CRD as a residential backup power source

dgeist · **Posted:** Wed May 18, 2011 10:50 am

So, I've been casually looking at residential backup power systems for my house and can't seem to find one that's liquid-cooled, runs on diesel (or CNG would work if the price were right) and doesn't cost $10k. I got to thinking: why not simply have a 120/240v inverter and a NEMA power plug in the driveway or garage and use the CRD as a generation for short durations?

Has anyone done anything like this (in the CRD or other vehicles)? What are the limitations of the CRD's electrical system? I know the alternator can't run my house AC, but can it reasonably drive a 3k-5kW pure-sine inverter?

Dan

flman · **Posted:** Wed May 18, 2011 11:12 am

Could replace the alternator with a generator, along with some diodes for the DC that the Jeep needs. I once owned a used Telephone company utility truck, and it had a generator under the hood, and had AC power at the utility body.

Radman · **Posted:** Wed May 18, 2011 11:15 am

I once saw an article where someone did this with a VW TDI engine. Engine out of car however and set-up as generator specifically. Turbo lubrication may be an issue unless you can get the RPM's up?

Drewd · **Joined:** Mon Feb 06, 2006 12:24 pm **Posts:** 902

Yeah, you would need a way to get rpms up to 1800 rpm and use pulley combo so generator spins at 3600 rpm to obtain 60hz or run it at 3600 rpm like most small 3-5k diesel generators do ;-)

flman · **Posted:** Wed May 18, 2011 12:05 pm

The truck I had, had no alternator, just a Leece Neville generator under the hood, for AC and DC power. The unit was not much bigger then an alternator either.

sota · **Joined:** Fri Aug 07, 2009 7:44 pm **Posts:** 379

since backup power is one of those items I concern myself with constantly (I run an IT consulting biz out of my house, with hosting services. power outages are a Really Bad Thing for business) I would suggest you approach the problem by asking these questions first...
1) how often does the power go out?
2) how critical is it when the power is out? (medical needs? services? or just to keep the fridge cold?)
3) how "idiot proof" do you want to make it?
4) what is your budget?

I'll give you myself as an example...
I have a single gasoline powered 5500w generator, capable of doing 240V 20A, that I use very infrequently (1 to 2 times a year at most) that I connect to 4 circuits in my house... basement/computers, master bedroom, HVAC (not the actual condenser though), and kitchen. Why these circuits? the basement/computer one is obvious, it runs my business. the master bedroom is there just to keep us happy and the alarm clocks working along with the ceiling fan :SOMBRERO:

, HVAC to power up the household ventilation and furnace in the winter, and kitchen to keep the fridge happy. Based on when my long-duration outages happen (winter time) this winds up being the most effective setup for me. The short term ones (less than an hour or so) are mitigated by battery backups on the computer equipment. I considered a whole-house CNG fired generator once, but as you've noticed the cost is prohibitive and isn't needed that much in my area.

dgeist · **Posted:** Wed May 18, 2011 2:05 pm

sota wrote:

since backup power is one of those items I concern myself with constantly (I run an IT consulting biz out of my house, with hosting services. power outages are a Really Bad Thing for business) I would suggest you approach the problem by asking these questions first...
1) how often does the power go out?
2) how critical is it when the power is out? (medical needs? services? or just to keep the fridge cold?)
3) how "idiot proof" do you want to make it?
4) what is your budget?

Answers:
1) probably ~10 times a year for the duration of an hour or less; once in a blue moon for multiple hours
2) medium criticality. I'd like to keep the server rack running (as I host as well) but no-one's paying for it, so I won't cry if I'm off for a little while, but I'd like it to nor reboot for no reason.
3) I'll be the idiot, so it doesn't have to be idiot-proof at all.
4) I'd like to keep it under $500 (above and beyond other electrical upgrades I'm doing).

It would also be nice to retain ability for heating and hot water (blower in the furnace and circuit-board in the water heater). The former has some steep instantaneous load but uses less than a kW continuous. The latter is about as much as a light bulb.

Essentially, I"m looking for if I can do a multiple kw pure-sine inverter that will run off the existing electrical system on the jeep and not kill it.

Dan

ChesterCRD · **Posted:** Wed May 18, 2011 3:14 pm

I'll give you my less than scientific thoughts on it.

Your situation sounds similar to mine and I live in hurricane country...so I have some experience with multi-day power outages.

With a vehicle power source you're limited to the peak output of the alternator, usually around 120 amps at 12 V. At 120 volts you'll get 12 amps max (some losses, so less usually). In addition you'll be running at idle, so even less. This isn't your solution if you have much draw.

I use a Trace 5500 48V inverter (http://www.wholesalesolar.com/products. ... w5548.html) attached to four deep cycle batteries. I have 120 amp-hours of battery at 48V which is enough to run lights, TV, fridge, and some ceiling fans for about 20 hrs. It's nice because it's quiet and the wife doesn't have to do anything with it when I'm not there. The inverter isn't hard wired in, but if it were it would act like a UPS...switching from utility feed to inverter feed in 1/40 of a cycle. It can also manage the generator, but again I don't have it wired that way.

I use a 5500 watt diesel generator (air cooled) to charge the batteries and run the house when they are are charging. I use a T240 transformer from trace to balance the legs and take the 240v to 120v for the inverter, which then passes it through to the load while taking some power to charge the batteries. I can charge them in about 4 hours with this method while running whatever I want int the house except the central AC, dryer, and water heater.

I got the trace equipment off ebay for about $1500 total and I think I bought the generator locally for $700 (used, less than 5 hrs). I'm ok with an air cooled 3600 RPM generator as I don't run it much and will probably never wear it out.

Some other thoughts...if you are really set on a water cooled, heavy duty solution check out utterpower.com. They sell a CD with lots of useful info and will help you hook together a solution that should work well even under continuous (off-grid) use.

bugnout · **Posted:** Wed May 18, 2011 4:51 pm

Why water cooled??

I would go with a propane or natural gas automatic backup generator. About $3000 will get you 14KW of backup power.

During a power emergency, Natural Gas tends to still be available when the lines at the service stations get long (if you can find one with power to run the pumps.) I have an old 5500w generator and a 8 circuit transfer switch, maybe $600 total in my backup power setup, but I only have interuptions once or twice a year so I can't justify the expense. If my power was going out 10 times a year, I'd be making the investment.

I've seen a couple of stand alone generators that used the PTO off a Kubota or other tractor to turn them.

camo · **Posted:** Wed May 18, 2011 5:02 pm

Back on hurricane Ike (2008) we were about 3 weeks without power down here in houston. so what I did i use a 4000w peak- 2000w constant power inverter conected to my ram 1500 and was able to run the refrigerator, one tv, internet modem, couple of lamps, and a couple of fans. so the ram ran it during the night time and a regulated solar panels system ran at day light. It was very successful, but I wish I dont have to use it again :mrgreen:

dgeist · **Posted:** Wed May 18, 2011 5:12 pm

I'm thinking I might be better-served to just install one of these:
http://www.amazon.com/Tripp-Lite-APS3636VR-Inverter-Automatic/dp/B00006HO5G/ref=sr_1_6?ie=UTF8&s=electronics&qid=1305752945&sr=1-6

Provides 3600W continuous of essentially UPS-grade power to anything I want to hard-wire into it... Or get smaller similarly capable units down to 700W, all capable of (nearly) infinite runtime from parallel batteries, with the option to throw-in a NEMA plug and an outdoor genset to recharge things... Perhaps I'll leave the jeep inverter for running the laptop

Dan

sota · **Joined:** Fri Aug 07, 2009 7:44 pm **Posts:** 379

dgeist wrote:

sota wrote:

since backup power is one of those items I concern myself with constantly (I run an IT consulting biz out of my house, with hosting services. power outages are a Really Bad Thing for business) I would suggest you approach the problem by asking these questions first...
1) how often does the power go out?
2) how critical is it when the power is out? (medical needs? services? or just to keep the fridge cold?)
3) how "idiot proof" do you want to make it?
4) what is your budget?

Answers:
1) probably ~10 times a year for the duration of an hour or less; once in a blue moon for multiple hours
2) medium criticality. I'd like to keep the server rack running (as I host as well) but no-one's paying for it, so I won't cry if I'm off for a little while, but I'd like it to nor reboot for no reason.
3) I'll be the idiot, so it doesn't have to be idiot-proof at all.
4) I'd like to keep it under $500 (above and beyond other electrical upgrades I'm doing).

It would also be nice to retain ability for heating and hot water (blower in the furnace and circuit-board in the water heater). The former has some steep instantaneous load but uses less than a kW continuous. The latter is about as much as a light bulb.

Essentially, I"m looking for if I can do a multiple kw pure-sine inverter that will run off the existing electrical system on the jeep and not kill it.

Dan

Would you consider something intelligent like an APC UTS10BI automatic transfer switch, the hardwire addon, the generator start addon, and an appropriate sized generator? that combo with some basic electrical work would run you by my estimates about $1200 to $1500 total. it also won't need to be tied to the jeep in any way. I'd suggest researching the UTS10BI... for not alot of cash (little over $400 lately) you get alot of functionality. I've put a couple in at client sites (auto parts stores) and they love them.

flash7210 · **Posted:** Wed May 18, 2011 8:23 pm

You can build you own gasoline generator using an old lawnmower engine, alternator, battery
and inverter.
See this link:
http://theepicenter.com/tow02077.html

dkenny · **Posted:** Wed May 18, 2011 9:21 pm

if the transfer case/transmission had a PTO it would worth it.
other wise forget..

the Alternator doesn't put out enough amps.
no good place to run enough belts to run another alternator to get enough power..

6000 watts at 120v is 50amp but at 12v its 500amps..just think of the wire size needed..for normal AC its not measures in gauge anymore..4/0 is the largest..but that's not enough..don't misunderstand me I know there are wires larger than 4/0 these aren't measured in a gauge, but the area. sure length is important too..

-dkenny

Greasey Bob · **Joined:** Tue Dec 14, 2010 3:34 am **Posts:** 228

CRD's do not actually like to idle for an hour(s). I have no technical reason but I have left it idle for 1/2 hour and it was not happy. It started smoking and spuddering and just not really running like normal. I purchased a brand new diesel 6000w generator for $550 after taxes about 2 years ago. I have never taken it out of the box. I have been meaning to run my house on it but life gets in the way of projects that are experimental and make lots of noise.

On that sour note after hurricane Wilma I used a small 1500w invertor to turn on the computer at my house and run a few electrical items, it was connected to my Dodge Ram 2500 Turbo diesel that ran on Waste Veg Oil. I left it running for six hours on accident-- no problems.

Sir Sam · **Posted:** Thu May 19, 2011 12:48 am

You need this:

http://www.harborfreight.com/10000-watt ... 45416.html

yakers · **Posted:** Thu May 19, 2011 1:06 am

Greasey Bob wrote:

CRD's do not actually like to idle for an hour(s). .

I asked about long idles a while back and got an OK from the posters here. (Not sure how to search for a thread that old.) I went on for a couple visits to Black Rock Desert NV where I would idle for AC use anywhere from 20 minutes to 2 hours to get through dust storms or peak heat. Also had times when I let it idle long periods for heat. Never had a problem, no stumbles, erratic idle or any other issues.

Sir Sam · **Posted:** Thu May 19, 2011 2:00 am

yakers wrote:

Greasey Bob wrote:

CRD's do not actually like to idle for an hour(s). .

I asked about long idles a while back and got an OK from the posters here. (Not sure how to search for a thread that old.) I went on for a couple visits to Black Rock Desert NV where I would idle for AC use anywhere from 20 minutes to 2 hours to get through dust storms or peak heat. Also had times when I let it idle long periods for heat. Never had a problem, no stumbles, erratic idle or any other issues.

LOL @ "Black Rock Desert" :BANANA:

geordi · **Posted:** Thu May 19, 2011 2:21 am

2 hours is nothing, I have used both my diesels (VW Jetta TDI and the CRD) as portable hotels, idling for up to 8 hours at a stretch. No problems at all. The "you have to have high rpm to prevent leaking turbo" is a complete MYTH.

If the turbo were capable of leaking like that, just driving around and waiting at lights would cause your CRD to lose all its oil between changes.
Quite frankly - modern turbo designs like ours DO NOT need any specific RPM to operate properly. The pressurized inflow of oil creates an almost frictionless condition for the central shaft to spin, and once that pressure is there... The slightest puff of incoming air through either the turbine or compressor WILL CAUSE the center to spin quickly. The turbo is ALWAYS spinning, even at idle.

With regard to the power generator idea, it is one that I support and have investigated myself b/c of my work with the film industry. If there is a way to install a generator head under the hood, I would like to learn more about it!

You don't necessarily need to run the engine at 1800 rpm to make proper power, although the logic is correct. Single-pole generators (the cheapest ones) can ONLY make proper power when spinning at 3600 rpm. I would suspect that Harbor Freight power head to be one of those. Better units are the dual-pole 1800 rpm units... But there are also 4-pole units that will run at 900 rpm.

For the original poster's power project however... Why not look into a complete trailer or skid mounted generator from an equipment auction? 25kW diesel water-cooled Izuzu powered generators from MQ Power and others (fully enclosed units) sell for about $3000 all the time. Look at Ritchie Brothers Auctions for more info, they auction all over the place.

ChesterCRD · **Posted:** Thu May 19, 2011 8:33 am

flash7210 wrote:

You can build you own gasoline generator using an old lawnmower engine, alternator, battery
and inverter.
See this link:
http://theepicenter.com/tow02077.html

I have this kit. I haven't put it together yet, but it looks decent. I've been watching for a 48V alternator that I can afford for it.

CRD as a residential backup power source

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