In redundant PIM modules, after a switchover, if the alarm for the reported channel still persists on the new primary, this most likely indicates a problem in the field wiring.
Taking electrical noise precautions
Electrical noise is composed of unabated electrical signals which produce undesirable effects in
measurements and control circuits.
Digital equipment is especially sensitive to the effects of electrical noise. Your recorder has built-in circuits
to reduce the effect of electrical noise from various sources. If there is a need to further reduce these
effects:
· Separate External Wiring - separate connecting wires into bundles (see Table 2-10) and route the
individual bundles through separate conduits or metal trays.
· Use Suppression Devices - for additional noise protection, you may want to add suppression devices at
the external source; appropriate suppression devices are commercially available.
REFERENCE
For additional noise information, refer to document number 51-52-05-01.
Electrical considerations
The recorder is considered “rack and panel mounted equipment” per EN 61010-1, Safety
Requirements for Electrical Equipment for Measurement, Control, and Laboratory Use, Part
1: General Requirements.
Recorder grounding
PROTECTIVE BONDING (grounding) of this recorder shall be in accordance with National
and local electrical codes.
Functional Earth
To minimize electrical noise and transients that may adversely affect the system,
supplementary bonding of the recorder enclosure to a functional earth ground, using a 3/4”
braided copper conductor, is required.
A terminal on the rear of the recorder is provided for this connection.
CE conformity special conditions (Europe)
Braid shielded cable is required for all Input I/O and Output Relay cables. All recorder cable shield wires,
except the RS485 Modbus communications cable shield, must be connected to a low impedance earth
ground at the recorder. This can be done by bussing the shields to an earth ground point, or by connecting
the shields to the conduit entry fittings if they are in electrical contact with the enclosure conductive
coating. In either case, the shields shall not extend into the recorder enclosure. The cable shields shall also
be connected to a low impedance earth ground at the farthest end of the cable, through a 0.0047 μF
capacitor. See each of the individual wiring diagrams.
