| Author |
Message |
Brian Brown (Fishbowlbrian)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 10, 2005 - 5:00 pm: | |
Hi All:
Thanks for bearing with me as I broaden my electrical know-how via you guys’ hard-earned knowledge and experience.
True to form, I made up a page of eye candy showing my electrical charging parts and pieces here: http://www.browncowpro.com/bus/4106/elec/charging.htm
Hopefully, the specs of each item are clear enough. The bottom four items have been recently acquired via the ePlace, and I’d like to use them in my coach... if they are appropriate and make sense, electrically-speaking. The alt. regulator can be bypassed with the Xantrex three-stage or left alone and I sell the Xantrex.
All I’m really after for my summer trips (4 weeks of mostly Pole-to-Pole camping)is thus:
- change house bank (not yet purchased) and coach bank while underway
- run off house bank while parked overnight at rest stops, Cabellas, WalMart, etc.
- prevent draw-down of start batts while parked
- run 12v stuff while plugged-in (there are two 30A converters inside)
My 120v needs can be met by the genset or PP. I’m currently saving my pennies for a nice RV-style inverter/ charger, but will have to wait til after I sell/part out the old Fishbowl to buy it.
My biggest question is how much max. current flows through my system when starting the 8v71. I’m not sure if the switch is big enough for it, and I can certainly eliminate it (it was "thrown in" along with the voltmeter panel when I bought the Schottky isolator). Speaking of the isolator, I don’t want to damage it with too much starting current, either (if starting current even flows through it).
Otherwise, I’d be most appreciative of any and all advice on the direction I’m heading with this system.
Sorry for my ineptitude in these matters. And thanks, as always,
Brian Brown
PD4106-1175
Longmont, CO USA |
Sean Welsh (Sean)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 10, 2005 - 7:55 pm: | |
Brian,
The isolator goes between the alternator and everything else. The starter connects directly to the start batteries. So you should not have any concerns regarding that aspect.
I'd keep the three-stage regulator. Just bear in mind that wiring the regulator, alternator, isolator, and batteries must be done very carefully, to avoid accidentally creating a current path from one side of the isolator to the other through the regulator.
The other comment I would make is that 130a @ 14v is not a lot of power. You may need to add more charge capacity at some point in order to get the level of house battery charging you want going down the road.
HTH,
-Sean |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 11, 2005 - 2:26 am: | |
Brian, when we start our 8V71, it draws about 400 amps when cold. If battery voltage is not too low, you can run the starting current through your battery monitor's shunt if it is rated for 500 amps per leg.
A good rule of thumb for inverter use is to multiply AC current by 11 to get the 12 volt input current. You'll seldom do much better than that.
One problem about running AC inductive loads on the inverter is that the inverter is rated in volt amps, not watts. Running a lightly loaded AC motor will draw most of it's full load current, leaving little margin for other AC loads.
What happens as you add load to an AC motor is that the current becomes more in step with the voltage, increasing the true power used. But the windings produce most of the heat on a light load that they produce on a full load because of the large current draw.
This is why you don't want to run such loads on the inverter very near it's capacity; big inverter capacity reduces this problem.
We have an old 32 volt consta-volt charger that draws over 20 amps with no load, but it only increases a few amps when putting out full power. This is an example of something that can not be run on an inverter because it draws too much of the rated output.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher |
Ray Lala (Rayshound)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 11, 2005 - 11:48 am: | |
Would the xantrex 3-stage regulator work on the 24v 50n alt/ I would like to get a better regulator for my bus alt the 270 amp belt driven.
I am using this alt do feed a 3600 watt trace dr series inverter. Thanks Ray |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 11, 2005 - 11:11 pm: | |
Ray, in recent times, the finals in those regulators have been rated for 10 amps in the 12 volt models and they draw about 8.
I think that 24 volt regulators are likely available, as well, and if they're current generation, they will be able to monitor both battery and alternator temperature.
I don't think that you need the monitor for the oil cooled units because they were designed to work heavily loaded. That's not the case with a lot of automotive alternators.
Xantrex likes to get a hell of a price out of theirs. We do a lot of this kind of shopping on eBay and can usually buy for 1/3 to 1/2 of retail.
Do pay close attention to details as it is easy to get stung if you are unwary.
Good luck.
Tom Caffrey PD4106-2576
Suncatcher |
Ray Lala (Rayshound)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 12, 2005 - 4:40 pm: | |
Thanks Tom for the info. I intend to rebuild my 50dn and install on my series 60 to run an inverter. I would rather get a later model 3 stage regulator than reuse the old transistor type that it came with. I see that IBP carries the bearings & coils, diodes etc to go through and see if it needs anything before getting out on the road with it. Thanks again Ray |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 13, 2005 - 4:26 pm: | |
Ray, unless the 50DN has been damaged by something, I would think that about all the preventative maintenance that would be useful would be changing out the bearings.
They're brushless, so there is very little to wear, I would think.
Take care.
Tom Caffrey PD4106-2576
Suncatcher |
Brian Brown (Fishbowlbrian)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 13, 2005 - 6:36 pm: | |
Thanks for the tips, guys!
I've also been reading Sean's replies to RC's isolator questions on a similar thread. I dunno if the electrical side is just overly complex or I'm just overly dense (or both), but it's eye opening, nonetheless.
From what I’m reading, it appears that the biggest issue with using my isolator/regulator combo is that the battery sense can only be drawn from either bank. So, now I’m wondering if I should just set a house side alt., maybe running off of the old A/C PTO and have separate systems altogether.
Decisions, decisions…
Brian Brown |
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