Well, my three-year-old Nilfisk suddenly stopped working, right in the
middle of a big project of course.  So I called Nilfisk and got some good
information.  I talked to three people, all of whom were helpful. But if you
need to call them talk to Vince, he was very informative.  He told me that
they changed from a 7 amp motor to an 11 amp, and then found that the old
speed controller was burning out the motor when used at low speeds.  So they
found a new controller that would only allow you go down to about 50% of
full power.  They are now using another new controller that will go down
further, to 25% or so.  This is not as far as the old controller (which was
about 10%), and it's 25% of a bigger motor so the suction will still be
stronger than we're used to.  It's too bad they switched motors, but I guess
most of their customers want more suction.  I guess it's only museum folks
who use the speed controller.

I found out that my machine has the old controller and the smaller motor,
which was a relief.  I sent the top of the machine to Nilfisk for repair,
and I had it back just over a week later.  Luckily, it was just my power
cord that was bad, they replaced it and did it under warranty.

In the meantime, I used my other HEPA vac with the Variac speed controller
that I mentioned in my previous post.  It worked great, pulling the motor
down to almost nothing.  I would definitely use this in preference to a
newer Nilfisk.

Deborah Bede
Stillwater Textile Conservation Studio, LLC