Home » Public Forums » GMCnet » DC only Fridge Options
| DC only Fridge Options [message #296751] |
Sat, 05 March 2016 16:53  |
dr.diesel
Messages: 85
Registered: April 2015
Location: The Haute, Indiana
Karma: 0
|
Member |
|
|
All of the search results were pretty old, any new thoughts on the DC only Nova Kool RFU9000? From what I found it fits the original opening, DC only, top quality Danfoss compressor, no rear venting required.
Any personal experience, any newer stuff worth consideration?
http://www.suremarineservice.com/RFU9000ACDC.aspx
77 Kingsley
|
|
|
|
|
|
|
|
| Re: [GMCnet] DC only Fridge Options [message #296771 is a reply to message #296751] |
Sat, 05 March 2016 22:09  |
Dolph Santorine
Messages: 1236
Registered: April 2011
Location: Wheeling, WV
Karma: -41
|
Senior Member |
|
|
Andy
I'm running a GE mains unit on my Xantrex. $180 fridge. Runs three to four days on 4 T-105 batts.
Dolph Santorine
DE N8JPC
Wheeling, West Virginia
1977 ex-Palm Beach TZE167V100820
1-ton, Sullybuilt Bags, Reaction Arms, 3.70 LSD, Manny Transmission, EV-6010,
> On Mar 5, 2016, at 5:53 PM, Andy wrote:
>
> All of the search results were pretty old, any new thoughts on the DC only Nova Kool RFU9000? From what I found it fits the original opening, DC
> only, top quality Danfoss compressor, no rear venting required.
>
> Any personal experience, any newer stuff worth consideration?
>
> http://www.suremarineservice.com/RFU9000ACDC.aspx
>
>
> --
> 77 Kingsley
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
|
|
|
|
|
|
| Re: DC only Fridge Options [message #296799 is a reply to message #296751] |
Sun, 06 March 2016 09:22 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
|
Senior Member |
|
|
I guess this is a mechanical compressor type. Remember you loose efficiency everytime you convert energy delivery formats. DC would be my last choice. On the 3 ways it's propane, 120V, and DC last in terms of efficiency.
John Lebetski
Woodstock, IL
77 Eleganza II
|
|
|
|
| Re: DC only Fridge Options [message #296800 is a reply to message #296797] |
Sun, 06 March 2016 09:23 |
dr.diesel
Messages: 85
Registered: April 2015
Location: The Haute, Indiana
Karma: 0
|
Member |
|
|
quadracerx1 wrote on Sun, 06 March 2016 09:55
I think ill have to modify the cabinet slightly to allow for the height of the fridge?
Cut out size is a good question, something I've not found documented yet, but I'm sure I'm just missing it somewhere.
77 Kingsley
|
|
|
|
| Re: DC only Fridge Options [message #296801 is a reply to message #296799] |
Sun, 06 March 2016 09:34 |
dr.diesel
Messages: 85
Registered: April 2015
Location: The Haute, Indiana
Karma: 0
|
Member |
|
|
JohnL455 wrote on Sun, 06 March 2016 10:22DC would be my last choice.
The Danfoss units are natively DC, no conversion, and IIRC I thought some of the most efficient available, but need to refresh that as it's been a couple years since I've researched.
77 Kingsley
|
|
|
|
|
|
| Re: DC only Fridge Options [message #296809 is a reply to message #296751] |
Sun, 06 March 2016 10:21 |
Carl S.
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
|
Senior Member |
|
|
dr.diesel wrote on Sat, 05 March 2016 15:53All of the search results were pretty old, any new thoughts on the DC only Nova Kool RFU9000? From what I found it fits the original opening, DC only, top quality Danfoss compressor, no rear venting required.
Any personal experience, any newer stuff worth consideration?
http://www.suremarineservice.com/RFU9000ACDC.aspx
It looks like a good fridge, but at 5.2 amps running (at 12v according to their spec sheet) don't expect to do much dry camping unless you have a large battery bank and lots of solar.
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
|
|
|
|
| Re: DC only Fridge Options [message #296816 is a reply to message #296751] |
Sun, 06 March 2016 11:50 |
 |
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
|
Senior Member |
|
|
We have been running this way for about five years - since the Nocold gave out on me. (I do miss it, but replacement in kind would cost a convention or two.)
The first try was a Frigidaire single door dorm thing that did not have a real freezer and was a real power hog. I had to add a control and fans to the reefer space because modern reefers use the sides and convection for cooling. That unit was too tight in the space to do that right. We ran it on a 50$ HF modified square wave inverter. (750/1500peak MSW) The pump ran a little hot, but when I compared that to shore power, it was no big change. But, the unit itself still sucked power and didn't make ice very well. (The Nocold was better while it worked.)
I got tired of it so we shopped again and found a newer Frigidaire that was much better on power, but a bit smaller on CUFT. Mary bought off on that because it had a separate freezer and the doors could be set the right way. (I Craig's listed the other out and did OK.)
It did use less power, but I still could not keep the house bank up. I had recently installed a real battery monitor. That was when I found out that I could not get power back into the house bank because of line looses from the PD9145w/cw to the house bank on the OE cable. The best it would ever do was a little less than 30. This makes it tough when you need to put 100+ back in the bank. (When you loose 0.6V and you only have 14.4, you take a beating.) So, now we have a 9260 and short heavy copper to the house bank.
Why the 9260 when what I had would have probably done as well if I just moved it?
Simple... The ONLY place (this is 23 - remember?) that I could put the converter in protected space was at the passengers feet. The 9145 is an inch taller than the 9260 and that inch would have made the navigator's table not fit where it needs to be.
We like the new arrangement. The replacement reefers were both about 6" shorter than the Nocold, so I made a nice drawer to go underneath and both give the galley more storage and make the reefer a better height. That was a two column win.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
|
|
|
|
| Re: DC only Fridge Options [message #296817 is a reply to message #296751] |
Sun, 06 March 2016 12:17 |
 |
RF_Burns
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
|
Senior Member |
|
|
Steve (quadracerX1)
The Avanti fridge is what I have and you can see my installation at the link below:
http://www.gmcmhphotos.com/photos/g6634-all-electric-fridge-by-avanti.html
As for the inverter, 3kw is overkill as far as running the fridge. You don't want to run alot of 120Vac equipment from your battery. 3kw at 12 volts works out to about 250 Amps at 12vdc, however at 80% efficiency = 312 amps. Even though you may have 100Amp/hr batteries, that rating is generally at a 20C rate, which means 100a/hr / 20 = 5amps will last 20 hours. At ~312 amps you think you will have 100/312 = ~19 minutes, BUT at high discharge rates the battery capacity goes way down to more like less than 10 minutes Now you don't want to discharge below 50% too many times, so now you are down to less than 5 minutes. BUT the inverter needs the input voltage to stay above 11V or so and you have losses in the wire, plus at 300 amps you are going to lose about 0.5 volts across the fuse. So I'm guessing with new fully charged batteries at 3kw, the inverter will likely start to complain about low voltage likely withing 2 minutes and shut down due to low voltage within a minute of that. So I'm just saying, save your $ and buy a smaller inverter as running high current 120V appliances is not really practical.
Just my finger counting calculations here.
I used a 1500 watt pure sine wave inverter. The refrigerator takes about 600watts for a second or so while starting so I have lots of overhead for that. Plus I could run the microwave (800 watts) for a couple of minutes in a pinch.
You will want to mount the inverter as close to the battery bank as possible to minimize voltage loss in the cable. I have about 6 ft of #4 cable and when the fridge starts, I see a loss of about 1 volt of which half is across the 200 amp fuse. I need to move it closer, not much can be done about the loses across the fuse and a breaker will be slightly higher in my experience.
Voltage losses in the wiring at 120V is only 10% of what it is at 12volts.
Just what I did.
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
|
|
|
|
| Re: [GMCnet] DC only Fridge Options [message #296819 is a reply to message #296817] |
Sun, 06 March 2016 12:26 |
Dolph Santorine
Messages: 1236
Registered: April 2011
Location: Wheeling, WV
Karma: -41
|
Senior Member |
|
|
I use a slightly different child lock on my installation:
http://www.fao.com/product/index.jsp?productId=3749223
And a smaller fridge, but it works just fine - and based on the cost alone, if I fail one out every two years, I’m still ahead.
Dolph
DE N8JPC
Wheeling, West Virginia
1977 26’ ex-PalmBeach
1-Ton, Sullybilt Bags, Reaction Arms, 3.70 LSD, Manny Transmission, EV-6010
“The Aluminum and Fiberglass Mistress"
> On Mar 6, 2016, at 1:17 PM, Bruce Hislop wrote:
>
> Steve (quadracerX1)
> The Avanti fridge is what I have and you can see my installation at the link below:
> http://www.gmcmhphotos.com/photos/g6634-all-electric-fridge-by-avanti.html
>
> As for the inverter, 3kw is overkill as far as running the fridge. You don't want to run alot of 120Vac equipment from your battery. 3kw at 12 volts
> works out to about 250 Amps at 12vdc, however at 80% efficiency = 312 amps. Even though you may have 100Amp/hr batteries, that rating is generally at
> a 20C rate, which means 100a/hr / 20 = 5amps will last 20 hours. At ~312 amps you think you will have 100/312 = ~19 minutes, BUT at high discharge
> rates the battery capacity goes way down to more like less than 10 minutes Now you don't want to discharge below 50% too many times, so now you are
> down to less than 5 minutes. BUT the inverter needs the input voltage to stay above 11V or so and you have losses in the wire, plus at 300 amps you
> are going to lose about 0.5 volts across the fuse. So I'm guessing with new fully charged batteries at 3kw, the inverter will likely start to
> complain about low voltage likely withing 2 minutes and shut down due to low voltage within a minute of that. So I'm just saying, save your $ and buy
> a smaller inverter as running high current 120V appliances is not really practical.
>
> Just my finger counting calculations here.
>
> I used a 1500 watt pure sine wave inverter. The refrigerator takes about 600watts for a second or so while starting so I have lots of overhead for
> that. Plus I could run the microwave (800 watts) for a couple of minutes in a pinch.
>
> You will want to mount the inverter as close to the battery bank as possible to minimize voltage loss in the cable. I have about 6 ft of #4 cable and
> when the fridge starts, I see a loss of about 1 volt of which half is across the 200 amp fuse. I need to move it closer, not much can be done about
> the loses across the fuse and a breaker will be slightly higher in my experience.
>
> Voltage losses in the wiring at 120V is only 10% of what it is at 12volts.
>
> Just what I did.
>
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
> Hubler 1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
|
|
| Re: DC only Fridge Options [message #296820 is a reply to message #296817] |
Sun, 06 March 2016 12:30 |
 |
Richard RV
Messages: 631
Registered: July 2012
Location: Full-timer for 12 years, ...
Karma: -17
|
Senior Member |
|
|
That's interesting, Bruce. I didn't know that there were losses across a fuse. Is that pretty much a linear function with rated fuse amperage?
Richard
'77 Birchaven TZE...777;
'76 Palm Beach under construction;
‘76 Edgemont waiting its turn
|
|
|
|
|
|
|
|
| Re: [GMCnet] DC only Fridge Options [message #296828 is a reply to message #296821] |
Sun, 06 March 2016 12:46 |
k2gkk
Messages: 4452
Registered: November 2009
Karma: -8
|
Senior Member |
|
|
I have a Vitrifrigo (Italian made) DC fridge in the garage that I removed
from my Carver boat when the boat was totaled in a marina collapse.
I will probably install it in my GMC later, assuming I ever get the 455
motor repaired or replaced.
It is actually DC only, with auto-select between 12 and 24 VDC with a
Danfoss compressor. When on 120 VAC "shore" power, a separate power
supply provides 24 VDC to the fridge. When on 12 VDC house battery
power, the compressor runs on that. It's a 2-door model with a top
freezer compartment and it does quite well and is quite well insulated.
It also is unlikely to set the coach on fire! ! ! !
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~~ ~ D C "Mac" Macdonald ~ ~~
~ ~ Amateur Radio - K2GKK ~ ~
~ ~ Since 30 November '53 ~ ~
~ ~ USAF and FAA, Retired ~ ~
~ Member GMCMI and Classics ~
~ ~ ~ Oklahoma City, OK ~ ~ ~
~~ ~ ~ "The Money Pit" ~ ~ ~~
~ ~ ~ ~ TZE166V101966 ~ ~ ~ ~
~ ~ ~ '76 ex-Palm Beach ~ ~ ~
~~ k2gkk + hotmail dot com ~~
~ www.gmcmhphotos.com/okclb ~
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
______________
|[ ]~~~[][ ][]\
"--OO--[]---O-"
> Date: Sun, 6 Mar 2016 11:30:37 -0700
> To: gmclist@list.gmcnet.org
> From: bruce@perthcomm.com
> Subject: Re: [GMCnet] DC only Fridge Options
>
> One thing I added last summer was a Power On Delay Timer.
>
> We changed refer power from mains voltage to the inverter or back manually so it doesn't run on the inverter when the coach is plugged in. More often
> than not the fridge was running when I changed power and I forgot to check it. So when it powers back up, the compressor can't start due to the
> compression load and therefor is stalled and the overload kicks out. This is hard on the compressor and the overload relay. The Power On Delay Timer
> delays power to the compressor for 10 minutes after power is applied to the fridge. This allows time for the refrigerant pressures to equalize and
> then allow the compressor to start under no load.
>
> It was just a multi-function relay I had kicking around which had On-Delay function.
>
> JWID
>
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
> Hubler 1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
|
|
|
|
|
|
Goto Forum:
Current Time: Thu Oct 10 17:30:55 CDT 2024
Total time taken to generate the page: 0.09654 seconds
|
GMCforum
Search
Help
Register
Login
Home
