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Raychem-AR-H58692-ACS30UIT2Programming-EN-1805
Fail Safe:
THE FAIL SAFE CONTROL BUTTON TURNS THE POWER ON OR OFF TO THE
HEATING CABLE IF THE CIRCUIT LOSES ALL VALID RTDS.
When the last remaining sensor for control fails (or communication with the sensor is lost), the
ACS-UIT2:
•
Signals an alarm for the failure of the sensor
•
Changes control of the circuit to the fail safe control selected
•
Changes the control status display to indicate that control of the circuit is in the fail safe state
•
Records the events
When the sensor for control is returned to service, the ACS-30 controller signals the alarm has been
cleared, returns the circuit to its normal control mode, and records both of these events.
Range:
Power On or Power Off
Default:
Power On
External Override:
The dry contacts from a BMS system or external device may be assigned to the
circuit to de-energize the circuit to save power when it is not needed. All temperature and system
alarms are still active. Refer to Appendix 5.3 for further details.
Assigning RTDs
After the control mode and parameters have been set tap Setup|RTDs window to assign RTDs to
the circuit. When in line control mode you have the option of setting up to four RTDs for ambient
control. In this mode you can have up to three of the four RTDs set to monitor the pipe. For detailed
information on the RTD window refer to 2.2.3 Assigning and Sharing RTD Control and Monitoring on
page 30. Input from an external dry contact may also be assigned to override the system. Refer to
Appendix Section 5.3, page 130 for further details.
Fig. 3.47
Setup|RTDs window (Fuel Oil Ambient Control)
