ABB RELION 615 Series Installation Manual page 73

1MRS756375 T
• To exchange a protection relay to a different unit, change the case and connect
the wires.
• When replacing only the plug-in unit for maximum system availability, check that
the order number of the case and the spare plug-in unit are equal to ensure the
type compatibility.
The serial numbers of the original case and the spare plug-in unit are temporarily
mismatched. For matching the serial numbers, replace also the case of the spare
unit as soon as possible, for example, during the next scheduled maintenance
break.
615 series
Installation Manual
Removing, repairing and exchanging
73