What do I need to expent temperature sensor cable?

[rumleyfips]

Neil:

Vic has most of the numbers.  The 5 PV panels in series will be ~150v, 8.5 at no load. I had planned on  35 ft. of 2/10 wire from the junction box to the controller.

My original thought was 30 ft 2/10 from the controller to the batteries. Lots of headroom and reasonable voltage drop I thought.

The 96 v.nom. battery bank with #4 wire , the #4 wire to the inverter ( 8 ft), the 65 ft. 2/12 to the sub panel ( 114v , 20 amp fuse)and the 75 ft 2/12 to the turbine (2K, 3 phase, wild AC, diversion at 120v) have worked for a couple of years. I have checked the wires with an infared thermometer and seen no heat rise under load.


Thanks:
John

[niel]

now i'm all confused here.

"the battery bank bounces between about 52.4 and 58.8 volts once the first Classic finishes absorb."

that does not indicate a 96v battery bank. i was addressing only from the classic to the battery bank so humor this old man and give it straight as i asked for it.

[rumleyfips]

Neil:
I think the voltage "52.4 to 56.8" is from another thread about absord discrepancies between controllers.

In the system I am planning, I have exis cting and tested equipment. Two seperately switched battery banks 96v nominal each- concisting of 8- 12 volt/110AH gel batteries. A 96 volt-2000 watt inverter, a transfer swith and subpanel and connecting wiring. All powered by a 2k wind turbine.

I plan to install 5-245w PV panels ( ~150v OC, 8.5 amp, 50 ft. 2/10 connecting wire and a 250KC Classic. I want to put the controller where I can monitor the screen. This leaves 30ft. between the battery bank/inverter and the classic. I thought 2/10 wire would give less than 1.5% voltage drop.

The house is 50 ft. long , with the turbine wiring coming into the extreme south east end . The battery bank, turbine controller  and inverter are right there. The entrance panel and subpanel are 40 ft towards the other end of the house.

The PV panels will be mounter on the south western part of the roof, 50 ft from the battery bank.

The controller will go inthe middle of the house where I can see it: 30 ft of wire to the panels, 30 feet to the batteries.

It has been suggested here that I move the battery bank and inverter closer to minimise voltage drop and also that the voltage drop with 30ft. 2/10 will cause no problem.

Hope this is clear.

Old! My wife told me she thnks I'm to old to be up on the roof installing racks and panels.

John

[niel]

ok, now i understand. i ran the calculations and running #10 for 30ft both ways would more than suffice for the output from the classic with those 5 245w pvs. the current will look like about 10.65a from the classic output to the batteries and will have about a .4v v drop for about .42%. you could double the pv string and still be under 1% from the cc to the batteries. the difference was that the voltage output was high allowing for a smaller gauge wire to be run 30ft. i did not figure on any other aspect of the system as i was concerning myself with the cc to batteries wire run, but i would imagine it to be similar for the pv run as well because even though the wire length is longer the voltage is also higher so imo you are good to go.

the battery bank to inverter i can't be sure of as far as v drops go and depends on the current drawn, the wire gauge used, and the distance at that 96v. you are asking of the temperature sensor wire going 30ft and i think it was asked once long ago about that having a long distance and should probably be ok with the longer telephone wire. if i'm wrong on that, i'm sure one of the guys at midnite will spank me for it.

[rumleyfips]

Thanks to all who helped with advice. I'll go ahead and if it doesn't work , I'll change things around until it does.

John

[rumleyfips]

I just thought of something when I was trying to get the ABS light on my truck to go out.

I could use a dead battery within reach of the supplied cable and get the temperatures from it. My basement has a low ambient about 54F and high in the mis 60's. Battery temp doesn't seem to vary much with charge, dischard, rest or weather.

John

[niel]

although your temp doesn't vary much, the actual temp is still far enough off from the 77 degree standard to be affected. if you are fine with that it does not vary much then you could just add like about .1v to the charge stages and call it approximately correct. to me i would rather have the bts help to accurately determine the best voltage setting after inputting the appropriate voltage deviation into the classic.

[rumleyfips]

Our basement has a dirt floor( earth coupled ) and stays cool enough to use on hot summer days. I take the furnace fan door off, turn the fan on manually and get ~66F air circulating. Today I threw some woood in because nights are still cool here in Nova Scotia. Thge batteries have come from 55F to 59F this morning as the house went from 60F to 68F.

I will need to compensate because the batteries will never see 77F. The BTS will be used.

John