Basic working techniques
The Husqvarna PG 680/820 ﬂoor surfacing machines are
designed for wet or dry grinding of marble, terrazzo,
granite and concrete. Their applications range from rough
grinding through to a polished ﬁnish.
It is highly recommended to use the Husqvarna DC 6000
dust extraction system for complete dust control.
Variable speed drives/frequency
WARNING! The Speed drive/Frequency
converter may only be used by
authorized personnel. Risk of electric
Each Husqvarna PG 680 & 820 is equipped with 2
variable speed drive or frequency converter. This unit is
incorporated into the machine for the following reasons:
Manipulate incoming power to enable increase/
decrease in speed & direction change.
Regulate current and voltage supply to the motors to
ensure motors run at optimum levels (e.g. torque
Monitors incoming power to ensure suitability for
machine and application being performed.
Controls current being drawn by motors to ensure
motors are running within safe operational limits (to
prevent damage to motor).
Monitors load on machine to ensure the grinder is not
being overloaded thus offering protection for belt,
bearings and other internal components.
Protects motors from faulty power supply (e.g. running
on 2 phases).
Identiﬁes electrical faults with the machine and
registers fault code.
Has monitoring menus that help isolate cause of
potential electrical faults.
Monitoring menus also enable operator to gauge how
hard machine is working. Whilst it is not essential for an
operator to intimately know every feature of the variable
speed drives or frequency converters, it is useful to be
familiar with both the fault codes as well as some of the
20 – English
Each variable speed drive or frequency converter has a
keypad which will appear as illustrated below when the
machine has power connected to it.
Run direction (fwd or rev)
Indicates if unit is either stopped or running
12 Output mode (Hertz in this example)
13 Output value
14 Stand by ready indicator