Curtiss-Wright | PG Drives Technology
SK77981-14
103 | R-net Technical Manual | Chapter 3 – Programming
There are maximum permissible values, which must not be exceeded, for each of these parameters. These values are shown in
the table below.
PM60
PM80
PM90
PM120
Maximum Current Limit
60 Amps
80 Amps
80 Amps
100 Amps
Boost Drive Current
60 Amps
80 Amps
90 Amps
120 Amps
Boost Drive Time
- -
- -
10 Secs
10 Secs
WARNING:
The values in the table above should never be exceeded. Doing so will invalidate the warranty and affect the long-term
reliability of the Power Module.
12.2
CURRENT FOLDBACK THRESHOLD, CURRENT FOLDBACK TIME, CURRENT FOLDBACK LEVEL
These three parameters can be used to protect the wheelchair motors from overheating. The parameters are closely related, so
are dealt with in one section.
Current Foldback Time sets a period of time, which if exceeded by the software timer will initiate a reduction in the Power
Module’s maximum current output.
The programmable range is 0 Seconds to 250 Seconds in steps of 1 Second.
Current Foldback Level sets the level of current output reduction, as a percentage of Maximum Current Limit, that will result.
The programmable range is 25% to 100% in steps of 1%.
Current Foldback Threshold sets a level of current, which, if exceeded, will start a software timer running.
If the current drops below the level set by current foldback threshold, then the software timer will decrement each second.
The programmable range is 10A to Maximum Current Limit (see previous section) in steps of 1A.
After the reduction has occurred, the maximum current output will remain at the reduced level for a period of 5 times Current
Foldback Time. This is a typical period that is sufficient to allow motors to cool.
The graph following shows the relationship between the parameters.
