PG Drives Technology VR2 series - Drive Motors and Battery Requirements

VR2 CONTROL SYSTEM
SK77898/2
PG DRIVES TECHNOLOGY
34
6 Drive Motors
The control system is designed to be connected to permanent magnet DC motors,
fitted with suitable gearboxes and solenoid brakes.
In order to optimize the performance of the wheelchair, the control system must be
matched to the motor terminal impedance. This matching is implemented by
programming the control system. The parameter for adjustment is Motor
Compensation. Refer to Chapter 3 for details.
The Motor Compensation value should be set in accordance with the armature
resistance of the motor and all cables and connectors between the VR2 and the
motor. The value is set in milli-Ohms (mW). A recommended value is:
 70% of the (armature resistance + cables and connectors)
Motor manufacturers should be able to supply figures for armature resistance and
cable and connectors may typically be 40mW.
Example:
Motor has armature resistance of 200mW
Cables and connectors are 40mW
Set Motor Compensation to 0.7 x (200 + 40) = 170mW
Failure to match the control system with the motors may result in poor control
characteristics.
If you have any doubts about the suitability of a particular motor type or you need
advice on measuring motor impedance, contact PGDT.
The chair manufacturer is responsible for ensuring that the
control system is matched to the motor resistance. Failure
to do this may result in poor control characteristics, which
in extreme instances can make a chair uncontrollable and
potentially unsafe. PGDT accepts no liability for losses of
any kind arising from failure to comply with this condition.
The chair manufacturer is responsible for always ensuring
that any replacement motors or gearboxes are fully
compatible with the originals that the control system was
designed to match. Failure to do this may result in poor
control characteristics, which in extreme instances can make
a chair uncontrollable and potentially unsafe. PGDT accepts
no liability for losses of any kind arising from failure to
comply with this condition.
Users must not move a control system from one chair type
to install it on a different chair type. Control systems with
different part numbers may have both hardware and
software differences to ensure that they are compatible