ERICO PEC Series Potential Equalization Clamp - Manual (Page 2)

Purpose:
In communications and computer installations it is not uncommon to install separate ground systems
for lightning, mains power, computer (quiet ground), and communications (for security, and tempest
requirements). Although this approach may be desirable for certain operating reasons, when
lightning or other transient voltages occur, differences in ground potentials between the ground
electrodes are inevitable and equipment damage can result.
The Potential Equalization Clamp (PEC) is an isolation spark gap that is designed to help prevent
ground potential differences by operating under transient conditions to effectively clamp the grounds
together. Normally the PEC presents an effective open circuit. Once the ground potential difference
exceeds the breakdown voltage of the PEC, the circuit immediately closes and the ground potentials
are equalized. The PEC is fully resettable and has a life of over ten thousand operations.
Many buried pipelines are protected from corrosion by cathodic protection systems. To maintain the
insulation integrity of the pipe at metering and telemetry stations, insulating joints are inserted into
the pipe and those sections between insulating joints are grounded at the station. With long lengths
of pipelines, induced voltages in the pipe caused by local lightning or power line faults activity can be
in the order of tens of kilovolts. The result is that insulated joints failure is almost inevitable, with
flange type insulated joints particularly susceptible.
To help protect against insulated joint break-down, the PEC can be connected directly across the
joint. In its inactive state the PEC presents an effective open circuit across the joint. Should the
insulated joint voltage start to rise due to transients, the PEC will conduct and safely pass the
transient current to ground, limiting the voltage stress across the joint. After conduction the PEC will
automatically reset to its inactive state.
Installation:
· Installation and/or replacement of a PEC should only be carried out by qualified personnel
· The product must be installed in compliance with all national regulations and conditions
· The PEC may be damaged if exposed to lightning discharges in excess of rated values
· Unauthorized tampering or opening of the PEC is not permitted and invalidates the warranty
Markings:
CADDY, CADWELD, CRITEC, ERICO, ERITECH, ERIFLEX, and LENTON are registered trademarks of ERICO International Corporation.
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www.erico.com IP8108_A 2 OF 2
INSTRUCTION SHEET
Potential Equalization Clamp
(PEC Series)
©2013 ERICO International Corporation