Safe Limited Speed - OEM Automatic AB

Chapter 1
Safety Concept
• The encoder is of the Sin/Cos type and is suitable for the desired
safety rating of the application.
An encoder that is suitable for SIL CL3 applications must:
– use independent Sine/Cosine signals.
– be incapable of producing simulated signals when under an
error condition.
– use simple or discreet circuitry with no complex or
programmable internal devices.
• The controller is not configured for auto transition to
encoderless commutation in the event of encoder failure.
• The motor controller must use the same encoder signals as
MSR57P relay.
• Encoder voltage monitoring in MSR57P relay must be enabled.
• The system design of the motor/encoder-to-load coupling
excludes shaft slippage and breakage as a dangerous failure
mechanism.
Single-encoder with Kinetix Drive
A safety rating up to and including SIL CL3, PL(e), and CAT 4 can be
achieved in an MSR57P relay single-encoder application when the
relay is used in conjunction with a properly-configured Kinetix Servo
Drive with Safe-Off and any motor/encoder combination that meets
the single-encoder application requirements on page 19.
Single-encoder with PowerFlex Drive
A safety rating up to and including SIL CL3, PL(e), and CAT 4 can be
achieved in an MSR57P relay single-encoder application when the
relay is used in conjunction with a properly-configured
PowerFlex 700S or PowerFlex 755 drive and any motor/encoder
combination that meets the single-encoder application requirements
on page 19.
20 Publication 440R-UM004A-EN-P - December 2008