coffee maker vs inverter
- Thread starter edjahar42
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Ken & Sheila
Site Team
2ga is OK (1.7% voltage drop for 100 amps over 6 feet) for the coffee pot, but I would upgrade the negative to 1/0 to match the positive and provide for less voltage loss. 1/0 is OK for 165 amps with 6 foot cables (1800watts divided by 12 volts time 1.1 for the inverter efficiency factor).
Before working on the inverter I would remove all the connections, clean and replace.
ken'
Before working on the inverter I would remove all the connections, clean and replace.
ken'
TwoTmblwds
Member
- Joined
- Apr 5, 2011
- Posts
- 15
Just an aside,
remember the cables between the batteries need to be as big as the inverter cables. Well maybe not quite because of the short length, but why risk it?
remember the cables between the batteries need to be as big as the inverter cables. Well maybe not quite because of the short length, but why risk it?
Gary RV_Wizard
Site Team
You need to put a voltmeter on the cables near the inverter while the coffee pot is running (however briefly). I'm pretty confident you will see it go below 11.5v, which is the usual inverter cut-off point. If not, then maybe the inverter needs to be replaced.
I would turn off all circuit breakers except for the one for the coffee maker (Probably a 15amp, marked plugs), then try it. An early post ask the question but did not elaborate on making sure there are no other draws. Think about the fridge, water heater etc. These are high wattage loads.
yolo
Well-known member
We just blew out the third Mr Coffee with the automatic clock last night. It was running on the inverter. Went to Wal-Mart today for a new replacement. Hooked it up and ran a pot through with the generator running. When I shut down the generator, I noticed that the pot was smoking. I unplugged it. Then I started the generator again and it was okay. Now will have to make sure that the pot is unplugged when the inverter is running. The fancy electronics couldn't stand the square waves. Everything else on the coach seems to run fine with the square wave 120 volt AC.
Conquest aka Robert
Well-known member
I would try a differant coffe pot try a plain generic one with no bells or whistles.
As a long time sailor who has struggled with Mr Coffees over the years, it's amusing to get into a new game with the same problem. On my smallish sailboat we've gone to a minimalist solution that works well. A 1250 watt inverter with overload capacity from the dreaded AIMS, coupled with a 1000 watt hotpot and a french press. For some reason, the hot pot is a really easy load to run on the little inverter. I wouldnt run it on a low battery but it does well on a fresh battery down to maybe 12.2 volts. Takes it down under 12 volts temporarily, but it boils quickly (whereas mr coffee brews on & on, sucking volts) and then the batts bounce back within .2 volts of the pre-boil condition on my single Group 31. I've used it several times on the same cycle without recharging too. While sailing! I love it!
And you know, these RVs have such a convenient flat top wonderful propane stove that never heels or sloshes on waves, so why not use the tea kettle & french press? (or even a percolator) So easy! (try to use those things at 35 degrees of heel when your cold and WET & have been all night! grr just hand me up a Red Bull!)
Sailboats too have had to develop massive inverter systems to run the Mr Coffee. It all seems out of proportion when you consider it's the only huge load.
And you know, these RVs have such a convenient flat top wonderful propane stove that never heels or sloshes on waves, so why not use the tea kettle & french press? (or even a percolator) So easy! (try to use those things at 35 degrees of heel when your cold and WET & have been all night! grr just hand me up a Red Bull!)
Sailboats too have had to develop massive inverter systems to run the Mr Coffee. It all seems out of proportion when you consider it's the only huge load.
NY_Dutch
Well-known member
When we don't have shorepower, and can't or won't run the generator to make coffee, we just heat up a pan of water on the stove and pour it into the basket of our low cost, no frills, just an on/off switch Mr. Coffee. Works fine...
1joester2
Well-known member
Something else to consider from the inverter side of this...
You have a '94 RV with a 2001 inverter and have owned it for 2 years.
How much did the previous owner use the inverter, and how many times has it tripped before you owned it?
I don't care how well built or installed something is, it will only trip into safety shut-down so many times before the circuitry begins to fail. When it does, it could either trip for no real reason, or fail to trip. Yours appears to be all too willing to shut down. I would contact the manufacturer to see if they might be able to test/repair it or find an electronic repair person with a shop who can diagnose component level failures. Perhaps the manufacturer can refer if they don't care to do the work.
I have repaired a few inverters ranging from dinky 75W units up to the 1500W I am currently using in my rig. If you're lucky, you have a unit failing due to bulging capacitors. Many electronic devices made around the vintage of your inverter had defective capacitors installed during the manufacturing process. These capacitors have a tell-tale sign they are failing since the tops bulge up. Simply replacing them can restore your electronic device to working order. They are usually a cheap component as well, so a decently qualified shop can handle the job IF that applies to your inverter.
If you can easily access the unit and peek into it through the openings for air flow, shine a flashlight into it and see if the top of the electrolytic caps are flat. A quick google search for "bulging capacitors" should return all the help you need identifying them ans determining if they need replaced.
The bad capacitors were used in a very wide assortment of electronics so nothing is exempt from this possibility. Computers, monitors, radios, TV's, ect...
As with anything electric related, make sure the POWER IS OFF and ALL CIRCUITS ARE DEAD before touching anything. Unplug from shore power and make sure the generator is off.
If you are unsure about doing the inspection, just about any electronics technician can do it for you.
Joe
You have a '94 RV with a 2001 inverter and have owned it for 2 years.
How much did the previous owner use the inverter, and how many times has it tripped before you owned it?
I don't care how well built or installed something is, it will only trip into safety shut-down so many times before the circuitry begins to fail. When it does, it could either trip for no real reason, or fail to trip. Yours appears to be all too willing to shut down. I would contact the manufacturer to see if they might be able to test/repair it or find an electronic repair person with a shop who can diagnose component level failures. Perhaps the manufacturer can refer if they don't care to do the work.
I have repaired a few inverters ranging from dinky 75W units up to the 1500W I am currently using in my rig. If you're lucky, you have a unit failing due to bulging capacitors. Many electronic devices made around the vintage of your inverter had defective capacitors installed during the manufacturing process. These capacitors have a tell-tale sign they are failing since the tops bulge up. Simply replacing them can restore your electronic device to working order. They are usually a cheap component as well, so a decently qualified shop can handle the job IF that applies to your inverter.
If you can easily access the unit and peek into it through the openings for air flow, shine a flashlight into it and see if the top of the electrolytic caps are flat. A quick google search for "bulging capacitors" should return all the help you need identifying them ans determining if they need replaced.
The bad capacitors were used in a very wide assortment of electronics so nothing is exempt from this possibility. Computers, monitors, radios, TV's, ect...
As with anything electric related, make sure the POWER IS OFF and ALL CIRCUITS ARE DEAD before touching anything. Unplug from shore power and make sure the generator is off.
If you are unsure about doing the inspection, just about any electronics technician can do it for you.
Joe
BernieD
Well-known member
Every coffee pot I've used in our RV that had a clock stopped working or blew something in it's electronics whenever I tried using it with our modified sine wave inverter. Simple on/off switch coffeemakers work fine. Right now I'm using the Aeropress which just needs heated water which you can get from the stove.
John From Detroit
Well-known member
Re: MR. Coffee on inverter...
Is that an MSW inverter?
I have never torn apart a Mr. Coffee. but there was a poster a while back who claimed that using a Kill-a-watt meter on an inverter, even a true sine ivnerter, would let the magic smoke out of the meter. (By the way, My Kill-a-watt is normally "Stored" in an outlet that is inverter powered, less I need it elsewhere, So far it's retained all it's smoke just fine)
He gave an explanation for why.. It may be that his explanation works better with your coffee pot.
Recommendations: If your inverter is MSW.. You might try a true sine (That's the high price recommendation)
Recommendation 2 (MUCH MUCH Less expensive) Get a "Basic" coffee pot, one without any timer or fancy electronics of any kind, Just an ON/OFF switch.. That's the kind I have.
Is that an MSW inverter?
I have never torn apart a Mr. Coffee. but there was a poster a while back who claimed that using a Kill-a-watt meter on an inverter, even a true sine ivnerter, would let the magic smoke out of the meter. (By the way, My Kill-a-watt is normally "Stored" in an outlet that is inverter powered, less I need it elsewhere, So far it's retained all it's smoke just fine)
He gave an explanation for why.. It may be that his explanation works better with your coffee pot.
Recommendations: If your inverter is MSW.. You might try a true sine (That's the high price recommendation)
Recommendation 2 (MUCH MUCH Less expensive) Get a "Basic" coffee pot, one without any timer or fancy electronics of any kind, Just an ON/OFF switch.. That's the kind I have.
yolo
Well-known member
John From Detroit said:
The inverter is a Dimensions 2kw unit. I have a Kill-a-watt plugged in all of the time also. It is quite happy with the inverter.
I don't think that I will spend the bucks for a true sine wave inverter. This one works on everything else.
So far the replacement coffee pots have been free from Wal-Mart. I just take them back and say that they broke and get a new one. Never thought that it was me breaking them. The new plan is that when I boon dock, which I am right now, to leave the pot unplugged until the generator is started to charge batteries, etc. When we are on shore power I can leave it plugged in. It always rides in a cabinet when moving.
John From Detroit
Well-known member
Thanks for the confirmation on the Kill-a-watt... The problem is there are a couple of ways of siphoning power off to run the electrioncs in the "Fancy" coffee pots.. one of those can be adversly affected by MSW type inverters.. the rest won't care. I suspct that may be what's happening.
A "Standard" coffee pot though, one without the fancy timer, Just an on/off switch/button, is not much more than a thermostat (Bi-metal type) and a resistor, and of course the switch, It works as well on DC as AC and could care less about the wave form.
A "Standard" coffee pot though, one without the fancy timer, Just an on/off switch/button, is not much more than a thermostat (Bi-metal type) and a resistor, and of course the switch, It works as well on DC as AC and could care less about the wave form.
jim and di
Well-known member
Now that is a good idea, Dutch, thanks
Bit Bucket
Member
While your cable size is rated (barely) to handle that load in amps, the voltage drop on that size of load is probably too much for your wire size. All main DC wires (battery interconnect and feed) should be 2/0 for that size inverter even with wires only around 5-6 ft long apiece. One of the things that is different with 12 volt systems is that voltage drop is *critical*. A few volts of drop at 120 vac is one thing, another in a 12 vdc system. My inverter (2800 watt) needs 4/0 cable and no more than aprrox 15 feet TOTAL of wire distance (both cables added together).
In my opinion, your cable size is too small and is allowing too much voltage drop and your inverter is probably shutting down on low voltage as others have stated.
Good luck on finding the problem, happy camping!
In my opinion, your cable size is too small and is allowing too much voltage drop and your inverter is probably shutting down on low voltage as others have stated.
Good luck on finding the problem, happy camping!
