What is the replacement of the thermal overload relay of type LR5F1000 ?
The LR5F relays were used for the long start motor applications and have been discontinued for a long time.
Generally we recommend the use of LR9F** ( with class 20 selection ) for these applications , however the maximum range of the LR9F is limited to 630 A.
For 1000A rating, we suggest selecting LTMR08** (Tesys T) with external CT ( Protection class 5P15) with primary 1000A maximum and secondary selectable for 1A or 5A.
In similar cases , you can select external CTs + LRD relay ( LRD 05 for 1A Secondary ( setting range 0.63 to 1A) or LRD 10 for 5A secondary ( secondary range 4 to 6A)).