IRT CP Instruction manual

C.P. SENTINELAUTOMATIC TYPE
CATHODIC PROTECTION RECTIFIER
INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
REV. 3.0 NOVEMBER,2004
SINGLE PHASE INPUT
MODEL:
CP – “ON” POTENTIAL CONTROL
CI – “IR FREE” POTENTIAL CONTROL
INTEGRATED RECTIFIER TECHNOLOGIES, INC.
15360 – 116 Avenue, Edmonton, Alberta, Canada T5M 3Z6
Phone: [phone] Fax: [phone]
Website: www.irtrectifier.com Email: [email protected]

C.P. SENTINEL AUTOMATIC TYPE CATHODIC PROTECTION RECTIFIER MANUAL
INTEGRATED RECTIFIER TECHNOLOGIES, INC.
Doc #: APC0010
Rev. 3.0, November, 2004
Page 1 of 22
INDEX
PAGE
INTRODUCTION 3
DELIVERY INSPECTION 4
PRE-INSTALLATION STORAGE 4
SAFETY PRACTICES 5
GENERAL INSTALLATION RECOMMENDATIONS 6
RECTIFIER CONNECTIONS AT SITE 7
RECTIFIER OPERATION MODES 8
THE SENTRY CONTROLLER 9
THE SILICON CONTROLLED RECTIFIER (SCR) 12
POTENTIAL CONTROL AND EXTERNAL IR DROP 13
GENERAL COMPONENT DESCRIPTION 14
INITIALENERGIZATION 16
REGULAR MAINTENANCE AND ADJUSTMENT 18
TROUBLESHOOTING 20
APPENDIX:
INCLUDES ELECTRICAL SCHEMATIC, RECTIFIER DATA SHEET, AND ANY
OTHER OPTIONAL INFORMATION

C.P. SENTINEL AUTOMATIC TYPE CATHODIC PROTECTION RECTIFIER MANUAL
INTEGRATED RECTIFIER TECHNOLOGIES, INC.
Doc #: APC0010
Rev. 3.0, November, 2004
Page 2 of 22
Copyright © IRT Integrated Rectifier Technologies Inc.
All rights reserved. Unauthorized copying and distribution prohibited by law.
The contents of this Manual are subject to change without notice

C.P. SENTINEL AUTOMATIC TYPE CATHODIC PROTECTION RECTIFIER MANUAL
INTEGRATED RECTIFIER TECHNOLOGIES, INC.
Doc #: APC0010
Rev. 3.0, November, 2004
Page 3 of 22
INTRODUCTION
Corrosion of underground structures (pipelines, well casings, etc.) is a process that occurs every
minute of every day. As such, continuous protection is required to effectively prevent damage that
could cost a company significantly in lost revenues, manpower, and equipment. The proper
selection, installation, and operation of a suitable corrosion prevention system can be crucial to
ensure that this costly damage does not occur. For well-coated structures, structures with small
surface areas, or where minimal Cathodic Protection is required, a “sacrificial” type corrosion
prevention system may be used. For poorly coated structures, structures with large surface
areas, or where a larger amount of Cathodic Protection is required, an “impressed current” type
corrosion prevention system is required. One key component of an impressed current corrosion
protection system is a Cathodic Protection rectifier. A rectifier is a device that is used to convert
“alternating current” (AC), as provided by the power utility, to “direct current” (DC), as is required
for Cathodic Protection. The rectifier should be selected based on the type of control required for
the specific application, the amount of Cathodic Protection required to provide effective
protection, and the reliability of operation in the subject environment. IRT Integrated Rectifier
Technologies, Inc. manufactures Cathodic Protection rectifiers that exceed industry standards for
superior corrosion prevention and, as such, an IRT rectifier unit is a smart investment for any
company.
IRT Integrated Rectifier Technologies, Inc. Cathodic Protection rectifiers and associated products
are designed by a knowledgeable engineering team with years of experience in the corrosion field
and manufactured by skilled technicians with a dedication to quality. The IRT units are designed
with superior components to provide a high quality, reliable rectifier with an economic cost for
your application. IRT maintains a large volume of in-stock components and sub-assemblies to
ensure that orders can be shipped to you in the shortest time frame possible.
IRT products are sold and serviced by leading corrosion prevention engineering companies
throughout North America and Internationally. These companies have superior expertise in the
corrosion industry and have the personnel to meet all of your corrosion prevention system
requirements including design, installation, and maintenance. IRT products are also available
through leading material supply companies throughout North America.
Rectifiers manufactured by IRT Integrated Rectifier Technologies, Inc. are guaranteed against
defects in design, workmanship, or material for a period of one year from the time of shipment
from our facility. Please refer to our warranty statement for further details.

C.P. SENTINEL AUTOMATIC TYPE CATHODIC PROTECTION RECTIFIER MANUAL
INTEGRATED RECTIFIER TECHNOLOGIES, INC.
Doc #: APC0010
Rev. 3.0, November, 2004
Page 4 of 22
DELIVERY INSPECTION
Although the rectifier unit may not be scheduled for immediate installation, we recommend that
it be thoroughly inspected, both externally and internally, upon receipt to ensure that no
damage has occurred during shipment. Please remember that although the outside of the
rectifier packaging may not show any signs of damage, there may be internal damage that will
not be apparent until the outer packaging is removed. Any damage, whether internal or
external, must be reported to the freight carrier immediately. If any damage has occurred
during shipment; an indication of this should made on the freight paperwork, the shipment
should then be accepted, and a claim filed with the freight carrier. Please ensure to retain the
original packaging that may indicate how the damage occurred.
If damage has occurred during shipment and repairs or a return to the factory is required,
please contact us, or your local IRT distributor, with the Serial Number and the Model Number
of the rectifier. This information is crucial for us to determine the rectifier unit in question and to
be able to provide suitable assistance. A Return Materials Authorization (RMA) number must
be obtained from the factory prior to return of any damaged rectifier units.
PRE-INSTALLATION STORAGE
If the rectifier unit is to be stored prior to installation, it is recommended that it be stored in a dry
area, preferably indoors. If the unit is to be stored outdoors for an extended period of time, it is
recommended that it be placed on a raised surface (pallet or platform) and covered with a
protective sheet or tarp to ensure the packaging does not deteriorate due to rain or snow.
Whether stored indoors or outdoors, the unit should be placed in an area where it is protected
from accidental damage from moving vehicles or equipment. Ensure that the rectifier unit is
transferred to and from the storage facility using proper handling techniques.

C.P. SENTINEL AUTOMATIC TYPE CATHODIC PROTECTION RECTIFIER MANUAL
INTEGRATED RECTIFIER TECHNOLOGIES, INC.
Doc #: APC0010
Rev. 3.0, November, 2004
Page 5 of 22
SAFETY PRACTICES
This symbol denotes a possible shock or electrical hazard.
DO NOT INSTALL, REMOVE, or REWIRE
THIS EQUIPMENT WITH POWER APPLIED!!
As Cathodic Protection rectifiers are connected to the AC utility power, electrical shock hazards
are present within the rectifier units. It is recommended that only qualified electronic or electrical
personnel operate and maintain these units and that those personnel familiarize themselves with
the areas of possible hazard within the unit. Following these practices can enhance the safety of
personnel.
1.) Prior to site maintenance or inspection, familiarize yourself with the rectifier and
conditions at the site.
2.) Prior to doing any maintenance or troubleshooting on a rectifier unit, familiarize
yourself with any possible hazard points within the unit by reviewing the electrical
schematic and the physical layout of the rectifier.
3.) Whenever possible, set the AC disconnect from the power utility to the “OFF” position
prior to starting any work on the rectifier unit. Even with the rectifier AC input circuit
breaker in the “OFF” position, hazardous voltages are still present at any terminals
connected to the rectifier AC input terminals. Always tag and lock out the disconnect
to ensure others do not energize it while you are completing the rectifier work.
4.) Prior to opening the rectifier enclosure door, lightly touch the back of your hand to the
enclosure latch. If you feel an electrical tingle, set the fused AC disconnect to the
“OFF” position and contact an electrician for assistance.
5.) When taking readings across the rectifier terminals, it is recommended to use only
one hand, if possible.

C.P. SENTINEL AUTOMATIC TYPE CATHODIC PROTECTION RECTIFIER MANUAL
INTEGRATED RECTIFIER TECHNOLOGIES, INC.
Doc #: APC0010
Rev. 3.0, November, 2004
Page 6 of 22
GENERAL INSTALLATION RECOMMENDATIONS
To ensure reliable, long-term operation of the Cathodic Protection rectifier, proper installation
of the unit is required. Though most installation sites differ, there are several key guidelines
that should be followed.
a) Prior to installation, check the connections (especially the electrical connections) on the
rectifier unit to ensure that nothing has become loose during shipment. It is also
recommended that if any scratches occur to the enclosure during installation, that
these points be touched-up to prevent corrosion on the enclosure.
b) Selecting the site of installation is a very important factor. The rectifier should be
installed in a location that is easily accessible by company personnel for regular
adjustment, monitoring, and maintenance. However, it should not be located in areas
where unauthorized personnel have easy access to the unit and may damage or
vandalize it (i.e. residential areas, playgrounds, farm yards, etc.). The convenient
access to AC power and the cathodic protection DC connections must also be
considered when choosing the rectifier location.
c) Proper ventilation and cooling of the rectifier unit is essential and must be considered
when choosing a suitable location. Air-cooled rectifiers are cooled by the natural
convection of cool air drawn into the bottom of the rectifier enclosure, passing over the
internal components, and the resultant warm air expelled from the top or sides of the
enclosure. Oil-cooled rectifiers are cooled by the natural circulation of oil from the
bottom to the top of the rectifier tank, over the internal components, and the resultant
heat is radiated from the upper walls of the rectifier tank. As such, when choosing the
installation site for the rectifier, adequate spacing should be allowed for around the
sides of the rectifier unit. The rectifier should not be located near sources of heat such
as exhaust vents, power generators, etc. If possible, place the rectifier unit in an area
where it will be shaded during the hottest part of the day. If the rectifier is to be installed
in an area with a high ambient temperature and minimal natural shading, a protective
sunshade is recommended.
d) The rectifier unit should be mounted on a secure surface. Ensure that the wall, pole,
frame, or mounting pad is designed to hold the full weight of the rectifier unit.
e) If the rectifier is to be installed in an area subject to frequent lightning activity,
upgraded, high-energy type surge arrestors are recommended. If possible, do not
locate the rectifier on a hill top where there increased chances of lightning strikes. Use
of a low resistance ground rod(s) is recommended. Locate the ground rods adjacent to,
but away from the rectifier, the ground bed, and incoming CP cables. Remember, most
damaging voltage surges are the result of induced pickup rather than a direct strike.
f) Do not install other equipment on or inside the rectifier enclosure without prior consent
from the factory. Unauthorized equipment installation will invalidate the rectifier
Warranty, as IRT has no control of the equipment added or the resultant detrimental
affect to proper rectifier cooling / operation.

C.P. SENTINEL AUTOMATIC TYPE CATHODIC PROTECTION RECTIFIER MANUAL
INTEGRATED RECTIFIER TECHNOLOGIES, INC.
Doc #: APC0010
Rev. 3.0, November, 2004
Page 7 of 22
RECTIFIER CONNECTIONS AT SITE
DO NOT INSTALL, REMOVE, or REWIRE
THIS EQUIPMENT WITH POWER APPLIED!!
After the rectifier has been installed in a suitable location, have a qualified electrician connect
the rectifier unit to the AC supply following local and national codes. Please note that most
electrical codes require a disconnect device between the AC power supply and the rectifier.
Ensure that for dual AC input rectifiers (115 / 230 or 230 / 460 VAC), that the AC input terminal
jumpers are properly configured for the actual AC input voltage being supplied and that the AC
input wires are connected to the correct AC input terminals.
The grounding rod(s) should be connected to the ground lug terminal adjacent to the AC input
terminals within the rectifier.
Next, connect the cable(s) from the anode bed to the RECTIFIER POSITIVE output lug
terminal(s) and the structure cable(s) to the RECTIFIER NEGATIVE output lug terminal(s).
Ensure that these cables are suitably sized for the expected current and the length of the
cable run. Also, it is absolutely imperative that the polarity of DC connections is correct. A
reversal of the DC cables can actually cause accelerated corrosion and eventually, severe
damage to the structure to be protected.
C.P. SENTINEL Automatic Potential Controlled Rectifiers require two additional connections
for proper operation, the Reference Electrode and the Structure Sensing leads. Connect the
Reference Electrode to the rectifier terminal marked “REFERENCE” (REF) and the Structure
Sensing lead to the terminal marked “STRUCTURE” (STR.). The Structure Sensing lead must
be a separate non-current carrying lead connected to the protected Structure, usually adjacent
the Reference Electrode.
APPLICATION NOTES:
1. Superior Potential Mode control is achieved by minimizing noise on the lead wires
used for the REFERENCE Electrode & STRUCTURE sensing. It is recommended that
lead lengths in excess of 25 feet or leads in noisy electrical environments be shielded
in a separate conduit, or consist of shielded, twisted-pair conductors installed using
recommended shielding practices.
2. C.P. SENTINEL Automatic Potential controlled rectifiers are equipped with “Loss-of-
Reference” shutdown feature. Upon degrading or failure of the Reference Electrode,
internal cell resistivity increases, and the voltage “reference” decreases. The natural
condition for an automatic potential rectifier is to increase to full output to counter the
reduced voltage sensed. This feature is designed to prevent structure coating failure
due to excessive polarization if this cell failure condition occurs. If this type of rectifier is
to be used in Current or Voltage Modes without a Reference Electrode attached, it will
be necessary to jumper the REFERENCE- STRUCTURE hook-up terminals of the
rectifier. The rectifier REFERENCE SELECT switch must be set to sense an active and
functional Reference Cell input, or no output will occur from the unit. A “Loss-of-
Reference” shutdown will be evident by the analog Potential Meter reading full scale or
if equipped with a digital Potential Meter reading overload; first digit a “1” followed by
remainin
g
di
g
its blank.

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.