Voltage issue

DBrown · Post by **DBrown** » Wed Dec 28, 2011 6:02 pm

Has anyone else had this problem. When trying to use our Keurig coffee maker running off the generator, the coffee maker will not operate. We seem to not have enough voltage. However, after driving for an hour or more, leaving the engine running, and turning the generater on, it will work. Our coach is a 2008 27 RSB gas. All the other 120 volt appliances work such the microwave, water heater, and electric heater. Any ideas. Thanks

al1florida · Post by **al1florida** » Wed Dec 28, 2011 6:49 pm

More detail about the problem would be very helpful. Running the engine should not have any affect on what the generator does.

When you say "it doesn't have enough voltage", please be more specific.

Did you measure the voltage at the outlet when the coffee maker was trying to work?

Does the coffee maker do this when plugged into all the different outlets or just the one you always use to make the coffee?

Would you describe in more detail what the coffee maker does or doesn't do.

By some chance is the coffee maker a 12V DC (battery) operated coffee maker????

DBrown · Post by **DBrown** » Wed Dec 28, 2011 7:19 pm

Al, thanks for your response. When I say it doesn't have enough voltage, I'm not sure that's the problem. I have not measured the voltage at the outlet. Coffeemaker does the same thing regardless of which outlet you use.
As far as what the coffeemaker does, it doesn't heat up or make coffee. The light comes on, but it doesn't go through the cycle of making coffee. It is a 120 volt coffeemaker. It always works when we are plugged into shore power. I know it doesn't make any sense, but it seems like the coffeemaker is affected by the charge level of the house batteries. Is that possible?
Thanks

al1florida · Post by **al1florida** » Wed Dec 28, 2011 8:17 pm

No, I can't think of any reason why electric output of the generator would be affected by the charge level of the batteries.

I wonder if your coffee maker is very sensitive to frequency (60 cycle) of the AC power. The generator is not very good a staying exactly on 60 cycles. Most devices don't care if the 60 CPS goes up to 68 or down to 55 or so. Also if a heavy load kicks on the cycles can drop quite a ways (down to maybe 30-40 instead of the normal 60) like when the air conditioner starts. It takes a 1/2 second or maybe a second and an half for the generator comes back up to speed after the a/c kicks on.

That doesn't account for why it works after driving for a while.

Is the coffee maker really old? Maybe the power cord wires are mostly broken off inside the insulation, near the plug end, limiting the power, i.e. current to the coffee maker.

Can you borrow a different coffee maker and see if it works OK when yous doesn't?

Do you have a hair dryer or a small electric heater to plug in when the coffee maker doesn't work to see if they work OK. Unplug the coffee maker first so you don't have both trying to work at the same time.

DBrown · Post by **DBrown** » Wed Dec 28, 2011 8:34 pm

Thanks for your thoughts. Actually it's nearly new. I think it may be time to just give up on this coffeepot and go back to a more traditional kind.
Thanks

Mike Jean Bandfield · Post by **Mike Jean Bandfield** » Wed Dec 28, 2011 9:18 pm

You didn't say what the capacity of your generator is. I have a 3400W propane Generac that is on the small side. I would expect to pop a breaker of have other troubles if we were running any 3 (or maybe 4 depending on current draw) of the following high current appliances at the same time:

electric element in the water heater
air conditioner
electric space heater
heat strip in the AC unit
microwave
convection oven
hair dryer
refer on AC
electric fry pan
the 60A battery charger in the converter
COFFEE MAKER

My guess is your high tech coffee maker shuts down when is senses low voltage and you've got several things running. I would expect you to have the same problem at some campgrounds when shore power voltage drops under high loads from multiple RVs on the same branch circuits.

Mike

whemme · Post by **whemme** » Thu Dec 29, 2011 12:14 am

DBrown,

If you generator is setup properly, the frequency of its AC output voltage should stay between 58 and 62 Hz with 62 Hz being the highest frequency with no load on the generator and 58 Hz being the lowest frequency when the generator is loaded to the maximum. If you have an Onan generator, the maximum rated load will be 4000 watts and if you have a Generac generator the maximum rated load will be 3600 watts. Also, the AC output voltage under no load should be a maximum of 120 vac and a minimum of 110 vac. If your generator is LP gas powered, then their load ratings are smaller yet.

You should use a good digital voltmeter that will also measure frequency to check the output of your generator. The frequency of the AC voltage at your shore line pedestal is fixed at precisely 60.0 Hz.

I have never heard of a coffee maker that was such high tech that it may refuse to work if the frequency of the AC voltage supplying the power to it is off the 60 Hz frequency too much but I guess anything is possible. Look as the specifications for the coffee maker that you have to see if the AC power frequency is critical. Also, as someone else stated, try a different model coffee maker.

Normally your generator will be able to power two major loads such as the air-conditioner and the microwave oven running at the same time. However, if you were to add a 3rd load such as a toaster, hair dryer, or your coffee maker, then the generator can't handle all three loads and the 30-amp circuit breaker on the generator will open after a couple of seconds.