1989 LD Model 6336 Power Converter November 21, 2008, 08:03:56 pm Yahoo Message Number: 97443I recently had a tech. check out my propane heater. Turned out that the thermostat had gone bad and that was an easy fix. In the process of checking things he tells me that measuring at the converter box he found 13.08VDC with shore power on, and 12.80VDC with shore power disconnected. He also reported 11-30VAC on DC ripple and says I must have the Model 6336 Power Converter replaced. I should think that 13.08VDC would charge the house batteries, but maybe not very quickly. I don't know what the 11-30VAC on DC ripple can cause in the way of problems, and he was rather obtuse about explaining it to me. Frankly, I have no idea what VAC on DC ripple is all about, or what it can do to other devices. I was also a bit put off by his minimum labor charge of $95 plus a service call of $35 to check out the heater. He is a mobile RV service and we no longer have a fixed base RV service agency in town.I have no solar panels and no TV, just the in-dash radio. The house batteries seem to be charging well on shore power and while driving. What are the thoughts of you who are electronics savvy? I looked at the Parallax/Magnetek 6336 online replacement PDF and it looks easy enough to change the unit out if I need to.Many thanks, Gary in Chico, CA
Re: 1989 LD Model 6336 Power Converter Reply #1 – November 22, 2008, 12:26:01 am Yahoo Message Number: 97452Quotefound 13.08VDC with shore power on, and 12.80VDC with shore power disconnected. He also reported 11-30VAC on DC ripple and says I must have the Model 6336 Power Converter replaced. I should think that 13.08VDC would charge the house batteries, but maybe not very If that ripple reading is correct, then the converter filter capacitor must be bad. Your DC output is no longer filtered, and that could damage radios, TV's, and other electronic devices. That model also has primitive battery-charging capabilities, and will boil off electrolyte if left connected to shorepower, even if you install a new converter. However, there are several replacement converters which will fit where the old one slides out and which do a better job of charging and protecting your battery, such as the Progressive Dynamics Inteli-Power PD-4635. If you don't have one, tho, I would invest in an inexpensive digital volt meter ($20 - $30). Switch it to AC and measure the output of your converter. It should read nearly 0 Volts if not broken. This will give peace of mind before deciding whether it needs replacing. As a bonus, the meter will prove very useful for checking all sorts of electrical problems down the line.Steve
Re: 1989 LD Model 6336 Power Converter Reply #2 – November 24, 2008, 11:45:37 am Yahoo Message Number: 97516Thanks Steve. I think I'll go ahead with the PD-463 swap. BTW, I do have a VOM and checked out the converter output both with, and without, shore power. The odd thing, at least to me, is that I get a reading of 26VAC when I disconnect the shore power. Anybody..? Where the heck is the AC reading coming from?Gary
Re: 1989 LD Model 6336 Power Converter Reply #3 – November 25, 2008, 08:09:55 am Yahoo Message Number: 97526Quotehave a VOM and checked out the converter output both with, and without, shore power. The odd thing, at least to me, is that I get a reading of 26VAC when I disconnect the shore power. Anybody..? Where the heck is the AC reading coming from?Gary What brand/model of meter do you have, Gary? If an older analog model, then it is possible it either has no input blocking capacitor for the AC ranges, or that capacitor is shorted. Most meters today have a 10 million Ohm input impedance, and a small value capacitor is all that is needed to block DC from the AC ranges. Older analog VOMs typically had an input impedance that was range-variable, and fairly low for low voltage ranges. They may have skipped the otherwise needed large capacitor to accurately read AC voltages as low as 50-60 Hz.Either way, a shorted or missing capacitor would shunt the measured voltage on to the rectifier, which would also pass any DC on to the meter and measure it along with the AC. I saw a DVM at Harbor Freight the other day for Steve
Re: 1989 LD Model 6336 Power Converter Reply #4 – November 26, 2008, 10:33:04 am Yahoo Message Number: 97536Thanks Steve. My older analog multimeter bit the dust a year ago so I bought one of those inexpensive DVM models from Harbor Freight. I suspect that it is very possible that the needed DC blocking hardware is missing on the DVM and I am reading passed on DCV as ACV on the meter. Just for fun, I'll see if a buddy had a better quality DVM and try his unit.Gary