Catalog CR Magnetics Transducers, Relays, Transformers, Indicators (CR Magnetics) - 6
| Manufacturer | CR Magnetics |
| Description | Selection Guide |
| Pages / Page | 38 / 6 — Current Transformer Ratios. Changing Current Transformer Ratios. ACTUAL. … |
| File Format / Size | PDF / 1.6 Mb |
| Document Language | English |
Current Transformer Ratios. Changing Current Transformer Ratios. ACTUAL. TURNS. RATIO. Examples. WHERE:
Model Line for this Datasheet
Text Version of Document
Current Transformer Ratios Changing Current Transformer Ratios
The actual current ratio may be changed from the nameplate ratio by wrapping the primary and/or secondary leads through the window opening.
-
Wire from X1 terminal is routed through NUMBER OF SECONDARY TURNS
ACTUAL
NAMEPLATE RATIO ± THROUGH WINDOW OPENING the H1 side
TURNS
=
+
Wire from X1 terminal is routed through
RATIO
NUMBER OF PRIMARY TURNS the side opposite the H1 side (H2 side) THROUGH WINDOW OPENING
Examples
This illustration shows how a current transformer with a nameplate turns ratio of 125:5 can be rescaled to operate as a non-standard 55:5 ratio transformer.
WHERE:
Nameplate ratio = 125 (125/5) Number of secondary turns through window = - 3 Use -3 because the secondary wire is routed from the X1 terminal first through the H1 side. Use + if the wire was routed first through the side opposite the H1 side. Number of primary turns through window = 2 125
—
3 5 11 = 2 SECONDARY (5 AAC) TURNS RATIO = 11:1 CURRENT RATIO = 55:5 PRIMARY (55 AAC) X2 Black X1 This illustration shows the internal construction of a White current transformer. The outside face of the trans- former is identified as H1. The opposite face is iden- H1 tified as H2. The secondary leads are identified as X1 and X2. Current flowing out of terminal X1 will have the same polarity as current flowing into terminal H1.
Internet Resources http://www.crmagnetics.com/
• Transducer Selection Guide: transducer.html • Application Sheet: pdf/ancrct-1.pdf error.html appguide.html Heaters Controls And Sensors Ltd., www.hcs77.com Toll Free: 800 - 279 - 9912 5
The actual current ratio may be changed from the nameplate ratio by wrapping the primary and/or secondary leads through the window opening.
-
Wire from X1 terminal is routed through NUMBER OF SECONDARY TURNS
ACTUAL
NAMEPLATE RATIO ± THROUGH WINDOW OPENING the H1 side
TURNS
=
+
Wire from X1 terminal is routed through
RATIO
NUMBER OF PRIMARY TURNS the side opposite the H1 side (H2 side) THROUGH WINDOW OPENING
Examples
This illustration shows how a current transformer with a nameplate turns ratio of 125:5 can be rescaled to operate as a non-standard 55:5 ratio transformer.
WHERE:
Nameplate ratio = 125 (125/5) Number of secondary turns through window = - 3 Use -3 because the secondary wire is routed from the X1 terminal first through the H1 side. Use + if the wire was routed first through the side opposite the H1 side. Number of primary turns through window = 2 125
—
3 5 11 = 2 SECONDARY (5 AAC) TURNS RATIO = 11:1 CURRENT RATIO = 55:5 PRIMARY (55 AAC) X2 Black X1 This illustration shows the internal construction of a White current transformer. The outside face of the trans- former is identified as H1. The opposite face is iden- H1 tified as H2. The secondary leads are identified as X1 and X2. Current flowing out of terminal X1 will have the same polarity as current flowing into terminal H1.
Internet Resources http://www.crmagnetics.com/
• Transducer Selection Guide: transducer.html • Application Sheet: pdf/ancrct-1.pdf error.html appguide.html Heaters Controls And Sensors Ltd., www.hcs77.com Toll Free: 800 - 279 - 9912 5
