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Topic: RV garage (Read 4522 times) previous topic - next topic

Re: RV garage

Reply #40 –
Quote from: Sven and Kristi –
We are still  going through the permitting process with the city on our garage.  Because this  is a high fire hazard area, I had to get an endorsement from the fire marshal (we were on a strike team together in '03) with regard to set back from the property line and house.  Not only with my structure be metal and stucco (non combustible), but I also have install a sprinkler system, which requires me to change out the water meter to a 1" line ($1800).  The final dimensions will be 20'x44' and just under 15' tall with 12x12 with a manual sectional roll up door.
 I will put a sub panel in that will allow for 30A  and some 20A outlets.  Has anyone had experience wiring a detached garage?  Presently I have a 30A outlet at the house (outside garage wall) that I use for charging the coach.  I plan to put in a junction box there and running wire underground (22" deep if I remember).  The distance will be about 25'.  Will 10ga wire do?  I need to put something down for the permit and will get an electrician later.
There are several voltage drop calculators online I did 120 single phase AC, 30 amp load, in copper wire at 25ft length and it says there is 1.172 volt drop with #8 and a 1.864 drop with #10. I hope that helps.

Re: RV garage

Reply #41 –
You might want to rethink this a bit, here's why.  As far as tying onto an existing outlet with a junction box, you will need to remove the existing outlet unless it's wired for an extra 30 A capacity, unlikely.  If possible, I'd recommend coming off your service panel with a new circuit, 50 amps.  The difference in cost will be minuscule compared to 30 and utility will be much greater.

You will need an electrician involved, might as well get him over there to evaluate and give details for permit. 

Re: RV garage

Reply #42 –
Sen,  like I said at the start use 8ga wire.
JohnH

Re: RV garage

Reply #43 –
Foundation has been postponed for a few days due to unseasonal rain.  Regarding the electrical hookup, we are still waiting for a meeting with an SDG&E rep. to get approval for upgrading our panel.  There is an issue of the panel being located just above the gas meter (no longer meets code), but we might at least get an updated, if not upgraded, panel.  The present 30A wiring will be replaced with  appropriate wiring for the supply and distance.  We aren't cutting corners on the project, since that usually results in problems or limitations later.

Re: RV garage

Reply #44 –
Hopefully if the rains are heavy and lots of it you have not dug the ground for the footings. Heavy constant rain will soften the base of it meaning it will not be suitable for concrete to be poured unless adding gravel or? To strengthen that base.
JohnH

Re: RV garage

Reply #45 –
Always use a larger size cable, why not run 4 wire #6 to allow for 'future' choice changes that could include 50-amp and almost eliminate any voltage drop.

Re: RV garage

Reply #46 –
Wire size depends on the distance from main panel to sub panel as it is run, not a straight line, not the distance from one building to another.  My barn is less than 8 ft from the garage where the main panel is. Wire length was more than 80 ft.  Bigger wire than the minimum for the amps and distance is always a good choice.

Re: RV garage

Reply #47 –
I will put in my 2 cents.  If me I would run 3 # 4 & 1#8  copper wire to a small panel in your new building. Install a 80 or 90 amp breaker in your main panel.  Add a 50A plug near where your coach power will be when in the building with 3#6 & 1 #8  to a 50A breaker .  Then add some 120v outlets with 3-12g wire and put on 20 amp breaker. Make sure the plugs are gfi protected. 

With the panel in your new building it will allow you to add more outlets at a later date.

Re: RV garage

Reply #48 –
Check your local electrical code.  A sub-panel in your outbuilding will probably have to have its own main breaker.  Generally the main breaker in the sub panel and the breaker in the main panel should be the same size as I recall.  Electrical codes may be different where you live as may the rules about getting electrical permits and inspections. Wire sizes are specified by amps and length.  No guessing allowed.

Re: RV garage

Reply #49 –
I'm relying on the judgement of an electrician to put in the supply line and subpanel.  A city inspector will ensure that it is up to code.  My main reason for going with a pro is that I don't want to mess with the main panel.  SDG&E got back to me, denying any improvements to the original (obsolete) panel because of the proximity to the gas meter.  If I want to put in a new (exchanging "like for like") panel with new circuit breakers, I will be subject to the current code and move the panel about 4' away.  The only exception is if it is an emergency due to a dangerous situation.  I explained that as a firefighter for 30 years, we took preventative measures, rather than wait until it became an emergency.  I also added that if I ever had an electrical fire at the panel in the future, I would be talking to them (inference being "through a lawyer"), since they denied my attempt at improving the safety of the panel.  They are going to get back to me on this.

Re: RV garage

Reply #50 –
Total bullshit I am sorry whatever DA came up with the sh** rule is totally ignorant about reality of the very very narrow combustion.window of gaseous mixtures at the same time a spark might occur from defective panel. Engineers reign supreme over code inspectors and fire department officials (AHJ's)  as clearly stated in any code as an engineered design. AHJ's typically have only a high school degree and minimal amount of continuing education classes put on by guess what, various vendors while they consume their steak and lobster dinner. If you want a real eye opener read the limitations on the $$$$ life safety devices such as fire/smoke dampers. End of rant. Overly prudent engineers design terraplanes, real engineers design airplanes.

Re: RV garage

Reply #51 –
I would like two fingers of whatever phred is having please. Neat, no ice. Thank you.

Re: RV garage

Reply #52 –
Calm down Phred.  We may not agree with all of the rules but we have to comply if we want to move forward in a timely manner.  I did all of the structural calculations for my barn from soil loads to footings to wind and shear loads, headers and trusses. I submitted all of this to the building inspector who was impressed.  It was a pretty good working relationship after that.  I think they respect builders who know what they are doing.  If you treat the inspectors with disrespect you are going to have a hard time getting your project done.

By way of disclosure I have been a real engineer by training and practice for more than 50 years.

Re: RV garage

Reply #53 –
Back to the wire size and subpanel issue. 3% voltage drop is normal for conductors downstream of panels. Panelboard wire size are based on  CB size to protect the wire. Probally never see max load or voltage drop only after an extended power outage. Circuit breakers are sized as the MAXIMUM OVERCURRENT PROTECTION DEVICE (MOCP) or MFS maximum fuse size. To try to protect the end user this is based on inrush current. Wire size is typically based on the MCA rating to a appliance. This is known as diversity. Is it safe to have 42 20 amp breakers in a 200 amp panel yes. Ignorant AHJ
or installing contractor may tell you otherwise.

Re: RV garage

Reply #54 –
"Overly prudent engineers design terraplanes, real engineers design airplanes."

John Dillinger and Baby Face Nelson drove Terraplanes.
Terraplane - Wikipedia
 

Re: RV garage

Reply #55 –
Quote from: coastalbuilder –
I would like two fingers of whatever phred is having please. Neat, no ice. Thank you.
It is what it is, AHJ's can't respond to that question honestly maybe a problem there based on other $$$$$$ influence, we don't offer that period.