Specifications and Ordering Information
3500/53 Electronic Overspeed Detection System
Description
Bently Nevada’s Electronic Overspeed Detection System
for the 3500 Series Machinery Detection System provides
a highly reliable, fast response, redundant tachometer
system intended specifically for use as part of an
overspeed protection system. It is designed to meet the
requirements of American Petroleum Institute Standards
670 and 612 pertaining to overspeed protection.
3500/53 modules can be combined to form a 2-out-of-2 or
2-out-of-3 (recommended) voting system.
The use of redundant power supplies in a 3500 rack
containing the Overspeed Detection System is required.
Specifications
Inputs
Signal: Each Overspeed Detection module
accepts a single transducer signal from
a proximity probe transducer or
magnetic pickup. The input signal
range is +10.0 V to -24.0 V. Signals
exceeding this range are limited
internally by the module.
Input
Impedance:
20 k Ω.
Power
Consumption:
8.0 Watts, typical.
Transducers: Bently Nevada 3300 8 mm Proximitor®;
3300 16 mm HTPS, 7200 5 mm, 8 mm,
11 mm, and 14 mm Proximitor®; 3300
RAM Proximitor®, or
Magnetic pickups.
Outputs
Front Panel LEDs
OK LED: Indicates when the 3500/53
Module is operating properly.
TX/RX LED: Indicates when the 3500/53
Module is communicating with
other modules in the 3500 rack.
Bypass LED: Indicates when the 3500/53
Module is in Bypass Mode.
Test Mode LED: Indicates when the 3500/53 is in
Test Mode.

3500/53