Parker E-DC, Hardware Installation Manual

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54 E-DC Hardware Installation Guide Appendix B – EMC Installation Guide
and are suitable for use with cable having an outside diameter up to 10 – 13mm.
The specification is as follows:
Chomerics part number 83-10-M248-1000 83-10-M637-1000
Outside diameter 17.5mm (0.69 in.) 28.5mm (1.12 in.)
Inside diameter 9.5mm (0.375 in.) 13.77mm (0.54 in.)
Length 28.5mm (1.12 in.) 28.57mm (1.13 in.)
Impedance at 25MHz 115
Ω
158
Ω
Impedance at 100MHz 170
Ω
250
Ω
Curie temperature 130
°
C 130
°
C
(
the device should not be operated near this temperature)
Handling and Installing the Ferrite Absorbers
Take care when handling the absorbers—they can shatter if dropped on a hard
surface. For this reason the suggested method of installation is to use a short length
of heat-shrink sleeving, as shown below. This gives a degree of physical protection
while the cable is being installed. The sleeving should have a shrink ratio of at
least 2.5:1. Cable ties may be used as an alternative; however, they give no
physical protection to the absorber.
Ferrite absorber
retained by
heatshrink sleeving
Ferrite Sleeve Installation
R-Clamp Installation Details
The function of the R-clamp is to provide a 360 degree metallic contact and thus a
convenient means of ensuring a proper radio frequency ground. When dealing with
electromagnetic interference issues, it is important to remember that continuity—a
DC connection—does not at all speak to the integrity of an AC (high-frequency)
bond. High-frequency bonding typically involves wide, flat cabling to establish a
suitable system ground. When applied properly, the R-clamp has been shown to
give an adequate high-frequency contact.
When installing an R-clamp, as shown in the next figure, install it as close to the
cable end as possible. Mount the R-clamp to a suitable ground, backplane, earth
stud or bus bar—this may require removing paint from a cabinet or panel.
Remove only the outer (vinyl) jacket of the braided screen cable; this allows the
braid to continue to the cable connector. Be careful not to damage the braid. Snap
the R-clamp over the exposed braid, and adjust for a tight fit. Secure the clip to the
designated ground with a machine screw and lock washer. The use of brass or
other inert conductive metal R-clamp is recommended. Cover any exposed bare
metal with petroleum jelly to resist corrosion.
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