Re: (ET) Charger bad

["Tim Humphrey" <hump evgrin com>]

OK, here's an update.

Ever have one of those "What the Heck" kind of experiences....?

I ordered two capacitors from Burdens Surplus Center. Put one into my
charger and got exatly the same indications that I got with my original
cap, so I tried the other one.

Still same thing, charger open circuit gets to 40v no higher. So I ordered
a brand new cap from Newark Electronics.

Put it in, still same problem. I'm thinking it must be something else, but
what? Everything points to a bad cap, maybe a bad winding in the tertiary
coil but I doubt it.

 Now my tractor has been down two weeks, and I've been playing musical
batteries with my 12 volt car charger, to keep them topped up in the
cold.

Well, a major snowstorm was predicted. So I figured I had better get the
ET put back together charger or no charger, before the snow came. Put the
charger back in, bolted the resistor pack(charger cover) back in place,
put the two front batteries back in and hooked them up. Checked system
voltage, 39.something or other, OK I guess, it should be able to do the
driveway, then I can play musical batteries with the car charger again.
But, plugged in the "bad" ET charger anyway -- Bam, shot right up to 43
volts. Now, this is with my "original" bad cap installed.

Went out in the morning and plowed the 7 inches of really heavy white
stuff. No problems, tractor must have been fully charged.

What is quite amazing actually, this is the first time this year that I've
needed to plow, it's the first part of February, we normally get 168"
annually. We're way behind schedule, with a total so far of only 48", 2 -
3" at a time. And today, the 17th, that 7 inches is gone. We're supposed
to get up to 10 in the next 18hrs, we'll see what happens.

Anyway, got done and plugged 'er in. Landis took control, and has been
running fine ever since (it's been a week). The only thing I can think is
I originally had a bad connection, and my troubleshooting procedures were
wrong! In fact, I'm pretty sure this is the case!!!



Important Lesson:

In order for the tertiary coil in a ferro-resonant transformer charger to
function, there has to be a load on the charger, you cannot check for peak
output voltage with the charger open circuited.

-- 

Stay Charged!
Hump
"Whether you think you can or think you can't, you are right!" --Henry Ford











>
>
> Tim Humphrey wrote:
>> Well, I noticed that my Landis controller was cycling quite
>> frequently. I checked the "level" gauge and it was right on the line
>> between green and white while on charge. The charger was outputting
>> about 39.5 volts, each batt is at around 6.5 volts.  I put a pair on
>> my 12 volt charger and they immediately started pulling 13 amps so I
>> figure they are quite low.
>
> Check the diodes as well, but it's probably the capacitor. Not a big deal
> to
> replace; my McMaster one is working perfectly.
>
> Chris
>
>
>>
>> I say about, because I was using a cheap analog voltmeter.
>>
>> So... I took the charger out of the tractor last nite, (what a job).
>>
>> My plans are to get a new capacitor, based on what I remember from
>> reading posts on this list.
>>
>> On the bench, with no load, the charger puts out about 32v, without
>> the cap, and 40 with the cap. I seem to recall that it should be more
>> like 45 with the cap, thus my reason for replacing it. Both diodes
>> check good even though they look like their 30 yrs old
>>
>> Mine happens to be the 4uf cap.
>>
>> While re-assembling the charger into the tractor, I plan to reconnect
>> the connections with a connector instead of terminal lugs. Any
>> suggestions?
>>
>> I have to replace every bolt I touched, which is par.
>>
>> Kind of ironic, ain't it Bob....
>>
>>