Best Way??

[nvreloader]

I have 4-Canadian SC6P-220w Panels with the following spec's,
Pmax=220W
Voc =36.60V
ISC =8.09A
VMP =29.30V
Imp =7.52A
Voc-coef =0.1281V/C
Noct =45.00C
15A fuse rating/series

Per actual measurement of the roof/dimensions, the farest run of the panel cables (10ga/MC4 connectors) will be 15/20' max into the area where the controller, a Tristar-MPPT-60a,w/ battery temp gage will be mounted.

Should I run all 8 cables (4 panels) down the reefer vent area into the electrical bay and tie them into a neg/pos buss bars, then run WHAT sized wire to the controller??

Is there a better/easier way, to route all these panel wires?

I am taking this in small steps, so I can understand it.

Tia,
Don

[BFL13]

150/6 =25, so how cold when 22 is 25?

If V co-efficient is -0.36% /degree C,(like my Sharp 130w) then where that % of 22 is 0.08v, then 3v diff is 3/0.08 = 37.5 so unless I lost a decimal place somewhere, that would be 25-37.5 = -12.5C

[2oldman]

I don't know what 'cutting is close' is, but I've had 6-12v panels at 22.1voc on my Outback 150vdc controller for a year. I'll let you know if it blows up.

[BFL13]

One second or less time of being over Voc and you fry the controller. Very expensive! Yipes!

The instructions warn to adjust your expected panel Voc for temperature where the 150v limit is taken at 25C (warm!) to the coldest temps you expect to be camping in (the panel Voc rises as it gets colder) so use the spec temp vs voltage co-efficient to get that.

Then leave a bit extra margin just to be sure.

On the wire gauge go as fat as you can within price reason. If #8 will do but #6 is available for not much more money, use the #6

[mena661]

146V is definitely cutting it close. Keep it series/parallel for the array.

[CA_Traveler]

2oldman wrote:

nvreloader wrote:
Tristar-MPPT-60a,w/ battery temp gage will be mounted.

Is there a better/easier way, to route all these panel wires?

Looks like that controller is good to 150vdc PV input. By far the easiest wiring is 4 panels in series with just 2 small wires to the controller.

NO! NO! NO! 36.6V*4=146.6V. Those specs are for nominal conditions. Typical variations include edge effects and temperature changes - try serial and you'll blow the controller.

There are controllers that derate for over VOC but don't exceed 150V for the MS MPPT 60 controller.

[time2roll]

Put panel pairs in series and use the parallel connectors to combine from 4 wires to 2. Then use #8 MC4 cable to the controller. Use a 2 wire strain relief on the top of the fridge vent. Just 2 wires going down.

[2oldman]

nvreloader wrote:
Tristar-MPPT-60a,w/ battery temp gage will be mounted.

Is there a better/easier way, to route all these panel wires?

Looks like that controller is good to 150vdc PV input. By far the easiest wiring is 4 panels in series with just 2 small wires to the controller.

[CA_Traveler]

Using the Y connector means that you will double the amps on that 10' section of wire resulting in higher loss. You may be OK with that approach.

I would either use a combiner on the roof and say 8 gauge wire to the CC or just run the 4 10 gauge wires to the CC. So 20' of 8 gauge plus combiner vs 40' of 10 gauge.

[nvreloader]

Thanks for the info, Guys

Which of these types of connectors would be the best for combining the panel wires down to the CC, the wire size will be 10ga to the CC.

See info here:
http://www.ebay.com/itm/One-Pair-MC4-Type-PV-Solar-Cable-Y-Branch-Connector-FFM-MMF-TUV-/190782130077?pt=LH_DefaultDomain_0&hash=item2c6b80479d#ht_4103wt_1204
-----
http://www.ebay.com/itm/3-Pairs-Solar-Panel-Cable-MC4-T-Branch-Connectors-Splitter-Coupler-Combiner-USA-/251364785056?pt=LH_DefaultDomain_0&hash=item3a86823ba0#ht_540wt_810

The wire run/length from the CC to the 4-GC batteries will be a max distance of 10' or less, and since the MS CC can use #2 awg cables, that is what I will be running to keep the losses at the minimum etc.

The reefer duct is the center point of the panel lay out and a straight shot down to the OEM electrical bay where all the wiring comes together etc, in this TH RV.

Ca Travler,
between family deaths, drawing a sheep tag (34yrs trying) + 4 other family members drawing tags and a full remodel (inside/outside)of the home front per orders from the better half, then drawing a prized Bull Elk tag (35yrs trying), + 5 family tags, (All works stops to fill the tags), all the inside stuff is stored inside the shop with NO ROOM to do anything, plus working 4+ months away from home, there don't seem to be enough time to do anything, if you know what I mean.

I am making some head way, now!!

Tia,
Don

[CA_Traveler]

Wire size to the battery depends upon the distance. Use the wire size in the manual.

Is the refer the only/best option for wiring? What about cabinets/closets etc?

I thought you finished this project years ago???

[CA_Traveler]

nvreloader wrote:
Per info from the MS string calcuator for my panels,(if I entered the correct info) the panels will be 2 panels in series and 2 strings in parallel.

Tia,
Don

The calculator is right - 4 in series would exceed the controller VOC.

You won't gain much using a combiner on the roof and is likely not worth the extra work. Just run the 4 wires to a disconnect and controller.

Leave the roof panel connectors disconnected until all wiring is complete. Be safe with 70V.

[westend]

I would use a rooftop combiner box and use one run of two wires down to the controller. Even if you chose to run all eight or four down to the controller, they will have to be ganged either on a bus, at the controller's terminals, or at a common interrupter before the controller.

By using a combiner box you'll have the opportunity of less wire loss and can use a manual circuit breaker before the controller. The latter makes it easy to remove power from the modules to the controller and rest of the system when working on the 12V system.

I made my own combiner box and I should make them for the market since the solar folks want a pretty fair amount for them. They are just a weatherproof box with bus terminals inside.

[big_buford]

So you should end up with 4 cables at 70+ volts. Sounds like a nice system have fun!

[nvreloader]

Per info from the MS string calcuator for my panels,(if I entered the correct info) the panels will be 2 panels in series and 2 strings in parallel.

Tia,
Don

[mena661]

Are they going to be wired in series or parallel or a mixture of both (say 2 pair in series, that pair wired in parallel to the other pair)??