3701/55 323174-01 ADAPT (ESD) Emergency Shutdown Device

Description
The 3701/55 Emergency shutdown Device, (ADAPT ESD) is asafety PLC with a graphical logic programming interface andintegrated overspeed detection. ADAPT ESD is designed foremergency shutdown of rotating machinery such as steam,gas, and hydro turbines, expanders, and other processequipment.
ADAPT ESD is a compact, standalone, triple-redundant, safetyshutdown device that is designed to meet a broad range ofuser scenarios and applications. The design offers anelectrical and mechanical package with attention toreliability and availability as well as extensive self-diagnosticsand compliance to industry standards.
Inputs
Inputs to the system are processed using three CPu modulesto provide triple modular redundancy (TMR). Each CPUprocessing module processes two unique speed inputchannels, for a total of six speed channels for the system. Theprocessing modules also monitor an array of 32 discrete (Dl)and process variable (Pv)signal inputs. Twelve channels ofthis input signal array may be configured either as discreteinputs or 4-20 mA analog inputs. Remaining channels in thearray are reserved for discrete input signals only.
Outputs
Machinery shutdown functionality of the 3701/55 ADAPT ESDsystem is actuated by TMR relay output modules. Each relayoutput module has five relays with a level of configurabilitythat accommodates a variety of applications andrequirements. Four of the five relays in each module are usedto annunciate system logic. The remaining relay reflects theOK/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/de-energized 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.

3701/44 177989-01