Figure 2.3: Rectifier Connection To Pipeline; Figure 2.4: Pcm Connection To Pipeline - SPX Radiodetection PCM+ Operation Manual

Transmitter to pipeline connections
Cathodic Protection Rectifier
Single rectifier providing impressed CP current to single
pipeline.
Rectifier is connected to anode and pipeline. Power
supply from 110/220V AC mains.

Figure 2.3: Rectifier connection to pipeline

Figure 2.4: PCM connection to pipeline

Disconnect both cables for pipeline and anode from the
rectifier terminals.
Failure to disconnect cables from rectifier will cause
unstable PCM signals, and may cause possible damage
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to the PCM transmitter.
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Connect the PCM transmitter to the cables, white
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lead to pipeline cable, green lead to anode cable.
Use the mains power supply for the transmitter.
If Isolation Joints are not used the PCM
present in both directions from the connection point.
Single rectifier providing impressed CP current to
multiple pipelines.
As above, disconnect pipeline and anode cables from
the rectifier.
Try to identify individual pipeline cables if they can be
separated at the rectifier, so that each pipeline can be
surveyed individually. This allows the maximum range
to be surveyed.
Connect the white PCM
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pipeline cables, and the green connection lead to the
anode cable. Use the PCM
cables to the individual pipelines.
If the PCM transmitter signal is applied to more than one
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pipeline at a time, the signal will be divided between them,
so the maximum range will be reduced.
Note: The pipe section which needs the most cathodic
protection current will also have the most PCM
so using the PCM Receiver to measure the current on
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all the pipe sections fed from the rectifier will indicate
the section with the worst CP faults. This is a quick and
easy guide to coating quality.
When a rectifier is not available
Test Points
At some test points there are Isolation Joints with cables
to the surface.
Connect the PCM transmitter across the isolation joint.
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Connect the white cable to the side of the pipeline that
you want to survey, and then the green cable to the other
side for the ground connection.
Note: Make sure that the pipes run in opposite
directions. If your connections are on pipes in the same
direction this may affect the survey results.
signal will be
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transmitter lead to one of the
receiver to help identify the
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PCM Operation Manual 5
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current,