Frequently asked questions
Do we have Type 2 Co-Ordination Chart for the LT47 overload relays?
FA332213
29 September 2021
LT47 is not an overload relay but an overcurrent relay, working on a definite time characteristic : current threshold and time based function.We do not have Coordination type 2 tables for LT47.
However, LT47 is an overcurrent relay. It performs a motor current measurement through its internal CT. So, LT47 doesn't add impedance to the motor control circuit and the coordination only results from the characteristics of the short circuit protection (fuses or circuit-breaker) and of the contactor. So the coordination tables we publish for LTMR can be used when LT47 is used.