Shuttle Bus Electrical System Wiring Design

[Bodhisava]

Hello,

New to bus life here. I have a 23' (15 passenger) Turtle Top shuttle bus under conversion. My 1400sq. ft. brick and mortar home electric usage is about 43kw/day. I don't think we will consume that much power living in the bus but I am planning for the worse.

The bus will have a 10 cu. ft. house fridge, a 9000 btu mini split, a LG 7kg cloth washer, on demand water heater, 2000w induction cook top, a hairdryer, a mini air fryer, a coffer maker, a toaster and a lap top that use AC current.

On DC side will be 2 vent fans for human, 1 mini vent fan for cat litters, 2 water pumps, 1 macerator toilet pump, LED lighting and 2 cell phone chargers.

AC, Cloth washer, induction cooktop will have their own breaker.
Lap top and hair dryer on same breaker; mini fryer and coffee maker on same breaker; toaster and water heater on same breaker.

Washer is used occasionally early in the morning or late at night to prevent clashing with AC.

Cooktop is for rainy days. We usually use a gas camping stove.

House battery bank:
6x GC2 , 6 Volt, 210Ah, Interstate golf cart battery from Costco
GoWISE Power 3000W Pure Sine Wave Power Inverter

Charging system will be:
1000W solar panels from Harbor Freight
200 amp alternator with Renogy 40A DC to DC Battery Charger

Shore power:
Progressive Dynamics 75 AMP RV Converter PD4575V
Predator 3500W generator


The attached wiring diagrams are what I plan to do.

Need all the advice and info I can get.

Thanks.

Kin

[Rucker]

Difficult to look at the diagrams sideways-yeah, I know, getting the pictures oriented correctly is a bear.

Some of this may already be known to you, but hopefully there's a nugget or two in here that helps.

1. Might be good to specify wire sizes so we can take a look at those. They should be sized to the device amperage draw and distance from power or junction source. Fusing should be based on the size of the wire, and as close to the source as possible, the device fusing should be based on the device, and as close to the device as possible. Fuse the positive lead, and make sure the ground wire is the same size as the positive wire. Estimate lengths, you can always adjust them and the wire size when you get ready to install.

2. Why not LiFePo? Those golf cart batteries are rated for charge/discharge cycles in the low hundreds. You're paying $750 or so for at best 300 amp hours of juice, and I think for another $250-$350 you can get the equivalent capacity in a LiFePo system with 5-10x the charge/discharge life.

3. Is your shore power battery charger on the third diagram the same as the Progressive Dynamics device?

4. My research on DC-DC charge controllers led me to pick the 20A device instead of the 40A device, for the following reasons:

• The alternator cools itself by running at high rpms (highway speeds). There's no easy way to control the Renogy DCDC charge controller. If you wire it as they recommend, when you start the rig, it's charging and drawing whatever juice the batteries need. You'll need max charging on hot days, when you might be sitting in heavy traffic at idle. Less draw is preferable, especially if you're running the second AC system-assuming you kept it.

• If you have a chassis battery bank (2 batteries for the vehicle) the second battery is probably already on a voltage regulator, typically a 15A device. Yours may vary, but adding a 40A DCDC means as soon as you start the rig, if batteries are low, you'll add almost 50A strain on the alternator. Consider at a minimum adding a control line switch so you can turn the charge controller on only when you're on the highway, or under speed.

• My thinking: 20A is plenty of juice if you are driving any distance with the rig, and poses less risk of burning out the alternator prematurely. In your configuration, you can recharge them completely in 15 hrs (assuming 50% depletion of 600A and 20A recharge rate). This is supplemented by youra solar system, and presumably will plug in to shore power at some locations.

5. Your inverter appears to be feeding the GoPower transfer switch. This means your batteries will feed the inverter, which will feed the PD RV Converter, which will in turn charge your batteries. Not sure you want it this way unless you put in a switch on the inverter, which defeats the whole point of an automatic transfer switch.

The PD RV output is (I assume) both 110 AC and 12VDC? If I'm correct, you might want to detail that on the diagram.

I split the shore power in a subpanel, one breaker feeding the GoPower and another for straight shore power juice for a couple of dedicated 'shore power only' outlets.

[Bodhisava]

Hello Rucker,

Thanks for the quick answer. The diagrams were originally horizontal. This is my first upload in this forum. Don't know why and how they turn side way after upload.

1. Once we decide on the appliance, will have more accurate load and usage data. Got all your advice down and will carefully study them before the install. I have a friend who owns a recycling yard so wiring supplies should not be a problem.

2. Since I am new to bus life. If I screw up on maintaining the batteries, it wouldn't cost as much. Also, I am more comfortable working with and maintaining LA batteries but I am also considering AGMs. When this round of batteries die, I would have learn more and be comfortable with lithium batteries.

3. Shore power converter/charger is Progressive Dynamics 75 AMP RV Converter PD4575V. It has AC and DC outputs.

4. I want to separate the bus's original electrical system and the house/leisure electrical system so if the bus has a problem, I can spend a few days living in it and work on it on site. If the house/leisure system crashes, I can still drive the bus to get the parts to fix it.
I have already given away the wheel chair lift. I am replacing the original rear AC and heater with a new mini split so the 200 amp alternator is only charging the starter battery and running the front AC fan. My bus has a dual battery tray but only one battery was installed by the seller. The original external voltage regulator and alternator went bad together. I by passed the regulator and put in a new alternator with internal voltage regulator. I have a E-150 cargo van and I am still trying to figure out the wiring
difference between the Turtle Top (E-450) and the cargo van (E-150). I live in Florida so 20A battery charger is a safer choice. Thanks.

5. My idea was when hooking up to shore power, the surge protector will act as a safe guard to low voltage or faulty wiring. If everything is OK, the power will go to the 8 circuits, breaker/load panel as a second safety check. Then one circuit will go to the automatic transfer switch. One circuit will supply power to outlets on exterior frame for welding and other heavy usage. The GoPower automatic transfer switch supposedly will disconnect the inverter from the battery system and let the PD converter charges the battery and supply the AC and DC power to the house. I was using their wiring suggestion from GoPower to draw the diagram. Will test the system before I install it on the bus.

I really appreciate you take the time to check out with my wiring design. If you have more advice or comments, please let me know.

Thanks.


Kin

[Rucker]

Originally Posted by Bodhisava

Hello Rucker,


5. My idea was when hooking up to shore power, the surge protector will act as a safe guard to low voltage or faulty wiring. If everything is OK, the power will go to the 8 circuits, breaker/load panel as a second safety check. Then one circuit will go to the automatic transfer switch. One circuit will supply power to outlets on exterior frame for welding and other heavy usage. The GoPower automatic transfer switch supposedly will disconnect the inverter from the battery system and let the PD converter charges the battery and supply the AC and DC power to the house. I was using their wiring suggestion from GoPower to draw the diagram. Will test the system before I install it on the bus.



Kin

All good, seems like you're thinking it through. Regarding the GoPower layout I looked at the manual and it does look like the inverter can be wired so it doesn't conflict...still, I'd have to do a little more research (and experimenting) before I'd flip on the fifty amp breaker....

[Bodhisava]

Thanks.

I am go to see where I can put the power center for easy wiring and access.

[Rucker]

Originally Posted by Bodhisava

Hello Rucker,

I live in Florida so 20A battery charger is a safer choice. Thanks.

Kin

BTW if you figure out how to turn the DCDC charger on and off automatically according to engine RPM let me know.

[Rucker]

Originally Posted by Bodhisava

Hello Rucker,



4. I want to separate the bus's original electrical system and the house/leisure electrical system so if the bus has a problem, I can spend a few days living in it and work on it on site. If the house/leisure system crashes, I can still drive the bus to get the parts to fix it.


Kin

Totally agreed. My Chassis system is not connected to the House system other than the DC to DC charger.

[Bodhisava]

May be using a "engine rev limiter with buzzer"? Instead of hooking up to a buzzer, use a relay so when the set RPM is reached, it pass current to a relay that closes the contact to D+ wire for the DC-DC charger.

[Rucker]

Originally Posted by Bodhisava

May be using a "engine rev limiter with buzzer"? Instead of hooking up to a buzzer, use a relay so when the set RPM is reached, it pass current to a relay that closes the contact to D+ wire for the DC-DC charger.

Thank you! I've been looking for something like this for a month with no success!

[Bodhisava]

Glad I can help.

[Ndrober]

A surge suppressor will not protect you from all issue with shore power. I found this out the hard way on my house and needed to replace half the electronics in my house. Some of the ones that plug in line are a combination.

A surge suppressor only protects from short spikes in the voltage. This is great for suppressing lighting in the surrounding area.

You can also have long duration high voltages ( 5 mins is enough to destroy all your electronics) a surge suppressor will not help this. This can happen when you plug into a bad circuit at a campground. This is what destroyed my house when the power company had trouble getting the voltage right after a storm. There are protection relays that can disconnect your shore power if it gets off. This is 240 volt module but they make a 120 volt one too.

https://smile.amazon.com/dp/B097BQHB...VCJ3VZQMDKR7ZX

I also bought a bunch of cheap volt meters and permanently wired them into my bus. I have been on the road two months and seen some odd 180 volt connection a couple times. I setup my rig for 50 amp. (240 volts) but both time I had odd readings on the 50 amp I was able to plug into then 30 amp without issues.

[Bodhisava]

Thanks for the info. I will definitely put one in the set up.