RV Trip Planning Discussions

Go Back   iRV2 Forums > RV SYSTEMS AND TECHNOLOGIES FORUMS > Going Green
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
 
Thread Tools Search this Thread Display Modes
 
Old 05-04-2020, 12:03 PM   #1
Member
 
GyroGypsy's Avatar
 
Winnebago Owners Club
Join Date: Aug 2019
Location: Crawford CO
Posts: 78
Chinese may make good firecrackers, but not good circuit breakers!

Went for our first real-world one day boondocking experience anticipating limited use of A/C. Outside temp was about 90 F during the day, and the A/C felt pretty good for about 45 minutes at lunchtime. Our solar array was making about 25 amps (600W) of the total 70 amp draw, thus the Tesla batteries were supplying about 45 amps of the required current. Then the Multiplus inverter choked as the 300 amp Chinese circuit breaker tripped.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

We went home, and I checked that the breaker would always immediately trip at 150 amps, and would also trip after spending time at lower levels.

Bussman or Eaton/Cooper breakers are unavailable at 300 amps. I found one similar form-factor breaker from Mechanical Products at 250 amps, but was only rated at 15 V. All I can find are similar low quality 300 amp breakers, and all have Amazon user comments that mirror my findings. I have a 300 amp ANL fuse and holder on order now.

Anybody else have experience or suggestions on this issue? I know many say "always use a fuse" - but do I have a choice?
__________________

__________________
2018 Navion 24D
800W Solar, 10kWh Tesla Coach
Gyrocopter Toad
GyroGypsy is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 05-04-2020, 12:08 PM   #2
Senior Member
 
Winterbagoal's Avatar
 
Join Date: Mar 2017
Location: Sarnialabad, Peoples Republik of Canuckistan
Posts: 1,317
Maybe a local welding shop might have some idea?
__________________

__________________
2018 (2017 Sprinter Cab Chassis) Navion24V + 2016 Wrangler JKU (sold @ ????)
2016 Sunstar 26HE, V10, 3V, 6 Speed (sold @ 4600 miles)
2002 Roadtrek C190P (sold @ 315,000kms)
Winterbagoal is offline   Reply With Quote
Old 05-04-2020, 12:20 PM   #3
Senior Member
 
Xmcdog's Avatar
 
Join Date: Dec 2019
Location: Nova Scotia
Posts: 606
Check with the local electrical supply warehouses. odd amphereage though.
Your local electrician should be able to help.
I gave up on the Chinese electrical parts many years ago. No I don't shop at Wally World either.
__________________
Jeff and Annette Smith
04 Glendale Titanium 2924. Fifth
2011 GMC Diesel 2500 HD
Xmcdog is offline   Reply With Quote
Old 05-04-2020, 02:57 PM   #4
Senior Member
 
Join Date: Feb 2018
Posts: 706
I don't use any DC breakers bigger than 60 amps. I use a 500 amp catastrophic fuse on my Spartan 2200 watt pure sine wave inverter. It can surge to 6600 watts. My inverter cables are 4/0.
__________________
Jeff--
Arctic Fox 22G w/1440 watts solar/GMC2500HD Double Cab with Leer Cap w/300 watts solar
astrocamper is offline   Reply With Quote
Old 05-04-2020, 03:49 PM   #5
Senior Member
 
Join Date: Jul 2014
Posts: 21,942
Your AC only draws 7 amps @ 120 volts ?

How did you get 2/0 or 4/0 cables on the 1/4 inch studs of that breaker. They must give off some heat under load.

Use a big heavy gauge fuse.
twinboat is offline   Reply With Quote
Old 05-04-2020, 04:00 PM   #6
Senior Member
 
Join Date: Feb 2018
Posts: 706
My Coleman-Mach 1 PS (power saver) uses up to 9.5 amps of 120 volt power when compressor is on. I run it on low auto. My old Mach 3 used closer to 16 amps.

I used 650 amp 5 stud bus bars with 3/8 inch studs, 500 amp DC fuse, 600 amp disconnect and 500 amp power shunt inline with the inverter/battery system. Each 100 amp-hour battery was connected directly to the 600 amp bus bars using 2/0 cables. The cable from the 600 amp bus bars connected to the shunt or disconnect using 4/0 cables. The inverter connected the system with 4/0 cables.

The 60 amp breaker/disconnects are not in line with the inverter. They go to smaller 400 amp bus bars and handle the breaker/disconnect duties for my 100/50 MPPT solar controllers.
__________________
Jeff--
Arctic Fox 22G w/1440 watts solar/GMC2500HD Double Cab with Leer Cap w/300 watts solar
astrocamper is offline   Reply With Quote
Old 05-05-2020, 09:35 AM   #7
Member
 
GyroGypsy's Avatar
 
Winnebago Owners Club
Join Date: Aug 2019
Location: Crawford CO
Posts: 78
Thanks for the many replies, guys. I realize that I did not mention the 24 V buss used due to the Tesla batteries, nor the AWG used and short wire run lengths. I did not think they were important as the weak CB appears to be the culprit.

Bottom line, so nobody is using a high current circuit breaker, just fuses?

Twinboat - Not sure how you arrived at 7 amps at 120 VAC for my air conditioner. It starts running with 9.5 amps at 120 VAC, and raises a bit with elevated OAT.

Per the wire gauge suggestions, my 24V buss uses copper bus bars and 1/0 AWG wire (@ 53.5 mm2 and 150 A rating). The total distance is less than three feet from the battery thru bus bars to the Victron Multiplus 24/3000, thus total run of less than six feet. Per Victron 24V installation guideline, a 50 mm2 wire is spec'ed for up to 5 M (~16 ft). I don't think wire size is the problem, but thank you all for suggestions based on what your own systems use, although you did not state your voltage either. Victron also spec'ed use of 300 amp protection device. I suspect this high values is likely for instantaneous current. Normally circuit protection is sized to protect the wire, not the device.

Winterbagoal & Xmcdog - I don't think any welding nor electrical contractors have experience with protecting high current DC circuits. But I live in the stix.
__________________
2018 Navion 24D
800W Solar, 10kWh Tesla Coach
Gyrocopter Toad
GyroGypsy is offline   Reply With Quote
Old 05-05-2020, 10:03 AM   #8
Senior Member
 
Itinerant1's Avatar
 
Join Date: May 2017
Location: Itinerant
Posts: 536
If your using an 12/ 24vdc inverter than it will be more amps than if running from a power pole 120vac. I believe is what he's asking.
__________________
2010 Carriage Cameo F34CK3
1,280w solar, 12v500ah
Itinerant1 is offline   Reply With Quote
Old 05-16-2020, 02:52 PM   #9
Member
 
GyroGypsy's Avatar
 
Winnebago Owners Club
Join Date: Aug 2019
Location: Crawford CO
Posts: 78
Quote:
Originally Posted by Itinerant1 View Post
If your using an 12/ 24vdc inverter than it will be more amps than if running from a power pole 120vac. I believe is what he's asking.
Still not sure what you (both?) are asking. The (120VAC only) air conditioner draws about 1100 watts at 120V, or ~9 amp AC load. The 24V inverter is about 90% efficient when used, thus is using ~1200 W at 24V, or ~50 amps from the battery.

The 24V to 12V converter is not being used at all in this use. That is only used for the DC-only compressor refrigerator, lights, and Murphy bed.

Shore power, or power pole, is also not being used in this instance.

Hope this makes better sense! Meanwhile a 300 amp ANL fuse is working just fine, with spares handy. Have reservations for our first lakeside camping venture since the Covid lockdown in another week.
__________________
2018 Navion 24D
800W Solar, 10kWh Tesla Coach
Gyrocopter Toad
GyroGypsy is offline   Reply With Quote
Old 05-17-2020, 01:55 PM   #10
Senior Member
 
Join Date: Apr 2019
Posts: 344
Glad you have it working. I'm curious, how many kWh's do you have in your Tesla battery?
Mtn. Lion is offline   Reply With Quote
Old 05-18-2020, 02:45 AM   #11
Member
 
GyroGypsy's Avatar
 
Winnebago Owners Club
Join Date: Aug 2019
Location: Crawford CO
Posts: 78
I am only charging to 85% of rated capacity thus expect a 9 kWh yield. Untested as of yet.
__________________
2018 Navion 24D
800W Solar, 10kWh Tesla Coach
Gyrocopter Toad
GyroGypsy is offline   Reply With Quote
Old 05-18-2020, 09:21 AM   #12
Senior Member
 
Join Date: Jul 2019
Location: Fulltimer
Posts: 206
Quote:
Originally Posted by GyroGypsy View Post
I am only charging to 85% of rated capacity thus expect a 9 kWh yield. Untested as of yet.
Also since it isn't a true 24V battery, you will hit a LV cutoff at some point before depletion with Victron equipment. Typical Tesla cells are usable for 4-4.5kWh/ea, so with two cells you are looking at 8kWh to 9kWh at best when used safely (not charged to 100%).

For your breakers, MidNite Solar and Outback both make high amperage DC breakers. I use a MidNite MNEDC250 in my system, rated at 250A at up to 125VDC. Outback part number for the same spec is PNL-250-DC. As far as I'm aware, you can't find 300A+ but 250A should be sufficient for your system. With Tesla cells, you may go as low as 19V which is where a surge would surpass the 250A capacity, hence the 300A recommendation. At 19V you are good for a surge of 4750W. I use breakers for everything and all throughout my system. No fuses.
__________________
2019 RAM 3500 Longhorn HO/AISIN 4x4 CCLB DRW | 2015 Keystone Alpine 3730FB | 2020 JLUR
Heavily modded, but 2925W solar, 22.8kWh LFP, and mini-split AC are my favorite mods
Perpetually "done" building our idea of the "perfect" off-grid FT rig
n0arp is online now   Reply With Quote
Old 05-20-2020, 11:05 AM   #13
Member
 
GyroGypsy's Avatar
 
Winnebago Owners Club
Join Date: Aug 2019
Location: Crawford CO
Posts: 78
Quote:
Originally Posted by n0arp View Post
Also since it isn't a true 24V battery, you will hit a LV cutoff at some point before depletion with Victron equipment. Typical Tesla cells are usable for 4-4.5kWh/ea, so with two cells you are looking at 8kWh to 9kWh at best when used safely (not charged to 100%).
Please detail any "safety" issues pertaining to fully charging this battery. I am not fully charging just to prolong battery life, although I can only imagine its replacement costs will decrease as the years pass. I have a 20V cut-off for all loads, which is well above the Victron lower limit. I am about to run a kWh test for each battery separately, just to ensure they are well balanced.
__________________
2018 Navion 24D
800W Solar, 10kWh Tesla Coach
Gyrocopter Toad
GyroGypsy is offline   Reply With Quote
Old 05-20-2020, 11:17 PM   #14
Senior Member
 
Join Date: Jul 2019
Location: Fulltimer
Posts: 206
Quote:
Originally Posted by GyroGypsy View Post
Please detail any "safety" issues pertaining to fully charging this battery. I am not fully charging just to prolong battery life, although I can only imagine its replacement costs will decrease as the years pass. I have a 20V cut-off for all loads, which is well above the Victron lower limit. I am about to run a kWh test for each battery separately, just to ensure they are well balanced.
20V is roughly 30% SoC on your Tesla cells. You're losing 30% of the 5.3kWh capacity right off the bat. You let that drop to 19V, that'll be closer to just 15% according to the discharge chart I've seen floating around.

Click image for larger version

Name:	Screen Shot 2020-05-20 at 22.28.29.png
Views:	3
Size:	184.9 KB
ID:	286237

The safety issue isn't charging to 100%, it's overcharging them. Your BMS overcharge protection circuit should limit charging to something less than 100%, in order to negate any regulation issues. 85% would be extremely conservative for these purposes.

So if your LV is set to 20V, you've reduced your 5.3kWh by ~1.6kWh.
Then, if you're only charging to 85%, you've reduced that by another ~0.8kWh.
You now have reduced a 5.3kWh cell to less than 3kWh.

If you instead set LV to 19V, then charge to 95%, you have closer to 4.23kWh usable. That's the 4-4.5kWh range I mentioned, which is based off of conversations with other people who are actually running these.

I will say that I've never run them personally, but ruled them out after extensive research and talking to several users. So most of what I'm providing here is a mix of speculation based off of my own research, and discussions with actual users. YMMV. I'd actually love to hear what results you come up with in your tests.
__________________

__________________
2019 RAM 3500 Longhorn HO/AISIN 4x4 CCLB DRW | 2015 Keystone Alpine 3730FB | 2020 JLUR
Heavily modded, but 2925W solar, 22.8kWh LFP, and mini-split AC are my favorite mods
Perpetually "done" building our idea of the "perfect" off-grid FT rig
n0arp is online now   Reply With Quote
Reply

Tags
breaker, circuit breaker, fire



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Circuit breakers are off but the water heaters work? larliebler RV Systems & Appliances 7 11-17-2018 06:28 AM
General Guardian RV 5500 Circuit Breakers Tripping - Driving and Not Running vettenuts Class A Motorhome Discussions 8 06-06-2018 02:28 PM
12 volt Circuit Breakers Bikedaddy MH-General Discussions & Problems 5 01-09-2010 10:14 AM
where is fuse panel / circuit breakers turbodogs Damon 8 09-20-2007 04:53 PM
110 electric power...15 amp circuit breakers Cocoa Loco RV Systems & Appliances 4 01-03-2007 05:48 AM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 09:48 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×