ABB IRP Instruction Leaflet page 19

Directional Overcurrent Ground Relays
Types IRP, IRC and IRD
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2
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Figure 1: Type IRD Relay Without Case (Front View)
1) Instantaneous Overcurrent Unit and Saturating
Transformer
2) Current Polarized Directional Unit
3) Voltage Polarized Directional Unit.
4) Time Overcurrent Unit
5) Indicating Contactor Switches
6) Auxiliary Switch
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Sub 1
9664A15
Photo
Figure 2: Type IRD Relay without Case (Rear View)
1) Varistor
2) Saturating Transformer
3) "E" type Electromagnet
41-133S
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2
3
Sub 1
9664A16
Photo
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