powerstat inverter problem

[Dave Cunningham]

Hi everyone, I am having a problem with my Powerstat ( Xantrex) Puresine 3000 inverter, it just started acting up on my last trip.  Out of the blue the fault alarm started to sound, and it is showing that the battery voltage is too high.  It is showing the voltage at about 16 volts, but then when you shut off the coach the display shows only about 14 volts.  The only way I could get the alarm to stop sounding was to run the inverter and plug in a small electric heater while driving.  I do have the manual, but it doesn't seem to be that helpful for this problem.

Any ideas?

Thanks,

Dave C

[Gerald Farris]

Dave,
The first question is, what is the voltage at the batteries when you are driving? If this only happens when you are driving, your inverter may not have anything wrong with it. If the engine alternator's voltage regulator is malfunctioning and you may really have 16+ volts at the batteries, and if so the inverter is functioning as designed. We need more information to help you.

Gerald

[Dave Cunningham]

Hi Gerald, the voltage while driving is about 16, you could be right about the voltage regulator , I will check that out, although the voltage gauge on the dash only shows 13 to 14 volts

[Edward Buker]

Dave,

Looks like you and Gerald are hot on the trail of the voltage regulating problem. By putting the resistance heater load on the inverter you are able to drop the output voltage back below the alarm spec of the Xantrex, but you are doing that by putting a severe load on the inverter and alternator.  The alternator is trying to hold the output at 16v (for your case) and the best it can output is 13 to 14V under load.

Whatever the amps are at 120V, multiply that value by a factor of 11 and you will be close to the DC amps that the alternator has to supply for the inverter load alone. Then you have to add the 12V coach load, that is being used over the road, to power all the other 12V needs. 100amps, which might be a sustained safe load for a 150 amp alternator, gets consumed fairly quickly.

You are between a rock and a hard place with possible over voltage DC damage to some 12v equipment vs a possible burned out alternator scenario. I would avoid running the coach until this is fixed if at all possible.

Later Ed

[Gerald Farris]

Dave,
Like I have said on the forum several times before, the dash gauges are for "Entertainment Purposes Only". By that I mean that they are normally to inaccurate to be depended upon. If your Aladdin says that your 12V circuit is running at 16V when you are driving, it really is. Get the voltage regulator replaced before you damage something. The alternator is probably already damaged, because running with a space heater on has probably overloaded it to the extent that the stator has been overheated so badly that it needs to be replaced.

Gerald

[Dave Cunningham]

thanks guys, I am definetely going to figure this out before going anywhere in the coach, hopefully it is just as simple as repairing or replacing the alternator