Control Techniques UD53 User Manual page 8

2.7 Risk analysis
In any application where a malfunction of the Drive could lead to damage,
loss of life or injury, a risk analysis must be carried out, and where necessary,
further measures taken to reduce the risk. This would normally be an
appropriate form of independent safety back-up system using simple
electro-mechanical components.
2.8 Signal connections
The control circuits are isolated from the power circuits in the Drive by basic
insulation only, as specified in IEC664–1. The installer must ensure that the
external control circuits are insulated from human contact by at least one
layer of insulation rated for use at the
If the control circuits are to be connected to other circuits classified as
Safety Extra Low Voltage (SELV) (eg. to a personal computer), an additional
isolating barrier must be included in order to maintain the SELV
classification.
2.9 Adjusting parameters
Some parameters have a profound effect on the operation of the Drive.
They must not be altered without careful consideration of the impact on
the controlled system. Measures must be taken to prevent unwanted
changes due to error or tampering.
4
supply voltage.
AC
UD53 User Guide
Issue code: 53nu3