DSE 335 - A Rating of the Cts

Specifications
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2.6.1 V A RATING OF THE CTS
NOTE: Details for 4 mm² cables are shown for reference only. The connectors on the DSE
modules are only suitable for cables up to 2.5 mm².
The V A burden of the module on the CTs is 0.5 V A. However depending upon the type and length of
cabling between the CTs and the module, CTs with a greater V A rating than the module are required.
The distance between the CTs and the
measuring module must be calculated
and cross-referenced against the chart
opposite to find the V A burden of the
cable itself.
If the CTs are fitted within the
alternator top box, the star point
(common) of the CTs must be
connected to system ground (earth) as
close as possible to the CTs. This
minimises the length of cable used to
connect the CTs to the DSE module.
Example.
If 1.5 mm² cable is used and the
distance from the CT to the measuring
module is 20 m, then the burden of the
cable alone is approximately 15 V A.
As the burden of the DSE controller is
0.5 V A, then a CT with a rating of at
least 15 + 0.5 V = 15.5 V A must be
used.
If 2.5 mm² cables are used over the
same distance of 20 m, then the
burden of the cable on the CT is
approximately 7 V A. CT’s required in
this instance is at least 7.5 V A
(7 + 0.5).