Got electrical questions? I have answers! - Page 2

Plasma · 10-03-2014, 05:21 PM

Quote:

Originally Posted by DaveLind

Helping a friend with the electrical on a Aerotech shuttle bus. I can usually figure out most thing with electrical systems, ie... Wiring, switches, etc... I plan on using a 12 volt dc and 110 volt ac prebuilt panel, 30 amp. I have yet to look at the fuse box for the shuttle, but I'm assuming nothing will work with out the key in the ignition. So any circuit I use (existing lights) I will remove the breaker and disconnect the feed wire then hook into the new system, going through the new panel. Couple if questions. I've been looking at surge protectors which seem really expensive. Is there anything out there that is reasonably priced and resettable? (Under seventy five dollars). Is there any way to make my own with off the shelf breakers? I'm not using gfci breakers but instead gfci outlets. It's the cost issue. Thanks, and this is a great forum.

I dont exactly understand if you are talking about the 110v breaker panel, or the 12v vehicle fusebox when you refer to the ignition key. I will answer best I can.

There is a bit of a difference between the devices people usually refer to as surge protectors...
The breakers in the 110v panel protect from overcurrent. That is, if a device draws too much power from the circuit (usually because something went wrong) the breaker shuts off to prevent the wiring from catching fire, or the malfunctioning device catching fire. In a sense, it is a current surge protector.

GFCI is to prevent from the device shocking people. In an AC system, there's 3 lines (as most may know) Live, Neutral, and Ground. Ground is literally attached to the ground (or the bus frame in your case). When working properly, all power that flows from the Live line should flow back in through Neutral. If someone standing in the bus touches the Live line, or if water touches it, or if it touches the bus frame, some power will not flow back through neutral, and the GFCI detects this and shuts off.

An actual surge protector is really a voltage surge protector. It's job is to kill the circuit if the voltage gets too high. A voltage surge can be caused by a malfunctioning utility transformer, or a lightning strike. Most surge protectors are meant to short-circuit when the voltage gets to high, thereby destroying themselves in a valiant sacrifice for the good of every electronic device plugged into a wall at your house. They are not resettable, but their sacrifice will not be forgotten.

So no, you cannot make a surge protector with breakers, GFCI, or otherwise. They are apples and oranges.

In a bus, you wont have to worry much about utility transformer failure if you are operating off the grid. Similarly, lightning strikes are not a big deal (surge protectors really only protect if lightning hits the power lines). Unless you are lightning-prone, and plugging in expensive electronics, I wouldnt worry much about surge protectors. GFCI is, in my opinion, more of a luxury on a 110v system. It will save you from getting a nasty (but non-lethal) shock if your wires get messed up, or if you spill water on an outlet. Having breakers is far most important but that's obvious to most. If you still want voltage surge protection, try looking for "MOV surge suppressors". They will burn out over time from small surges, or all at once with a lightning strike, but they are pretty cheap to replace.

Plasma · 10-03-2014, 05:32 PM

Quote:

Originally Posted by pictureLOVE

I was realllly excited to find this thread... According to the mechanic who worked on it, our bus (apparently) had its electrical mangled by the previous owner. I completely lack the vocabulary to name the parts - would it be OK to just post a picture?

Sorry, but a picture of mangled wires probably wouldnt help much (give it a try anyway though!) I've dealt with similar problems before. I'm fixing a fishing boat now. The wiring is a rats nest, and it's not even worth trying to sort it out. In my experience, it's usually far easier to redo the wiring entirely. If that sounds like a big job, it's because it is. The key is to sort out which wires are the essential ones, and which are for random crap like indicators, and dashboard lights. The wiring in my boat is still a rats nest, but it runs and drives. Only three wires to the engine. One cranks it, one kills it, one sends power back from the alternator. Once you start there, you can either figure out the rest of the wires, or redo them entirely, but it's not as daunting a challenge when you can at least drive, and have done some process of elimination.

Ponyracer · 10-04-2014, 08:25 AM

Does anyone have GOOD wiring for dummies diagrams of how to wire a schoolbus? It would be nice to find clear wiring diagrams you could lay on top of each other with diff colors that had different systems, shore power, batts, solar, dual alts, generator etc.

I have a basic idea of how things work but it would be nice to have visual confirmation and also WHERE in the system things go.

I know I'd buy one.......anyone?

The Nebuchadnezzar · 10-21-2014, 08:55 AM

Hi Ponyracer, I could use one of these too.

64north · 01-19-2015, 07:02 PM

Hey there,
I am re-wiring the rear heater in my bus, and I am curious if you know about the types of switches used. This one is a three part switch (OFF, LOW and HIGH), and on the back I'm guessing there is a positive, negative and ground connection. I know which one the ground is, but I am not sure which is positive and which is negative. Heres a picture, do you know if the side labeled "RED" is the positive side? The middle is the ground.
Thanks!

bansil · 01-20-2015, 04:22 AM

If it is off/lo/hi
And only 3wire
None are grounds, with switch off 1lead will be hot, flip to lo and 2will be hot, and switch to hi 2will be hot

One will be hot all the time, this is power in

Check with multi meter

My .02

Curious what else is fed with switch, there are 2leads with 2wires each

64north · 01-20-2015, 05:57 AM

Well the middle black wire comes from each of the 8 switches and goes to the top part of the fuse box. They aren't connected to anything, it looks like a ground, I will take a picture tomorrow. The other two wires (Left and right in the picture) go to each side of the switch on the heater (I assume positive and negative). But even the switches that are only a 2 part (ON/OFF), still have that black wire (middle) going to what I assume is a ground.
Not going to lie, I know nothing about electric, so I am not sure if there is a positive and negative side to the heater or not.
Let me know what you think
Thanks

bansil · 01-20-2015, 08:41 AM

I don't know, a multi-meter would

for a fan to have two speeds you need a resistor, high would bypass resistor 12V and low would use the resistor to change voltage say 8V= 2 speeds

so resistor is either built into switches or at fan

the 2 wires on each terminal is odd, where do they go?

64north · 01-20-2015, 02:02 PM

Thats a different switch, the heather is on the opposite side, just couldn't get my camera in there. Its the same exact switch and only has one wire coming off each terminal. Like I said the middle wire goes to what i assume is a ground, and the end terminals each go to the heater.

This is the actual switch, the blue wires each go to the heater and the middle black wire goes to...

Heres where the black wires go from each of the switches. Looking at it yesterday, I figured they were grounds, but it looks like something different. The black wires from the middle terminal all go to the top row there...

headinthetrees · 01-20-2015, 02:40 PM

Nice to have you here on the boards, welcome.

I'm an electrician myself, but almost all my experience is in 120-277v ac wiring. I like to help where I can, but nice to have someone more knowledgeable than I around to provide definitive answers.

bansil · 01-20-2015, 07:04 PM

Great picture, your black wires are "hot" they all connect to circuit breakers (they won't blow like fuses, they reset)

So the black 12v form breaker, goes into your switch which looks like a high amp/resistor switch so one lead will be a different voltage than the other to control fan speed.

Notice 8 gage wire feeding the bar connecting all the circuit breakers together?

That powers everything attached to those breakers.

On tablet what was question again? Lol will check later

bansil · 01-20-2015, 07:05 PM

Ugh hate tablets at times

64north · 01-20-2015, 08:19 PM

Basically the question is, does it matter which terminal wires I connect to the heater fan? (Obviously not the middle wire). There is a red and black wire on the heater, which I assume are positive and negative, but I'm not sure.
The wires coming off right now that go to the heater are identical, so theres no way to track them through the wire bundle. So does it matter which terminal off of the switch I connect to the heater fan?

These are the wires coming off of the heater. I checked the circuit with a multi-meter and it checked.

charles_m · 01-20-2015, 10:33 PM

From my experience, you should see if connecting different leads to the fan motor to 12v yield different speeds. In my bus, I think the motor used different sets of windings--one for low and one for hi. Both were sent 12v and, interestingly, would spin the same direction regardless of the polarity of the voltages I sent them! Didnt know you could do that. Im not sure if many switches use resistors to give a low speed. Most fans I see have some way of making the low speed built into the motor. Experiment! As long as the potential current is low--small ga wire--you probably wont kill yourself ;)

claydbal · 01-21-2015, 05:04 AM

Quote:

Originally Posted by charles_m

From my experience, you should see if connecting different leads to the fan motor to 12v yield different speeds. In my bus, I think the motor used different sets of windings--one for low and one for hi. Both were sent 12v and, interestingly, would spin the same direction regardless of the polarity of the voltages I sent them! Didnt know you could do that. Im not sure if many switches use resistors to give a low speed. Most fans I see have some way of making the low speed built into the motor. Experiment! As long as the potential current is low--small ga wire--you probably wont kill yourself ;)

yep. my heater like that grounds through the chassis and both wires get 12vdc positive. like you said, its for the two speeds.

op, you need a couple more hose clamps.

bansil · 01-21-2015, 07:59 AM

mine has a wire from screw on top of heater to the chair rail for the ground

HolyBus · 02-11-2015, 08:38 AM

O.k. Lets get back to basics.
Did someone come up with a how to diagram in color with the overlays? If not, is there a dummy's guide out there? I have two new eu2000i watt gasoline gens that can run together or separate. I don't have/plan for solar and no gas. Just 12v and 110. I want the option for using shore power. It seems like mine will be basic compared to some.
A diagram would be great! How do I power the box/switch that will separate the gens from the shore power so my outlets can be powered from the box/switch rather than straight from the generators?
Thanks for any and all help!

Dragonpop · 02-12-2015, 01:00 AM

It's probably best to know if you are going for 30amp or 50amp shore
power as one is wired as straight 120volt (30amp) and the other is two
120volt circuits combined to make 240volt (50amp). Either way they will
require a transfer switch, which can be manual or automatic, your choice
or budget. It basically switches your main power input between generator
or shore power. 30 amp uses three wire shore power cord and 50 amp
uses a 4 wire shore power cord. HTH

HolyBus · 02-12-2015, 08:44 PM

I'll run 30 amp shore. Sounds like I just feed the gen 30 amp output to the transfer switch and then to circuit breakers, then to the outlets. The transfer switch will have a second input for 30 amp from shore. I guess I was making it too complicated.
Thanks,
Bob

Seroflorus · 02-14-2015, 09:39 AM

running two 8D batteries (1100CCA ea) to start/run TC2000 (cummins). here's the problem...batteries totally drained (wouldn't turn on the meter) after two weeks of sitting. Recharged at napa (yay!) likely a parasitic load and have meter to chase it down but need to resolve cable issue first.

so, the bus had a new alternator, batteries and looks like 'new' grounding cable assembly about 6 mos prior to our acquisition. Now
1. wondering about cable assembly (looks stetchy as in too short, poor soldering job, questionable post sizing). shoddy work leads me to question whether what I'm looking at is even correct. For example, BB manual says use cable spec'd to SAE J1128 wondering if 2/0 SAE J1127 (as is currently installed) is really different from SAE J1128 and

2. where the heck to find correct replacement (pref preassembled unit but will go with cable by the foot) .

3. also, how to tell if the terminals fit given that the napa website shows terminal measurements. (although I could contact napa on this one)

and finally,

4. where the hockeysticks is the fusebox in a tc2000?

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