289761-01   ADAPT Emergency Shutdown Device

The 3701/55 Emergency Shutdown Device, (ADAPT ESD) is a safety PLC with a graphical logic programming interface and
integrated overspeed detection. ADAPT ESD is designed for emergency shutdown of rotating machinery such as steam,
gas, and hydro turbines, expanders, and other process equipment.
ADAPT ESD is a compact, standalone, triple-redundant, safety shutdown device that is designed to meet a broad range of
user scenarios and applications. The design offers an electrical and mechanical package with attention to reliability and
availability as well as extensive self-diagnostics and compliance to industry standards.

Inputs to the system are processed using three CPU modules to provide triple modular redundancy (TMR). Each CPU
processing module processes two unique speed input channels, for a total of six speed channels for the system. The
processing modules also monitor an array of 32 discrete (DI) and process variable (PV) signal inputs. Twelve channels of this
input signal array may be configured either as discrete inputs or 4-20 mA analog inputs. Remaining channels in the array are reserved for discrete input signals only.

370140 177896-05

Machinery shutdown functionality of the 3701/55 ADAPT ESD system is actuated by TMR relay output modules. Each relay
output module has five relays with a level of configurability that accommodates a variety of applications and
requirements. Four of the five relays in each module are used to annunciate system logic. The remaining relay reflects the
OK/NOTOK status of the associated protection path. The Bently Nevada* Monitor Configuration software provides a
graphical interface to configure relay logic. The state of each relay is determined by the system inputs and

configured system logic in conjunction with the control state of the relay.

Relay control states depend on the application, and may be set as normally energized/deenergized and independent one-out-of-one,
(1oo1), voting or TMR two-out-of-three, (2oo3), voting. Each CPU module in the system has two,
internally powered, 4-20 mA recorder outputs controlled by the full-scale speed set by the
user through the Monitor Configuration software.