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Stavey22's avatar
Stavey22
Explorer
Nov 25, 2019

Converter Nichrome Wire Break

Hello, i recently got an 87 sunline t1660 that came with a B-W 3200 serires 3230Ul converter charger. It worked find to charge my batteries for some time but saturday after a running the lights for quite some time and the furnance most of the night off my batteries i had run down to about 12.1v.

I plugged it back in to ac from the garage (not generator) and was checking on it every now and then and realized that it charged to 12.4v and stopped.

The converter was still humming and producing DC as i could disconnect my batteries and power the camper. Although it was not producing any type of charging current.

After removing the converter i found that the Nichrome wire had melted broken the circuit between a flat black part which i think is a control module and the old style ceramic ballast resister (Chrysler auto Pat no. 254186).

The only thing that i have changed in the camper since i got it and successfully charged a couple dozen times is replacing all of the cabin lights with LED, added a 12v cigarette lighter on a switch from a light curcuit (off during charging) and a cheap amazon battery voltage meter directly from the battery (on during charging).

Does anyone have any ideas as to why this wire overheated and went into an ancient safe mode.

Batteries are 3 everstart maxx group 29 in parallel.

Thank you, hopefully that was understandable

edit- i do have a 12v milwaukee battery charger plugged into the ac outlet in the cabinet. not sure if that changes anything but im pretty sure its still plugged in up there.
  • BFL13's avatar
    BFL13
    Explorer II
    Nov 25, 2019
    You got down to 12.1v "loaded" and they came back to 12.4 unloaded, which is normal.

    You can still get by with the converter without the charger part working by using your battery charger as required. (The charger is not good for continuous duty at 13.6v like a converter is, it charges up the batteries and then shuts off or you unplug it.)

    Or, you can by-pass the old thing and use a new converter/charger that you can mount anywhere handy. EG:

    https://www.boatandrvaccessories.com/products/powermax-pm3-60lk-12-volts-60-amp-power-converter-battery-charger-w-led-light
  • cavie's avatar
    cavie
    Explorer
    Nov 25, 2019
    32 year old converter. Has it crossed your mind that it might just be time to update your equipment?? Do you still watch a 32 year old TV? Are you using a 32 year old Telephone? I'll be your car is not 32 years old. I'm all about fixing things but there comes a point it time..........
  • Stavey22's avatar
    Stavey22
    Explorer
    Nov 25, 2019
    I understand that i can replace it..

    The Nichrome wire got hot an separated as a safety measure due to a resistance issue.

    I have found that this was most likely the shunt to the controller previous the ballast.

    Was looking for constructive advice on finding what caused the problem assuming someone probably has had the same issue some at some point. Replacing parts without knowing what caused the issue is an ignorant waste of time and money.
  • Darryl_Rita's avatar
    Darryl_Rita
    Explorer
    Nov 25, 2019
    The NiChrome didn't get hot and melt from a resistance issue, it melted from a current issue. Have the battery terminals ever been removed while the RV was plugged in? Quick short to ground would do it.
  • MrWizard's avatar
    MrWizard
    Moderator
    Nov 25, 2019
    The trailer was OEM , WITH ONE 12v battery
    Simply put, 3 batteries with that low an SOC (state of charge), was too High of a continuous
    Amp draw for that converter
  • Chris_Bryant's avatar
    Chris_Bryant
    Explorer II
    Nov 25, 2019
    I believe there is supposed to be a self resetting circuit breaker there- not a piece of nichrome wire. If the breaker went bad and someone just removed and bypassed it....

    The schematics and service manual for that can be found at http://parallaxpower.com/archived-tech-docs/#

    B & W begat Magnetek, Magnetek begat Parallax Power.
  • Stavey22's avatar
    Stavey22
    Explorer
    Nov 25, 2019
    Darryl&Rita wrote:
    The NiChrome didn't get hot and melt from a resistance issue, it melted from a current issue. Have the battery terminals ever been removed while the RV was plugged in? Quick short to ground would do it.


    I believe you got that right on. I did get one small spark in the days prior when i was moving things around venting my boxes. No blown fuses and everything seemed to work so i thought i was in the clear.

    After looking at the photo of unit with labels someone linked me to i found that the part i was referring to pervious the nichrome wire was the SCR. I soldered the wire back to the tab on the ballast and it seems to be working so far. Im monitoring it closely however as i am unsure if the wire will get hot enough to melt the solder.

    Thank you to everyone who gave constructive responses.
  • BFL13's avatar
    BFL13
    Explorer II
    Nov 25, 2019
    "Thank you to everyone who gave constructive responses."

    Since the OP is such a nice person, I feel it is only polite to mention his three 29s are probably in bad shape by now.

    He can confirm that with an hydrometer if he has one. (Of course he does!)

    If they are not all up to proper SG when he believes they are fully recharged, then being polite again, I would suggest he refer back to the link in my post above (if that is not being too rude).
  • time2roll's avatar
    time2roll
    Nomad
    Nov 26, 2019
    Time for a new converter, a properly sized fuse and correct wire that can handle full rating.

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