I just got off the phone with tech support at KVH, a manufacturer of in-motion satellites for marine, RV, and military use.
The call was regarding one of their satellites that a customer of mine has. The satellite has a board failure internally, and this is the second time for this. I got the same response as last time, which was that it was a power quality problem.
This unit is powered from the 12v.d.c. system on the coach, and their specs indicate a broad operating voltage range. I checked everything again as they requested and all appears to be good.
Now for the good part....
They recommended that I get a isolated power supply, so that this doesn't happen again. So I ask if this is something that they sell, and supprisingly they don't. However, Radio Shack does and the tech goes as far as to give me a part # and price from Radio Shack. He then explains that it needs to be MODIFIED. The modification is simple he says, "all you need to do is break the third prong off the a.c. cord and then the system is isolated!! This will now give you the buffer you need".
I already have one of these on my bench, and it is a REGULATED d.c. power supply with a metal case. Can you believe that people are out spreading this crap!!
That system is just a mobil auto-tracking satellite dish that sits in the roof of an RV or similar. It's 12VDC powered by the vehicle. I don't understand where a 120 volt to (I assume) 12VDC power supply comes in. Are they saying to power the system with this instead of the vehicle power? I assume also that the vehicle has a 120 volt generator hence your question about a ground prong?
I have found that a complaint on paper takes on a life of its' own. If the "help desk" actually told you to clip the ground prong...well, e-mail them. You can be pretty sure that your complaint will be addressed.
hbiss, Yes this system is powered from the coach batteries, and they are claiming that the 12 v.d.c system on the coach is providing dirty power.
The coach also has a Trace inverter/ converter that provides 120 v.a.c from those same batteries when genset or curb power is not available, and of course it charges those batteries when power is available.
Incuded in this sytem is an auto start for the genset which allows you to run of the inverter, albeit in a limited state, until the batteries reach a certian voltage, at which time the genset starts and charges the bateeries. From there the cycle continues.
Sorry to have strayed so far from the original discussion. I guess in my original post I was trying to express my disbelief in what I heard the tech say: "cut of the ground" more so than look for advice. Of course, I am extremely grateful for all the advice you guys could dish out.
P.S. I should send you some pictures of the mess the wiring is in on these things for those that have never seen it. This customer has a Featherlight transporter (as used by NASCAR teams), a Prevost Coach (extremely high-end, think country music star) and a 20'x 110' luxury houseboat. The poor quality of the way these things are built would amaze you, especially considering the price tags!!!