C.P. SENTINEL AUTOMATIC TYPE CATHODIC PROTECTION RECTIFIER MANUAL
INTEGRATED RECTIFIER TECHNOLOGIES, INC.
Doc #: APC0010
Rev. 3.0, November, 2004
Page 8 of 22
RECTIFIER OPERATION MODES
Depending upon the Model and the Options supplied with the rectifier, the C.P. SENTINEL
Automatic Rectifiers are available with the following modes of operation:
CONSTANT VOLTAGE MODE: (SUPPLIED ON ALL MODELS
)
In this mode the rectifier control circuitry automatically adjusts the rectifier output to maintain
the VOLTAGE at the preset level. In this mode, the Current Set potentiometer determines the
current limit. When operating in this mode, the RED LED is illuminated.
CONSTANT CURRENT MODE: (SUPPLIED ON ALL MODELS
)
In this mode the Rectifier control circuitry automatically adjusts the rectifier output to maintain
the CURRENT at the preset level. In this mode, the Voltage Set potentiometer determines the
voltage limit. When operating in this mode, the GREEN LED is illuminated.
IR-FREE POTENTIAL MODE: (OPTIONAL
)
In this mode the Rectifier control circuitry automatically adjusts the rectifier output to maintain
the Reference Electrode to Structure POTENTIAL at the preset level. The Reference
Electrode to Structure POTENTIAL is maintained free of the error caused by current flow in the
anode-cathode circuit. IR-Free Potential mode is available on non-filtered single phase
rectifiers only. In this mode, the CURRENT Set potentiometer determines the current limit and
the VOLTAGE Set potentiometer determines the voltage limit. When operating in this mode,
the YELLOW LED is illuminated.
“ON” POTENTIAL MODE: (OPTIONAL
)
In this mode the Rectifier control circuitry automatically adjusts the rectifier output to maintain
the Reference Cell to Structure POTENTIAL at the preset level. However, the Reference
Electrode to Structure POTENTIAL is maintained while there is current flow in the anode-
cathode circuit. In this mode, the Current Set potentiometer determines the current limit and
the Voltage Set potentiometer determines the voltage limit. When operating in this mode, the
YELLOW LED is illuminated.
MANUAL MODE: (OPTIONAL
)
Rectifiers equipped with this option are supplied with a conventional manual tap-adjusted
transformer in addition to the automatic control circuitry. This mode permits the operator to
control the rectifier output by gating ‘on’ the Silicon Controlled Rectifiers to conduct as
conventional diodes. Manual rectifier output control is achieved by switching the Automatic-
Manual Switch to the Manual mode position and then adjusting the transformer secondary
taps.
NOTE:
C.P. SENTINEL Automatic Rectifiers encompass full galvanic isolation of the Reference
Electrode and Structure input signals. Therefore it will be necessary to connect separate
lead wires for the REFERENCE Electrode and STRUCTURE sensing.
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