smkettner
Southern California
Senior Member
Joined: 03/21/2005
View Profile
 Offline
|
If the park is supplying 100 volts at 30 amps they are only supplying 3000 watts and not the expected 3600.
2001 F150 SuperCrew 5.4 Lariat Offroad 4x4 Tow Package 4.10 Truetrac
2006 Keystone Springdale 249FWBHLS
12K SuperGlide, KGE3000Ti 2.3kw rated 2.6kw max
Frank's voltage booster, Prosine 1800 powered by 4 GC2 batteries
|
larry cad
Cindy stop it! U R driving me nuts!!!
Senior Member
Joined: 05/23/2004
View Profile
Offline
|
I agree with MELM, the net effect of the AF will be different depending on whether you consider a resistive device, such as a refrigerator heater, or an inductive device, such as an air conditioner compressor motor. In the case of the refrigerator, the use of the AF will cause a higher amp draw from the post, while in the case of the A/C compressor, the use of an AF will cause a lower amp draw. In warm weather, both devices will be running with the plusses and the minuses just about cancelling out. There will be a small amount of extra power consumption in the AF itself which will have to be paid for by the CG. Low voltage will not cause a problem with the heaters in the frig. Low voltage can cause failure of an A/C compressor. JMHO!!!
Sometimes I wonder, "Why is that frisbee getting bigger?"...and then it hits me!!!!
|
teb1272
Memphis
Senior Member
Joined: 12/14/2006
View Profile
Offline
|
I have a question about this-does a 30 amp circuit breaker trip at approximately 30 amps if the voltage is down to 105 just as it was designed to do at 125 volts? If so, you get 3750 watts (or VA) of power at 125 volts, but only 3150 watts at 105 volts. If not, you should be able to pull about 35+ amps at 105 volts. I realize the things aren't that precise anyway, so it probably makes no real difference, but I doubt that the minor difference arising from transforming your voltage up with an autoformer does either.
|
larry cad
Cindy stop it! U R driving me nuts!!!
Senior Member
Joined: 05/23/2004
View Profile
Offline
|
teb, recommended load in amps from any circuit breaker is no greater than 80% of the breaker rating. For a 30 amp breaker that would be 24 amps continuous load. Yes, 30 amps will eventually trip a 30 amp breaker. 31 amps will trip is sooner and 32 amps even quicker. Circuit breakers have what are known as "time/current" curves. The higher the current, the quicker the breaker will trip when operated at or above rated breaker current. Your comment about available wattage with lower than rated voltage is also correct. Available watts is determined by AMPS * VOLTS.
|
teb1272
Memphis
Senior Member
Joined: 12/14/2006
View Profile
Offline
|
I think you answered my question, but I want to make sure I understand. The CB functions then based on amperage, not power? 30 amps at 105 volts will trip it as fast as 30 amps at 125 volts?
|
|
|
mike4947
N. Syracuse, NY
Moderator
Joined: 08/26/2002
View Profile
Offline
|
I'll never be without one again as I lost an air conditioner to low voltage; and I couldn't care less if it "hurts the park". It's their responsibility to provide adequate voltage and if they scrimp and set up the park for "average usage" rather than peak that's their fault, not mine.
blog.rv.net Your daily guide to the Open Road
Subscribe to the daily digest
Want to sell some of your gear? -
Free Classified Listings on RV.Net
They say you learn by your mistakes, in that case I must be a genius.
|
bdpreece
Woodburn Oregon
Senior Member
Joined: 05/27/2004
View Profile
Offline
|
I have a question regarding 50 amp autoformers. What happens if I have a 50 amp autoformer hard wired in but I am plugged into a 30 amp circuit using a converter plug?
Brian & Loretta
Chance (Golden Retriever)
2004 National Tropi-Cal T396
2005 Suzuki XL-7 toad
We moved!! No more nasty neighbors, no more rotten parking. I am saving this picture just to remind myself how bad it was.
|
billyboy
md
Senior Member
Joined: 12/29/2001
View Profile
|
darn it, if they have the gall to charge you extra for an air conditioner use, then they should have the correct amperage supply. plain and simple
Remember: "Its Not The deal You Got, Its The Deal You Think You Got"
'08 Windsport 33 followed by 2000 Saturn
|
wa8yxm
Wherever I happen to park
Senior Member
Joined: 07/04/2006
View Profile
Offline
|
teb1272 wrote:I think you answered my question, but I want to make sure I understand. The CB functions then based on amperage, not power? 30 amps at 105 volts will trip it as fast as 30 amps at 125 volts?
30 amps is 30 amps, don't matter if it's 12 volts, 120 volts 240 volts or 2000 volts 30 amps is 30 amps.. Though a breaker designed for 120/240 volt service likely won't break 2000 volts (that's another function) it will break 12 volts.
30 amps is 30 amps. power, watts, and so long as you do not exceed the design voltage of the device voltage do not matter
Where power, and confusion come in is that when the autoformer increases voltage, then power in = power out(Plus a bit) so if the output of the autoformer is 20amps at 120 volts, and the input is 100 volts, then the input current is around 24 amps (Figure 25 to be safe)
you can not draw more amps than the park breaker's rating.
The delivery to your rig will be LESS than the park breaker rating when the transformer kicks in.
Very confusing I know.. but it is really very simple
|
Navychop
Fairfax, VA, US
Senior Member
Joined: 08/03/2003
View Profile
Offline
|
bdpreece wrote:I have a question regarding 50 amp autoformers. What happens if I have a 50 amp autoformer hard wired in but I am plugged into a 30 amp circuit using a converter plug?
It will work just fine. That will be the situation with me. I currently use an external 30 amp autoformer, left over from my previous trailer, using an adapter for my 50 amp rig. That also works fine. The campground where I store & do most camping (we own our sites) only provides 30 amps. I want to move that autoformer inside, and have it work when we camp at places where we can get 50 amps.
- - - -
Resistive loads will use more power as the voltage goes up. But they will also do their job quicker and shut down quicker. Think hot water heater.
I simply will not be without an autoformer again. I love where I camp, and they've made improvements to the power, but the volts fall way too low, especially during events such as the Fourth of July. And I've heard of too many a/c units being killed off by low voltage. I monitor the voltage continuously, and that autoformer kicks in a lot..
2004.5 Dodge 3500 Laramie Quad LB SRW CTD 48RE 4.10 4x4
97 30' Coachmen Royal TT traded in April '08 on a
2008 Keystone Challenger 35CKQ fifth wheel
Air Safe 25K air hitch
Kipor 3500Ti (avoid- no support)
|
|
|
