Chapter N

Characteristics of particular sources and loads


Motor protection coordination

From Electrical Installation Guide

Type 1 and Type 2 coordination are defined in IEC 60947-4-1.

Total coordination is offered by some manufacturers.

Fig. N84 – Level of acceptable destruction according to the coordination types
Coordination Consequence of a short circuit Application field
Type 1 The contactor or starter shall cause no danger to persons and installation and may not be suitable for further service without repair and replacement of parts. General purpose application.

Basic machines.

Type 2 The contactor or starter shall cause no danger to persons or installation and shall be suitable for further use. The risk of contact welding is recognized, in which case the manufacturer shall indicate the measures to be taken as regards the maintenance of the equipment. Process with availability constraints, e.g.: continuous process, critical industrial machines.
Continuity of service(total coordination) No damage or maladjustment is permissible.

Must be able to restart immediately after fault is corrected No special precaution is required.

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