Monitoring Your Critical Lifting Equipment

American Crane's SafWatch® Device can help you enhance your new or existing equipment with increased safety protection. The SafWatch® provides a fail safe control system which exceeds the requirements of NUREG 0554 and ASME NOG-1.SafWatch® allows you to take the safety of your equipment to the next level.

SafWatch® Monitoring Includes:
  • Operation in excess of design speed as well as monitoring operator requested speed compared to actual speed
  • Incorrect movement including wrong direction, wrong response to operator request, lack of movement and unauthorized motion
Additional Features Include:
  • Independent Hard Wired Watch Dog Circuit monitoring SafWatch® processors and power supply
  • Unique Encoder Line Receivers to provide feedback for hoist motor and drum direction and speed
  • Rack mounted Modular Input / Output Units providing flexibility by allowing a mixture of input and output types
TECHNICAL SPECIFICATIONS

Overspeed

Detect Operation in Excess of Design Speed
  • Detect overspeed in excess of 115% of critical lift speed
  • Detect overspeed in excess of 115% of non-critical lift speed
  • Brakes are automatically applied when an overspeed fault is detected
Drive Train Discontinuity

Detect Difference Between Drum and Motor Speed
  • Detect incorrect drum movement (Speed Differential)
  • Response time may vary based on existing driveline design
  • Brakes are automatically applied when drive train discontinuity is detected
Differential Motion

Compare the direction and speed of the hoist to the direction and speed initiated by the operator
  • Response time may vary based on existing drive acceleration, deceleration and operator reverse plugging
  • Brakes are automatically applied when differential motion is detected
Commanded Not Operated

When the equipment does not respond to a command to operate
  • Detect lack of drum movement when drum movement is initiated by the operator
  • Detect failure of encoder feedback and control circuit
  • Response time may vary based on existing driveline design and drive torque proof testing
  • Brakes are automatically applied when a commanded not operated fault is detected
In Motion

Operator notification of hoist up and down motion that is independent of the hoist control circuit providing compliance with NOG6411.6(f)
  • Detect upward or downward drum movement and prompt operator
Uncommanded Motion

Detect drum movement not initiated by operator input or drum movement in the wrong direction
  • Detect incorrect upward or downward drum movement
  • Detect reversal of drum rotation
  • Response time may vary based on hoist drive deceleration or operator initiation of reverse plugging
  • Brakes are automatically applied when an uncommanded fault is detected
Watch Dog Circuit

Independent hard wired circuit to detect failure of the SafWatch™ processors and power supply
  • Detect 5 VDC and 12 VDC power supply failure
  • Detect MCU (Microchip PIC series Microcontroller) hardware or software failure
  • Detect CPLD (Complex Programmable Logic Device) hardware or software failure
  • Brakes are automatically applied when a watch dog fault is detected
Encoder Line Receiver

Unique encoder line receivers utilized for hoist motor and drum direction / speed feedback to increase reliability and fault detection
  • Allows the use of quadrature differential encoders for long distance operation
  • +/-15kV ESD (Electrostatic Discharge) protection, increased common mode rejection
  • Alarm flags to indicate open, shorted line conditions, excessive common-mode voltage range, and low-signal strength
  • Brakes may be automatically applied when an encoder alarm is detected
Modular Input / Output Units

Rack mounted modular I/O units to allow a mix of analog, digital, and serial inputs and outputs at different voltage levels
  • UL recognized rack and I/O modules ranging from 5 VDC to 240 VAC
  • Up to 8 rack slots available for a total of 32 digital input or outputs
  • Analog and serial modules supported
Contact us at 1-877-877-6778
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