Early draft of PD4045 step by step

Anything electric, AC or DC

Re: Early draft of PD4045 step by step

Postby bdosborn » Sat May 14, 2016 8:46 am

H.A. wrote:Fwiw, When describing to electrical 'lessers', its better to never mention subject of AC grounding and DC 'ground' in the same paragraph (or page for that matter)
Treat & discuss them as the entirely different things what they are.


Why is that?

Bruce
2009 6.5'X11' TTT - Boxcar
Image
Boxcar Build
User avatar
bdosborn
Donating Member
 
Posts: 4212
Images: 450
Joined: Wed May 05, 2004 11:10 pm
Location: CO, Littleton

Re: Early draft of PD4045 step by step

Postby H.A. » Sat May 14, 2016 3:35 pm

Zzzz cc
Last edited by H.A. on Tue Jun 28, 2016 4:00 am, edited 2 times in total.
H.A.
The 300 Club
 
Posts: 428
Images: 0
Joined: Tue Nov 15, 2011 8:16 pm

Re: Early draft of PD4045 step by step

Postby bdosborn » Sat May 14, 2016 7:55 pm

H.A. wrote:Thats sort goes to the old saying, "If you have to ask, You wont understand".


Maybe, but it you truly understand how it works, you should be able to explain it clearly and simply. How about contributing to our understanding of the issues with two separate explanations that even a guy like me can understand?

Bruce
2009 6.5'X11' TTT - Boxcar
Image
Boxcar Build
User avatar
bdosborn
Donating Member
 
Posts: 4212
Images: 450
Joined: Wed May 05, 2004 11:10 pm
Location: CO, Littleton
Top

Re: Early draft of PD4045 step by step

Postby Bill n Robi » Sat May 14, 2016 9:14 pm

Great write up. Thank you. I plan on replacing the WFCO-8725 that came with my TD with the PD4045 and you helped answer a few of the questions I had.

One remaining question that maybe someone can answer. I have a charging circuit from my truck, where would that tie in?

thanks
2015 T@G Max
2015 Toyota Tacoma TRD Sport 4 Door Short Bed
User avatar
Bill n Robi
Teardrop Master
 
Posts: 226
Joined: Mon Dec 01, 2014 4:32 pm
Location: San Diego, Ca
Top

Re: Early draft of PD4045 step by step

Postby noseoil » Sat May 14, 2016 10:37 pm

H.A. said "They are different purposes. Negative ground of typical automotive DC circuits utilises chassis, etc. as part of the conductive path of normal operation. AC grounding is a conductive path for fault currents of AC circuits. Its not to be a current path for normal operation."

My question is this, do you ground the trailer frame to earth (& thus the other metal parts), when using 110 volts like shore power or a generator? If so, why? If not, why not?
Build log: viewtopic.php?f=50&t=60248
The time you spend planning is more important than the time you spend building.........

Image
User avatar
noseoil
1000 Club
1000 Club
 
Posts: 1278
Images: 66
Joined: Sun Apr 27, 2014 8:46 am
Top

Re: Early draft of PD4045 step by step

Postby H.A. » Sun May 15, 2016 11:32 am

[[[[[[
Last edited by H.A. on Tue Jun 28, 2016 4:02 am, edited 1 time in total.
H.A.
The 300 Club
 
Posts: 428
Images: 0
Joined: Tue Nov 15, 2011 8:16 pm
Top

Re: Early draft of PD4045 step by step

Postby bdosborn » Sun May 15, 2016 11:33 am

H.A. wrote:Hmm.
I think I just did.


Not really, how about something like this?:

Grounding the Frame

There needs to be a path from the frame to AC ground, in case a hot wire contacts the frame. Without such a path, a person entering or leaving the trailer could become the path to ground and be electrocuted. Run a green wire from the ground bus to the frame.


There needs to be a current return path from the frame to your AC power source. This ensures that the breaker opens if the hot wire ever comes in contact with the frame. Without it, the breaker wont open and the frame is energized at 120V. A person touching the frame would become the return current path and be electrocuted. Run a #12 green insulated wire from the ground bus to the frame. Strip the paint off the frame where you connect the wire so there's a good connection. Be careful not to connect the neutral and the ground together inside the converter. This can cause the frame to be energized if the campground receptacle has the hot and neutral reversed. Keep the neutral and grounds separate in all your wiring for the same reason. Its a good idea to carry a receptacle tester with you and check the campground receptacles to make sure the hot and neutral aren't switched before you plug in.

Grounding DC

This is controversial. Because all the DC goes through the converter, which is grounded via the AC ground wire, some say there is no need to ground the various appliances and fixtures to the frame. Others say that it is a must, but I’m not clear on why.


Bonding the battery to the frame is not as clear as the AC approach. Trailer manufacturers will use the trailer frame for the DC current return path to save money on wiring. A connection from the trailer battery to the frame is not needed when the trailer is connected to the tow vehicle as all the power for lights and brakes comes though the the trailer connector. A bond from the battery to the frame also provides the same function as it does with the AC system; it provides a return path for current to blow a fuse if a 12V positive wire touches the frame. Most people omit the connection to the frame if they're not using the frame as a current return path to the trailer battery as the risk of electrocution death at 12V is much less than at 120V. However, it's a good idea to provide the connection as it's an easy way to provide another level of safety in your electrical system. The green wire from the battery negative terminal to the frame should be the same size as the positive wire from the converter to the battery. And don't worry, stray AC currents won't charge your battery through the frame connection. The AC ground wire only carries current during a fault if you've installed your wiring correctly.

Bruce

P.S. There's a general perception among specifiers that tandem breakers are of lesser quality than single breakers, FWIW.
2009 6.5'X11' TTT - Boxcar
Image
Boxcar Build
User avatar
bdosborn
Donating Member
 
Posts: 4212
Images: 450
Joined: Wed May 05, 2004 11:10 pm
Location: CO, Littleton
Top

Re: Early draft of PD4045 step by step

Postby bdosborn » Sun May 15, 2016 11:45 am

Bill n Robi wrote:One remaining question that maybe someone can answer. I have a charging circuit from my truck, where would that tie in?


Just use one of the fuses in the converter. Make sure you use a big wire from the truck to the trailer. A #10 or larger. Voltage drop gets to be a problem over the distance from the truck alternator to the trailer battery. I would use a 30A fuse with a #10 wire. My truck had a #18 wire in the factory wiring harness and it was useless due to VD.

Bruce
2009 6.5'X11' TTT - Boxcar
Image
Boxcar Build
User avatar
bdosborn
Donating Member
 
Posts: 4212
Images: 450
Joined: Wed May 05, 2004 11:10 pm
Location: CO, Littleton
Top

Re: Early draft of PD4045 step by step

Postby H.A. » Sun May 15, 2016 12:39 pm

Zzzzz
Last edited by H.A. on Tue Jun 28, 2016 4:06 am, edited 2 times in total.
H.A.
The 300 Club
 
Posts: 428
Images: 0
Joined: Tue Nov 15, 2011 8:16 pm
Top

Re: Early draft of PD4045 step by step

Postby springdew » Tue May 17, 2016 1:15 pm

Wow, so much discussion. Thanks everybody! There will be a lot to refine for my next draft.

I've been away building. Soon as I get my roof panels screwed on, I'll be ready to rough in the electrical. So exciting!
For everything there is in this world, there is someone who likes it.
Planning and build journal for Yiayia's Waggon: At Home on the Road

Spring Dew Foulger
User avatar
springdew
Teardrop Advisor
 
Posts: 69
Images: 9
Joined: Tue Jul 07, 2015 4:09 pm
Location: Springville, UT
Top

Re: Early draft of PD4045 step by step

Postby TigerHawk » Tue May 17, 2016 8:19 pm

On figure 3 - Zac's Diagram - there appears to be an additional bus bar at the far right that includes an A/C hot to converter, and an A/C hot from the 2nd breaker (for the converter). My pd4045 has the A/C hot wire crossing from the DC side to the AC side. I was under the impression that this would just be directly connected to the 2nd breaker. The image leads me to believe there is another buss bar in there but perhaps I am seeing it incorrectly. Can you provide clarification?

Thank you
TigerHawk
Teardrop Inspector
 
Posts: 14
Joined: Sun Jan 31, 2016 2:36 pm
Top

Re: Early draft of PD4045 step by step

Postby H.A. » Wed May 18, 2016 1:47 pm

Zzzzzz
Last edited by H.A. on Tue Jun 28, 2016 4:07 am, edited 1 time in total.
H.A.
The 300 Club
 
Posts: 428
Images: 0
Joined: Tue Nov 15, 2011 8:16 pm
Top

Re: Early draft of PD4045 step by step

Postby Bill n Robi » Wed May 18, 2016 5:18 pm

Can someone let me know what the physical depth really is? I think the spec is including the bezel and I what to make sure I have enough room behind to mount it.

Thanks
2015 T@G Max
2015 Toyota Tacoma TRD Sport 4 Door Short Bed
User avatar
Bill n Robi
Teardrop Master
 
Posts: 226
Joined: Mon Dec 01, 2014 4:32 pm
Location: San Diego, Ca
Top

Re: Early draft of PD4045 step by step

Postby lrrowe » Wed May 18, 2016 5:31 pm

I would say about 1/8 in from memory. But you need to be concerned with having enough room at the back for the wiring, both AC and DC, to exit and turn if needed. Plus if you plan on installing the wires after the unit is installed, without much room to maneuver, that will be a difficult task.
Bob

First Post on Purchase of Trailer: http://www.tnttt.com/viewtopic.php?f=42&t=60722
Hot water infloor and radiator heating project:[url]http://www.tnttt.com/posting.php?mode=reply&f=54&t=62327[/

Image Image
User avatar
lrrowe
Donating Member
 
Posts: 3262
Images: 439
Joined: Sun Feb 10, 2013 5:54 am
Location: SW Virigina
Top

Re: Early draft of PD4045 step by step

Postby TigerHawk » Fri May 20, 2016 11:50 am

springdew wrote:[*]If no battery, run a wire from the negative bus bar you set up in Step 7 to ( … where? I haven't found this answer yet.)
[*]




This is the question I really need answered. I was not planning to run/use a battery at this time with my PD4045. So for the d/c lights/fan, I will bring all negative to a bus bar, and then where? If I had a battery, I would connect to the Negative post. What about if one is not running a battery?


The electrical may be the most difficult part of the camper yet because of my lack of knowledge of the area. I could always re-cut wood, sand out imperfections and such, but I certainly don't want a camper that's going to be my "electric bed." :?
TigerHawk
Teardrop Inspector
 
Posts: 14
Joined: Sun Jan 31, 2016 2:36 pm
Top

PreviousNext

Return to Electrical Secrets

Who is online

Users browsing this forum: No registered users and 3 guests