) http://www.thaiyazaki-electricwire.co.th/product.php?id=61 What you do on your side of the meter is mostly your problem, you should be able to persuade your local PEA chaps that it's good to go. We decided against buried utilities after the 2011 floods. EDIT Black / red stripe HDPE should be low cost compared with the cable, if you use it you can use straight NYY rather than SWA, could end up around the same cost. Thanks Crossy. I'll do the sums. Good point about the floods. Will give that some thought. mcm. Link to comment Share on other sites More sharing options...
ksamuiguy Posted August 16, 2015 Share Posted August 16, 2015 200 meters is a long way! Link to comment Share on other sites More sharing options...
Crossy Posted August 16, 2015 Share Posted August 16, 2015 200 meters is a long way! Which is why he's using 95mm2 cable Actually, I'm wondering where his cable sizing came from, it does seem a bit over the top, could support 100A per-phase @ 5% volt drop. A big house. OP?? Link to comment Share on other sites More sharing options...
mcm991 Posted August 16, 2015 Author Share Posted August 16, 2015 It is quite a large house. Calculations were based on absolute maximum load requirements that are in reality unrealistic. Hence the 100kva transformer. But that is how they need to be made, I guess. I'd be much happier if I did not have a very long driveway ....... now. It seemed like a good idea at the time. mcm. Link to comment Share on other sites More sharing options...
Crossy Posted August 17, 2015 Share Posted August 17, 2015 Before buying anything I would do a proper maximum demand calculation including diversity, you may be pleasantly surprised. If you post the size and quantities of your energy hogs, aircon (include locations), water heaters, electric stove, irrigation pumps, small factory unit, we can do a quick and dirty calculation. Whilst there is nothing wrong in going oversize (other than cost) it seems silly to throw money away. 100kVA is a lot for even a really big home. Our absolute maximum demand all engines running is about 96A (single-phase). We are on a 15/45 meter and our 50A incomer has never looked like opening, maximum recorded current is about 35A. Link to comment Share on other sites More sharing options...
ksamuiguy Posted August 17, 2015 Share Posted August 17, 2015 A very difficult and expensive way to go. Might be cheaper to move the transformer. The cable you are proposing is good for almost 300 amps. Why armored? What was your was your total load calculation? Is this a commercial establishment? Link to comment Share on other sites More sharing options...
Crossy Posted August 17, 2015 Share Posted August 17, 2015 One other thing, what does your electrical contractor say regarding your required supply? Link to comment Share on other sites More sharing options...
mcm991 Posted August 17, 2015 Author Share Posted August 17, 2015 One other thing, what does your electrical contractor say regarding your required supply? My Elecrical contractor is almost out of his depth here.......... so I don't give his expert opinions much credence. The engineer who did the drawings is actually a reasonably smart guy who is fairly fresh out of university. I'm just afraid that his drawings are more in line with a final exam paper and not based on my reality. This is the MDB (attached). As you can see, there are several structures involved but I think the air con is the lions share of the load. The main house will use solar hot water and the stovetop is gas. The oven is 3000W. All the lights are LED's so nothing to worry about there. 2hp pool pump. Various pumps for water but nothing large. Having a really busy day but can post details this evening. Many thanks. mcm. (ignore the ATS for now ... I'll get to that whole issue later:) ) Link to comment Share on other sites More sharing options...
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