THSCC Forums

Well between a demanding new job and 2 kids I can't keep up with the bus power issues that are coming up and I'm looking for someone to step up and take over.

Apparently there are plans to buy a generator for the bus and I'd like for someone to volunteer to come up with a plan for implementation. I hear that this is to happen before Greenville.

The generator is going to require serious consideration about how to re-design the power system in the bus if it's going to work well and be sustainable. I have some thoughts about it and I'd be happy to give a brain dump to anyone who can step up to help.

Here's a quick run-down about how the 12v power system is currently set up:

- Bus has 2 12v batteries in parallel which are "dedicated" to starting the bus
- One "accessory" deep-cycle 100AH 12v battery is under the table inside for powering all of our on-site equipment
- When the key is on (acc or bus running) the accessory battery is connected in parallel to the charging system with a high-current relay
- During normal operation at events the accessory battery is disconnected from the bus batteries to prevent drain-down of the starting batteries. Switching the key to "Acc" (backwards) will recharge the acc battery off the bus batteries
- The accessory battery runs 3 main 12v power lines:
1. Right side power strips
2. Left side power strips
3. PA system subpanel
- Accessory grounds are to the metal rails under the table.

That's about it. Since the current power problems are relatively recent, I suspect that there is something wrong with the current system. There is a new battery under the table, but it is possible that the ground connections are deteriorating. So a clean-sheet design for 110v power may be in order if troubleshooting of the current system isn't going to be done. This means scrapping everything that isn't tested (because anything could be the current source of the problem).

Here's what I can think of for our power requirements:

PA
12v PA amplifier
12v PA mixer board
12v Wireless PA

Power strips
12v JAC box
12v Timer Display -- has a 110v adapter
110v Printer (plugged into invertor)
110v Computer (plugged into invertor)

For the generator, if 12v power isn't planned, we need to find 110v power adapters for the 12v stuff. It would probably be a good idea to run 110v power wires to the 3 locations and hard-mount power strips. Will probably want to put an exterior cord "dongle" or surfacemount male plug outside somewhere. If everything is switched to 110v permanently then the generator will always need to be on for even basic functionality (schools, announcements, etc). Or we could design a hybrid system if needed with some things still on 12v power and some on 110v. But the current problem with the 12v system still needs to be diagnosed in that case. Also need to look into storage options for the generator and fuel in the trailer, and plan some sort of emergency/workaround solution in case the generator is kaput or we run out of fuel.

Well that was most of my brain dump but I'd be happy to discuss more on the phone. It's too bad we have to scrap the current system since it served us well for 2 years, but hey I guess we need progress.

Volunteers?

Any thoughts about how the power system should be set up?

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Mike Whitney
whit32@gmail.com, 919-454-5445
V10, V8, V8t, I6, I6, V6, F4t, I4, I4, I4, I4, I2, 1, 1

I can't volunteer to take care of it (I've got two kids myself and the bigger issue is I don't make many TH events, plus my place for keeping the bus is FAR from centrally located...in fact I'm the absolute wrong direction), but I'll chime in on the implementation.

Many generators do both 12V and 110V. I think it makes the most sense to just insert a high current plug (Anderson Power Poles?) between the high current relay we have now and the internal battery. That way the current system is still in tact. Heh, he said "current."

Then make a 12V plug for the generator that can plug into this same plug to the battery side and then follow your plan for the 110V side of things. Then the generator keeps 12V on the battery and is what's going to actually supply the current, but the battery is there if the generator konks out due to needing fuel or whatever.

What would be nice from there is to leave the inverter system as a backup and do your power setup inside such that you can quickly plug into an inverter or the generator should the need arise. Then you have the best of both worlds, assuming whatever is wrong with the current system is fixed. That's not a necessity, though, since we use a laptop for T&S and in theory it has a battery that can handle the generator cutting off due to needing fuel or whatever...it's not likely you're printing when this happens and even if so that's easy to recover from, so I wouldn't worry too much about the printer. That said, this system would easily provide enough 110V current to now run a laser printer instead of an inkjet, so perhaps upgrading that, too, would be a good thing since the inkjet is pretty slow (and keep the inkjet as a backup?). It's not a huge deal, but standing there waiting for printouts does waste a little T&S time sometimes.

My gut say one of the 2000W quiet Honda generators would be perfect. At most the 3000W one should be fine, though the cost on either of those is a lot more than your run-of-the mill 5000W generator. I wanted a 2000W but had to settle for the 1000W one back when I had to have one right that minute and I love it. I'm not sure how much regular duty the little 1/2000W ones are rated for, though, and I know SCCA uses one of the bigger 3000W ones and has had it for several years now. Stlil pretty dang quiet.


--Donnie

Can we install an awning at the same time as the generator?

Shawn

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OK so I'm back in. Now which tire should I buy??

HOLY CRAP!!!!!! Shawn is in the house!!!!!!!!

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Todd Breakey
STS 42 - 1992 Sunburst Miata
Dammit!
"You souldn't play leap frog with a porcupine. You might get hurt." - Eliza

Can we paint the bus Yellow too?

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2003 F-250
2004 MINI Cooper S
1993 Bovine Beater
1988 325is

The early bird may get the worm, but the second mouse gets the cheese.

I can't help on the bus issue, but I just bought a 2000W digital inverter sine wave generator for our trailer off ebay for 385.00 Buy it now price. It weighs just over 60# and is the size of an overnight bag has built in carrying handle. Runs for 7.5 hrs on 1.8gal of gas. Puts out clean 12V suitable for electronic equipment as well as 120V AC. VERY quiet, 58db @ 7m. Email me for seller link if interested.

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SPIN or WIN!
there's no glory for going slow.

I should mention that on Sunday we found the *real* source of the power problems.

The + battery clamp on the main bus batteries (on the tray under the bus) had cracked due to corrosion, and this is the terminal that the bus accessory battery is connected to. The bolt holding the accessory battery cable to that terminal had also corroded and come loose due to the cracked battery clamp. It was causing enough of a volt drop that the accessory battery was only seeing like 8V under load (and was probably not even being charged). When we had tested the battery last week, it was with no load (open circuit) and it looked healthy at 12+V. Note to self: Always test under load from now on.

I'm surprised that any of the 3 batteries were charging at all -- the bad clamp created a really high resistance, so much so that it was so warm I couldn't touch the cable while the PA and timing gear was only pulling 5-10 amps.

So on Sunday I replaced the bad battery cable, lubed everything, checked the new connections, and sealed stuff up. Should be good for a number of years now. Accessory battery is again seeing 14+ volts when the bus us running, and there is no voltage drop under load. I call it cured.

Back when we first got the bus we replaced one of those clamps but reused the one that just failed. Should have just done them both at that time.

_________________
Mike Whitney
whit32@gmail.com, 919-454-5445
V10, V8, V8t, I6, I6, V6, F4t, I4, I4, I4, I4, I2, 1, 1

anti-generator conspiracy if you ask me. did notice we had a pop-up in front of the bus on sunday. huh. whooda thunk.

Carl and I grabbed it for the school. It lives in the bus. I believe it was purchased, secondhand, after its use during the reading of the Gettysburg address.

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RedLanternRacing, builders of the fastest cars in last place.
Success is not an option.
1981 Scirocco, "Vera"