| Pages:
1
2 |
Santiago
Ultra Nomad
Posts: 3512
Registered: 8-27-2003
Member Is Offline
|
|
Question regarding electrical panel
This used panel is going in my small off-grid cabin. I will run the hot from the inverter thru a 60am disconnect and to one of the hot buss bars.
1. Don't I run a wire to the other hot buss bar as if the black and red in the photo were tied together?
2. This panel has a small ground buss in the upper left hand corner; I can't remember if I'm supposed to tie that to the neutral buss (black arrows
in the photo) or not and I get different info on the internets.
3. Came with two 20s and two 30s - aren't the 30s a little high for a small cabin - I was thinking of replacing them with 15s and using one of the
20s for the kitchen (all propane appliances). Are GFCI breakers the way to go or just use GFCI outlets in the kit/bath/exterior and run everything
thru those?
[img]http:// [/img]
|
|
|
woody with a view
PITA Nomad
Posts: 15939
Registered: 11-8-2004
Location: Looking at the Coronado Islands
Member Is Offline
Mood: Everchangin'
|
|
sorry. all i know about electricity is it is invisible and it hurts....
so, do'nt stand in a puddle when you tie in your GFCI's on the wet circuit!
|
|
|
msteve1014
Senior Nomad
Posts: 947
Registered: 12-2-2006
Member Is Offline
|
|
Hi Santiago,
Yes, tie the two busses together if you only have 120 vac to feed it with.
You do not need to bond the ground and the neutral busses together.
Yes, 30 amps is probably more than you need, you would be better protected with the smaller breakers, and most likely you will never trip one of them
if you are being careful about your power usage because of being on solar.
If you are going to buy a new breaker any way, check the prices on gfi breakers verses a gfi plug. They will both do what you want.
p.s. buy a ground rod if you do not have one yet, and bond everything to it.
[Edited on 2-27-2011 by msteve1014]
|
|
|
Santiago
Ultra Nomad
Posts: 3512
Registered: 8-27-2003
Member Is Offline
|
|
Thanks Steve: I also just realized that having a disconnect between the inverter and the panel is not needed - don't I just shut the inverter off?
I was going to make a ufer out of a 20' piece of #3 rebar (only size I ever see in BOLA) buried about 2' deep for ground - is this OK for ground?
|
|
|
Bob and Susan
Elite Nomad
Posts: 8813
Registered: 8-20-2003
Location: Mulege BCS on the BAY
Member Is Offline
Mood: Full Time Residents
|
|
the 60 amp breaker for the inverter is probably too big
most inverters are 33amp
so if you stacked 2 then the 60 amp would work
i'd run a 30 amp breaker on one
you can still run the 20 amp breakers
i would fill the box with breakers now...for use later
they are about 10 bucks each
do not connect the common and the ground
you could fry the inverter
remember the inverter is only circuit boards
edit...make sure you mark all the breakers
you will forget what's what later
[Edited on 2-27-2011 by Bob and Susan]
|
|
|
woody with a view
PITA Nomad
Posts: 15939
Registered: 11-8-2004
Location: Looking at the Coronado Islands
Member Is Offline
Mood: Everchangin'
|
|
deeper. on this side it's 5 feet deep. but that is 2010 code. prolly diferente in baja, where the draw is much less on the entire house.
|
|
|
msteve1014
Senior Nomad
Posts: 947
Registered: 12-2-2006
Member Is Offline
|
|
With the power you will be using you could use one of your 30s as a main in the panel and forget the disco.
The ufer would be ok, but the deeper the better with the dry soil i'm sure you have. Drive a piece of re bar as far in as you can and tie on to that.
|
|
|
RnR
Senior Nomad
Posts: 836
Registered: 5-1-2010
Member Is Offline
|
|
Don't forget - the breaker size determines the downstream wire size. Or vice-versa, the wire size determines the maximum size breaker. The intent is
to trip the breaker before the wire overheats and possibly arcs or starts a fire.
So, that said, 15 amp breakers require a minimum of 14 ga wire, 20 amp/12 gauge, 30 amp/10 gauge. Change those 30 amp breakers to something smaller
or you will have to wire everything with 10 ga wire!
Ex: 14 gauge wire is rated to carry a maximum of 15 amps without overheating. A downstream appliance could short, pull 25 amps, overheat the 14 gauge
wire, and never trip the 30 amp breaker.
|
|
|
BajaBruno
Super Nomad
Posts: 1035
Registered: 9-6-2006
Location: Back in CA
Member Is Offline
Mood: Happy
|
|
Good advise here. RnR says it right on choosing breaker sizes--it all depends on the load, which determines the wire size, which determines the
breaker size. But, nothing says you can't use 14g wire and a 15 amp breaker for a 5 amp load. However, if the load is much higher (not likely in
your solar cabin), then choose the right wire size first.
A GFCI won't work without a good ground. Woody and msteve1014's advise is good--drive that rebar straight down 8' or so and you should be OK. You
can do that by slipping a heavy piece of pipe (with cap on end) over the rebar and slamming it down. Outlet GFI's are much cheaper than breaker GFI's
and will protect regular outlets downstream. Don't use them on appliances--motors don't like them and it is unnecessary.
Whether the ground and neutral buss bars are tied together depends on the installation: main panel, yes; sub-panel, no. You are using a sub-panel as
a main panel, so I don't know, but it's probably a crap shoot.
Christopher Bruno, Elk Grove, CA.
|
|
|
RnR
Senior Nomad
Posts: 836
Registered: 5-1-2010
Member Is Offline
|
|
| Quote: | Originally posted by BajaBruno
Whether the ground and neutral buss bars are tied together depends on the installation: main panel, yes; sub-panel, no. You are using a sub-panel as
a main panel, so I don't know, but it's probably a crap shoot. |
Tie them together.
According to the NEC (National Electrical Code), all "separately derived power sources" are required to be grounded as close to the service entrance
(usually the main panel) as possible. The inverter is a "separately derived power source" equivalent to a power company's step down transformer on a
distribution line. IE: The source of the 120/240V power.
Household systems are to be grounded "at only one point". Usually the main panel. If a sub was connected and bonded, the nuetral and ground wires
will provide TWO return paths for the electricity from the sub to the main and current will actually be flowing in both the nuetral and ground wires
between the sub and the main. That is why main panels are connected and subs are not.
There is no real distinction between a breaker box designation as a sub or a main. It's just a metal box. The distinction is in how it is used and
wired. That's why there is a green bonding screw for use in the nuetral buss supplied with every new panel and a tag that says something to the
effect that "use this screw when equipment is to be used as "service equipment".
|
|
|
RnR
Senior Nomad
Posts: 836
Registered: 5-1-2010
Member Is Offline
|
|
If anybody wants to know how and why a GFI works, just ask. It's a little complicated but interesting. They are not overload devices, (breakers).
|
|
|
1bobo
Nomad
Posts: 116
Registered: 2-5-2010
Location: Mulege
Member Is Offline
|
|
| Quote: | Originally posted by BajaBruno
Good advise here. RnR says it right on choosing breaker sizes--it all depends on the load, which determines the wire size, which determines the
breaker size. But, nothing says you can't use 14g wire and a 15 amp breaker for a 5 amp load. However, if the load is much higher (not likely in
your solar cabin), then choose the right wire size first.
A GFCI won't work without a good ground. Woody and msteve1014's advise is good--drive that rebar straight down 8' or so and you should be OK. You
can do that by slipping a heavy piece of pipe (with cap on end) over the rebar and slamming it down. Outlet GFI's are much cheaper than breaker GFI's
and will protect regular outlets downstream. Don't use them on appliances--motors don't like them and it is unnecessary.
Whether the ground and neutral buss bars are tied together depends on the installation: main panel, yes; sub-panel, no. You are using a sub-panel as
a main panel, so I don't know, but it's probably a crap shoot. |
Why do you say appliances don't like GFI's? Not questioning your expertise, but rather my assumptions.
|
|
|
cj5orion
Nomad
Posts: 336
Registered: 2-6-2010
Location: Pacific Beach/Gonzaga Bay
Member Is Offline
Mood: time for a cervaza !!!
|
|
| Quote: | Originally posted by Santiago
Thanks Steve: I also just realized that having a disconnect between the inverter and the panel is not needed - don't I just shut the inverter off?
Use the extra breaker for a main disconnect.
There are times.... when you'll use it. |
Home Remodels/Builds..Recession!
Gone BAJA BUILDIN/FISHIN !
|
|
|
Santiago
Ultra Nomad
Posts: 3512
Registered: 8-27-2003
Member Is Offline
|
|
Is this how I make one of the 30amps a disco?
[img]http:// [/img]
Believe it or not, I'm a general contractor but the only thing I know about 'lektrical is to hire a good electrician and then hope the inspector
catches anything goofy. Of course, I DID have a cabin in Shaver Lake burn down following just this procedure.....
|
|
|
wessongroup
Platinum Nomad
Posts: 21152
Registered: 8-9-2009
Location: Mission Viejo
Member Is Offline
Mood: Suicide Hot line ... please hold
|
|
Of course, I DID have a cabin in Shaver Lake burn down following just this procedure.....
Santiago ...... still laughing...
[Edited on 2-27-2011 by wessongroup]
|
|
|
Bob and Susan
Elite Nomad
Posts: 8813
Registered: 8-20-2003
Location: Mulege BCS on the BAY
Member Is Offline
Mood: Full Time Residents
|
|
he question is...did you save "the box"
|
|
|
RnR
Senior Nomad
Posts: 836
Registered: 5-1-2010
Member Is Offline
|
|
| Quote: | Originally posted by Santiago
[img]http://[/img]
Believe it or not, I'm a general contractor but the only thing I know about 'lektrical is to hire a good electrician and then hope the inspector
catches anything goofy. Of course, I DID have a cabin in Shaver Lake burn down following just this procedure.....
|
No reason that this won't work.
Some cautions:
1. Might want to cover the exposed lugs/buss of the "A" side with tape or shrink wrap. Turning off the 30 amp/disconnect breaker to the "B" side
still leaves those "A" side terminals hot and exposed.
2. Putting breakers in those "A" side slots to cover them and then using those breakers in the future may lead to turning off the disconnect and
again leaving the "A" side breakers and circuits hot.
3. Do the next future owner a favor and put a note/tag on the breaker explaining the setup.
|
|
|
BajaBruno
Super Nomad
Posts: 1035
Registered: 9-6-2006
Location: Back in CA
Member Is Offline
Mood: Happy
|
|
| Quote: | Originally posted by 1bobo
| Quote: |
Why do you say appliances don't like GFI's? Not questioning your expertise, but rather my assumptions. |
GFCI's are designed to protect people, rather than wire, by tripping in the presence of even tiny amounts of current traveling to ground, such as
might happen if you touched a broken wire while you were grounded.
Some appliances create these tiny ground faults, either deliberately (such as a stove ignitor) or unintentionally (in a motor). They are not a shock
hazard in a well designed electrical system, but they will give you annoyance trips with a GFCI, which is why your refrigerator is not plugged into
one, and your garage has a single non-GFCI outlet for these type of appliances.
Most appliance manufacturers recommend against using GFCI outlets for their products. I hope this helps. |
|
|
|
msteve1014
Senior Nomad
Posts: 947
Registered: 12-2-2006
Member Is Offline
|
|
| Quote: | Originally posted by Santiago
[img]http://[/img]
Believe it or not, I'm a general contractor but the only thing I know about 'lektrical is to hire a good electrician and then hope the inspector
catches anything goofy. Of course, I DID have a cabin in Shaver Lake burn down following just this procedure.....
|
No, run the hot from the inverter to the 30 amp c.b. Tie the two hot buss lugs together, like we were going to do any way. Now both busses are fed
by the 30, and all the other spaces are switched by the 30 amp "main".
[Edited on 2-27-2011 by msteve1014]
|
|
|
Bob and Susan
Elite Nomad
Posts: 8813
Registered: 8-20-2003
Location: Mulege BCS on the BAY
Member Is Offline
Mood: Full Time Residents
|
|
why don't you get a better box with a place for a main cut-off
and then the breakers
cost about $30 usa at home depot includes breakers
|
|
|
| Pages:
1
2 |
![[*]](images/xmbforum/default_icon.gif){kind=icon}
