Thread: Generac 7500
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Fred McKenzie Fred McKenzie is offline
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Default Generac 7500

In article . com,
wrote:

OK ! I'm in the US and this unit worked when I bought it used, I was
wrong about the voltage regulator. I have the used one I replaced and
the screw is not to adjust the voltage, it's to secure the heatsink to
a component on the board. I looked on the side of the output panel and
found the adjustment on the 83970 and adjusted it. The most voltage I
get out of the 120 0ut is 68v and I adjusted the trim to give me 120
out of the 220 receptacle. That gives me 60v out of the 120 outlets.
This unit uses a rotor and a stator, so I can't see how it would have
fields. The original diagnostic by a friend who is an electrical
contractor was that one of the fields might be bad, therefore the 1/2
power. I read something about flashing the fields, but don't think this
applies to me. I was told by the local tech that repacement rotors and
stators are usually 2 to 3 hundred bucks, before the labor costs. It
would be nice to find a unit with a blown engine, buy it and swap out
the generator. Any more advice is welcome, and thanks to all.


Ellombris-

If you needed to flash the field, there would be NO output, so don't
worry about doing that.

Have you inspected the brushes to see if they might be worn down or have
a frayed wire that might be touching the frame?

A shorted battery charger rectifier diode might cause low output, but
probably wouldn't zap the 84132 module.

Some 7500 Watt Generac models had winding resistances in Ohms as
follows, per the Clymer volume 2 manual:

Rotor 7.6-9.1
Main AC Power .20-.25/.20-.25
Excitation(Dpe) 1.56-1.91
DC Battery Charger Winding .05-.09/.06-.11

The Excitation (Dpe) winding supplies AC voltage to the 84132 module,
which rectifies it and supplies current to the field via the brushes.

If you have time, visit
http://www.smokstak.com. There is a search
function there you could use to find a wealth of information.

Fred