What do I need to expent temperature sensor cable?

[rumleyfips]

I need about 30 more feet of cable to hook up the temperature sensor and I don't know what to search for on ebay ( 72,000 listings for data cable).

Does anyone know what keywords I should use?

Thanks:
John

[Halfcrazy]

Well the temperature sensor is standard phone cable so you should be able to by a Female to Female adapter of the correct number of pins and the length cable you want.

Ryan

[boB]

Are your batteries REALLY 30 feet away from the charge controller

That is very far for battery cables.

That length is not normally advised unless loads from inverters connected
to those same batteries are fairly low.

boB

[niel]

not to mention that if the voltage drop between the classic and the batteries is high enough that your batteries may not reach full charge. the classic may see for example 14.5v while a 2v voltage drop (16.67%) would show 12.5v on a 12v battery bank. even a 1v v drop (8.33%) would not be too good and roughly a 1% or less v drop % should be sought between the classic and batteries.

[nigel]

Neil isnt it the other way round and the Classic would over charge. If the battery was actually at 14.4v with the voltage drop from the long  cable run then The Classic would see less V say 13.4v and continue charging in bulk, or have I missed something I usually do.......... always learning

Nigel

[vtmaps]

Neil isnt it the other way round and the Classic would over charge.

Niel is correct.  The classic would put out 14.5 volts, but the resistance in the wires would cause the voltage to drop so that the batteries received a lower voltage.  The classic has no idea what voltage is actually reaching the batteries.

Some charge controllers have an extra set of wires that run to the battery and measure battery voltage.  That way the controller knows what the battery is receiving and can adjust its output accordingly.

BTW,this whole issue of voltage drops can also occur with properly sized, short, thick battery cables.  It usually occurs because of a bad connection (bad cable crimp, loose connection, or corrosion).  It can cause the batteries to be undercharged or even cause a fire because of the heat that builds up in a high resistance connection.

--vtMaps

[rumleyfips]

Ryan -  the cable on ebay - thanks.

boB: One way or another the runs are lengthy.

I have a Chinese turbine 75 feet from the house. Wires off the coils are #10. the wire down the tower (supplied) is 20 ft. of #12. &5 ft. of #12 to the controller. The diversion relay closes at 120v( controlling 2 of the 3 phases. The 10a relay and #14 wire in the dump load have both burned in a hurricane and have been beefed up.

The 8x12 battery bank (~110 AH) is configured with #4 wire. Battery bank to inverter ( 120v, 20a) is #10 and the wire to the sub panel is  65 ft. 12/2.

I get 114v at the sub panel and use at least 16 a. The inverter kicks off on high limit if if I try to start the furnce fan ( 13-14a) with 3-600 watts of household stuff operating.

There are 2 battery banks with switches. One will be for wind and one for solar. Not automatic but cheap.

I have 5 245 watt panels to hook in series ~150 v , 8.5 a no load). There is 30 ft of supplied #10pv cable to the juntion box. Off the roof to the controller is another 30 ft. I plan /10 or maybe 8. From the controller to the batteries is 36 ft. and /10 or 8 is planned.

No matter what I do I will have parts a long way apart. I could move the battery bank or the classic but not the turbine, pv the panels or the sub panel. I don#t think juggling locations will help much and , of course, I pray to the great god expediency.

Thanks for the interest and if I#m being dumb please stomp.

Thanks:
John

[nigel]

VT thanks for that so the classic would then never go in to absorb or float because the battery would never rise to 14.4 volts due to the voltage drop in the cable., so the only way around this would be to read the actual battery voltage and slowly adjust the bulk voltage setting till the battery was actual reading is 14.4V and the Classic drops in to absorb mode. ?

[Halfcrazy]

One thing to mention is that slight voltage drop between a controller and batteries will usually take care of itself. When we are in Bulk and cramming a bunch of amps there may be voltage drop there say the controller sees 59.2 but the batteries are really 59 as the charger goes into Absorb and the current drops off the voltage drop will drop as well so as the Absorb cycle continues the voltage drop will become less and less and the 2 usually agree by the time Absorb is done. This is of course based on a minimal voltage drop to begin with.

Ryan

[Vic]

Nigel,

In the case cited by niel,  the Classic would go into Asorb,  and probably Float,  as,  as VT noted,  there are no Kelvin -- battery vlotage sense leads on most CCs,  including the Classic.  This is due to the drop in the cables from the CC to batt,  the CC does not know what the real batt volatge is.

And rf,  your serpentine system can have problems steming from long leads of all kinds.  These issues can result from noise signals being induced into some wiring,  from currents in other wires.  The BTS cable carries a low level signal,  and COULD be disrupted by currents in other leads.  This is why it is recommended that the BTS cable not be run with other wiring that could have high current (pulses etc) flowing.

If the system were mine,  would try to get many more of the components located closer together.  Barring that would run the BTS cable and any other low level signal/control wiring in a separate METAL conduit.

I do not fully comprehend the exact layout of your system,  but looks like your battery banks run at high voltage which will reduce the currents.

PLEASE BE VERY CAREFUL WITH THE HIGH VOLTAGES IN YOUR SYSTEM.  DC VOLATGES CAN BE MUCH MORE LETHAL THAN AC AT THE SAME VOLTAGE.   HV DC often causes muscle contractions,  and it can be very difficult to release from the connection.  And, even small DC currents flowing through your heart can stop it.  High DC voltages cause more current to flow (generally).  DC is wicked stuff,  especially at voltages above about 60 volts.  It is said that DC voltages above about 1,000 V often cause charing of the flesh,  which can help limit the current,  and so on.  You probably know about the precautions to use around highish DC V,  but, ...

Good Luck,  Vic

[rumleyfips]

Vic:

Thanks for the safery concern.

I could move the battery banks about 20 ft to be within 6 ft of the Classic. This would put the turbine 105 ft away but we are in a mediocre wind spot so wind is secondary. Moving the inverter with the batteries is easy and would have little effect one way or the other. I can`t get the solar panels much closer than 40 ft.  That way the Classic, wind diversion and dump, inverter and batteries would be in the middle. The sub panel and transfer switch would be 30 ft closer to the inverter.

So much for the bad news. The good news is that my ghastly looking homemade solar panels charged my conversion ride on mower and I mowed the lawn today.

John

[boB]

The deal with the Classic knowing the actual battery voltage which can be false because of wire
voltage drop is usually like Ryan Mentioned...   At Absorb voltage, the current is lower and so
the voltage drop is way less...  UNLESS the CC is putting out almost full current because of loads
and the voltage drop is still a lot.

That being said, in the future, the Classic CAN know the battery terminal voltage without
extra wires.  This can be done by calculating the voltage drop across the wires as long
as the wire length and gauge is entered.  Because the Classic would know the resistance
and it already knows the current, this can be done similar to how battery temperature
compensation is done now.  (Auto-IR-Comp) It would  most likely be mixed in with that voltage modification
from temp-comp.

boB

[rumleyfips]

Neil:

When I use an online calculator, I get:

150v DC, 12 amp, 30 ft. copper, 75F- 2/12- 1.2%, 2/10- .8%, 2/8-.5%.

According to what I read these figures are acceptable.

Is this correct?

Thanks:

[niel]

what is your battery bank voltage? wire gauge? wire run length? max current expected and don't confuse this with the max current ability of the classic as it can only output from what is available on its input (ie a 12v 12a pv may go to 13 or 14a on the output to the battery and not 96a which is the classic 150s top end rating)?

[Vic]

Hi niel,

Post #6  has quite a lotta data about the setup, 
"The 8x12 battery bank (~110 AH) is configured with #4 wire. Battery bank to inverter ( 120v, 20a) is #10 and the wire to the sub panel is  65 ft. 12/2".

So looks like a nominal 96 V batt bank,  therefore,  these voltage drops (I have not run the numbers from the OP's last post,  above),  do not seem too great.

Vic