seasonal tilting ground mount

[TT]

Hi Steve,

After a recent lightning strike we have fitted a few of these
http://www.apc.com/shop/us/en/products/APC-ProtectNet-standalone-surge-protector-for-10-100-1000-Base-T-Ethernet-lines/P-PNET1GB
No connection to company.
Just unplug, short pigtail supplied and connect to a local earth.
Under £30. Works with gigabit connections

[eabadger]

thanks for thinking of me, but i already have these on the network cables and an rj11 version on the adsl line, plus i have them in the consumer unit.
last near strike we had tripped the main rcd at the solar shed, when reset the adsl box would not light up and the power supply was dead, i am guessing a spike was halted by these devices and killed the psu?
the adsl was then very slow and in the end orange upgraded our live box, didnt fix issue but better box, the final fix was a new overhead cable, maybe just a dodgy connection but they fitted about 2km of wire anyway.

steve

[eabadger]

bit of an update on the batteries getting hot and a terminal coming loose, all now ok on that terminal but another then got warm, the connecting lead got very hot, so i removed and cleaned and did notice lead when off seemed "crunchy" put all back together and still got hot, measured resistance of lead when loaded and was 10 times more than other leads, and had a .4v volt drop over it, at charge of 125a no wonder it was hot, made a new conector with 50sq cable and 10mm lugs, now all ok few.
investigated lead and when i opened up insulation the copper was very dark, without rubber covering on tug separated two halfs, old age? badly made who knows, i have fluked all leads now and tested for crunchyness and all are fine, overnight minimum voltage a good 1.5v up on normal and battery voltage on heavy load, dishwasher or heat pump not bad at all.

fingers crossed, and check your leads, my fear after the mppt dyeing when battery's disconnected and solar still on could have happened if lead had let go under charge or load.

steve

[biff]

Hi Steve,
       I know that you are well aware of the dangers of forklift cells etc, You had one pop the excess gas lately and it must have been a horrible experience.
The normal route that these cells take if housed in their metal tank, is straight up,skyways with the sides of the cells bursting out and spraying acid all over 360%.
 I have been in conversations with a few people that this happened to. I recall two brothers who were working on a forklift battery to replace a cell, They had the whole area flooded, with the caps removed and were unscrewing the connections when a cell blew skyways  and hit the inside of a box profile roof, 20ft above, leaving a large dent in it. One brother caught the other and pulled him outside to a barrel full of water and stuck the upper half of his body in it, The smoking lead came down all over the shed like napalm, They hired out 100s of electric forklifts. One went into their office and came out with a motor cycle helmet with the big clear full visor and said that that was what they wore after that occasions.. It was an excellent lecture and I never forgot it. They had taken all the normal precautions that day,flooding the cells and only using insulated tools , It was a job these two had done dozens of times before,but this day a cell blew right between them. The only conclusion that they could come to was that the cell had shorted internally..There was absolutely no humor involved in this conversation, it had happened some 4 years previously and they still got the jitters thinking about it. They could not understand why the whole battery did not explode in a chain reaction. I wear goggles, cap, hood and old heavy clothes when I go to top up my 60 cells. I also have a barrel full of rain water and another half cage tank full of water. One next to my large bank and the other just outside my shed door. I have a lot of respect for them .
It might be possible that there is some other than normal reaction taking place inside one of your cells. I have no idea how you would find that out apart from taking voltage readings like you are doing at present. The motorcycle helmet with the full clear visor would be the only thing that could protect both the face and the head from the falling lead, It was the brothers own idea and a very good one.
                                                                        Biff
 Rogerico has massive experience in these cells and has actually rebuilt them and got them working. Perhaps if he is about he could advise us.
 

[eabadger]

i now treat again very carefully is used to watch the battery men rebuild them at GEC and at an airport i worked at.
i think my issue was the leads and i took for granted the ready made ones would last a lifetime, how the wire broke internal is beyond me, i will post a picture, logic defies why it happened, all other leads same cross section and all fine, it is obvious looking at colour of copper that it had been hot and then the chain of hot cold on and on make the condition get worse, but what was initial cause? my guess is when it was crimped it was not perhaps right or acid has somehow got in to the sealed insulator.
whatever my lugs are now soldered and pressed as they used to be the original from excide were just pressed.
135a going in at mo and all terminals less than 26*

the hydrogen pop was awful, live with me a while, i also have water to hand and an a&e nurse/sister for a wife.

steve

[eabadger]

 
not visible until i cut insulation, colour wrong as in been hot repeatedly but for how long.
result was overheated terminal and then that went loose  which exasperated issues.

[todthedog]

Blimey!

[eabadger]

the why has been bugging me....
they must make the leads straight? but all forklift banks i have seen have the half moon shape leads as bent out? is this to suit different cell sizes?
but to my latest theory, if made straight then bent to fit the outer wires must be under constant stress?
the bank was still working fine, but under high load or high charge this lead was getting warm, no visible sign until i cut it open, just sounded crunchy which when opened it certainly was!
my ir thermometer has come in handy, now all cells are the same as are all leads, so maybe a one off or maybe others are about to go? must order more 50/10 battery lugs in case i have to replace them all.

might be worth checking when doing watering?

steve

[Scruff]

the why has been bugging me....

Flat bar won't do that. 

[eabadger]

scruff, what flatbar do you use? copper?
Had another lead bite the dust, not as drastic, just under load or charge greater than 3kw the lead got hot and was crunchy, issue i have with untined copper spacers i have made is verdigris externally, all seems ok and have cleaned and vasalined, but may remake and tin?

[Scruff]

Copper in enclosures. Aluminium in the elements. Tap it with a drill when I need to (soft metal).
 I don't vaseline my terminals I just clean them when I service them. Less mess in the long run.
CSA = L x W.

Tinning..eh never bother electroplating the stuff....maybe a potential dump load idea in there. 

[eabadger]

what bar size did you go for? you got forklift cells?
when watering cells, the slightest drip on the copper spacers makes them verdigris, hence reason for next stripdown i think i will tin them all.

steve

[Scruff]

Glue lined heat shrink?

75mm² for 200A peak nominal load. 3mm x 25mm.
Slightly more for aluminium because it's not as good a conductor.

DC travels through the conductor. The verdigris isn't an issue as long as the contact surface is clean. Skin effect is an alternating current thing.
 
I haven't got forklifts. Golf carts, FLA starters, AGM standby, VRLA are the major share of my lead host.
I would get forklifts if my AGMs weren't free.

[eabadger]

is the Sq section not calculated the same as wire then?
could try heatsink but will not see what is going on so think i will tin them up.
i see peaks of 230a if wife forgets to use one thing at a time!
dishwasher and kettle or daft fancy coffee maker are favorite!

i was working at a big hotel a few years ago installing a new system, same week they paid a company to take out the UPS batteries, all gell with date stamps of less than 12 months old, i tried to buy them but was told no, they paid £20 each to get rid of them, this ups was huge, gutted.

steve

[Scruff]

My AGMs were discarded (I offered scrap prices) from a static inverter insurance replacement in a theatre to give 4 hours 110V lighting in emergency. They were 18kWh I split with a friend tested monthly after 3 years service. Bar the first & last in the string they're all tippy top.

CSA is calculated for insulation melting point...if you don't have any it's discretionary.  
In your case 3mm x 40mm bar or 4mm x 30mm will suffice.


Transparent glue lined heat shrink?