Fender PD-250 Passport going into protect mode when running off 500 Watt Inverter

[tfs2015]

Dear members in the previous thread that I started, I posted about my Fender PD-250 Passport PA System. All the previous problems are fixed on it now, but now I have new problem that keeps coming up with it. I was running it off of a 500 Watt Power Inverter during a parade this past week. Anytime I would turn the output volume up to high it would go into PROTECT mode. Then I would have to shut it off wait a few minutes and then turn it back on. It would run for a little while and then go into PROTECT mode again. At home plugged into a normal household outlet it can run all day long with no problems at all. Should I turn the LEFT and RIGHT BIAS down on the power amp board so that it does not draw as much current? The specs on the inverter are:

• Model: EN500 Energizer
• Input: 12VDC 54A
• Output: 115VAC 60Hz 4.4A 500W

Thanks
Tom

[budm]

Re: Fender PD-250 Passport going into protect mode when running off 500 Watt Inverter

The Bias setting is set when the unit is in idling mode (no signal input), when the unit is fed with signal, then the bias in the output will vary with the amount of signal for the required out put to drive the speakers, lowing the bias current will not reduce the current draw when the amps are demanded to put out the required power. Less drive to the speakers = less current draw by the amplifiers = less current draw from the power supply = less current draw through the Inverter. 500W Inverter (it claims 500W continuous) does not look to be enough head room when high power are demanded by the amplifiers.
Since it runs fine all day on AC SINE WAVE with no problem, then it has to be due to the step sine wave inverter problem.
Did you run the same setup before the repair without any problem.

[japlytic]

Re: Fender PD-250 Passport going into protect mode when running off 500 Watt Inverter

I have read in a Jaycar catalog that one of the things which are best for pure sinewave inverters is mains powered PA equipment.

[CapLeaker]

Re: Fender PD-250 Passport going into protect mode when running off 500 Watt Inverter

Probably you run out of juice from the cheap modified sine wave inverter. Some things don't run that great on modified sine wave inverters as they consume more power on that modified sine wave than on a true sine wave. There could be also a small problem on how you connected the inverter to the battery. Like is the inverter close to the battery or are the battery cables a half mile long etc.
I really don't think it is the PA's fault.

[budm]

Re: Fender PD-250 Passport going into protect mode when running off 500 Watt Inverter

Not sure if this true or not.
http://www.themagiccafe.com/forums/v...44221&forum=11