Can Low Voltage Burn Out Applicances?

[johntelling]

On Saturday evening, a large tree took out the power in our area. Not to worry; I carried our coffee maker out to the motorhome the next morning and made coffee.

There was an acrid smell, which turned out to be a component on the coffee maker's circuit board frying!

I measured the voltage (no generator running, just power from the invertor) and got 117 VAC.

Could this be the problem, and if so, can it be fixed? The motorhome is a 2005 Excursion.

Thanks!

JT

[dickandlois]

Voltage level is OK. Murphy's Law, maybe just time for the Coffee maker to fail.

Can not think of a good reason where the inverter would takeout the circuit board.

Some speculation-- The only thing that comes to mind. What is the status of the house batteries?

The batteries being low could reduce the voltage from the inverter under a higher load and an increase in current might have been the cause,but one would think that a fuse would have failed inside the coffee maker had that been the case.

Was the coach plugged into shore power when the tree took out the power?

Power surge could have done some damage to the charger / inverter,but unlikely because the current reading is OK.

A good test of loaded power level would be to monitor the voltage from the inverter with the microwave running as the load. What is the voltage? if it is between 112 to 120 volts,the inverter system should be OK.

Rich.

[kingfr]

If your inverter is a Modified Sine Wave inverter instead of a pure sine wave inverter, it can easily destroy a coffee maker if the coffee maker has any electronics in it, such as a timer for starting it or stopping it. I destroyed two coffee makers that way before I found out the cause. Our coach came with a 2k Xantrex MSW inverter. We could not use digital clocks on inverter, and the microwave had a strange hum when on inverter. When we dumped our Norcold refer for a Whirlpool Residential Refer, we changed out the Xantrex for a 2800 Magnum pure sine inverter. No more clock issues and the microwave sounds just like it does on shore power. OBTW, 117 Volts is no problem at all. Our Energy Management System does not shut down power unless it is below 104 volts or above 132 volts. Most A/C appliances are built to a 115V design point.

[RVerOnTheMove]

117V is great power so that's not the issue.

If it is a Wal-Mart branded Mr. Coffee, then it was junk to start with (according to the Wal-Mart employees) and we burned up 2 of them while on inverter. No other coffee maker has had any similar issues.

[ploiselle]

If it is a modified sine wave inverter, an inexpensive multitester will not give you the correct voltage. As indicated below, it will read between 2% and 20% low. If your meter is reading 20% low, you could have a voltage of 146 volts.

(80% of Voltage = 117 ---- Voltage = 146 volts)

From "]http://www.powerstream.com/inFAQ.htm] www. powersteam.com

Q: Why don't I measure rated voltages when using a multimeter on my modified sine wave inverter?

A. The rated voltage is an RMS (root mean square--they square the value to make sure it is always positive, then average it, then take the square root of the average to make up for having squared it in the first place) measurement. Most multimeters are designed to give correct RMS readings when applied to sine waves, but not when they are applied to other waveforms. They will read from 2% to 20% low in voltage. Look for a voltmeter that braggs about "True RMS" readings.

Paul