Protection of medium and low voltage motors requires use of multifunction protections with at least the following elements:

• A thermal image function
• A unit sensitive to the negative component of currents
• A unit allowing for quick elimination of all violent multiphase faults
• Units for too long start or locked rotor
• A function of start inhibition
• A unit for Max of zero sequence current

The choice between a unique (multifunction protection) or an combination of several protection systems (multifunction protection and additional protections) has to be done after a detailed study of the installation constraints, the start conditions and the thermal constant parameter for the motor to protect (its power alone is not a sufficient criteria to choose the type of protection).

Below the list of CEE products dedicated to the protection of motors.

	Device	Series	ANSI	Description
	NP M910	NP.900	50/51, 50N/51N, 50H/51H/68H, 46R/46L/46, 87N, 49M, 48/14, 66, 37, 51M, 50BF/52BF, 74TC, 86	Current based Motor Protection IED with IEC 61850 protocol
	NP M915	NP.900	50/51, 50N/51N, 67N, 50H/51H/68H, 46R/46L/46, 87N, 49M, 48/14, 66, 37, 55, 51M, 59, 27, 59P/27P/47, 59N, 81O/81U, 81R, 32/37/32R, 50BF/52BF, 60, 74TC, 86	Voltage & current based enhanced motor protection IED with IEC 61850 protocol
	NP T916	NP 900	87T, 87N, 49T, 50/51, 50N/51N, 50H/51H/68H, 46R/46L/46, 50BF/52BF, 49L, 74TC, 86	Differential protection IED with IEC 61850 protocol
	NP M800	NP.800	37I, 46, 48, 49, 5/49, 50, 50BF, 51LR, 51N, 66, 86, 74TC	Multi function motor protection
	NPM 800R NPM 800RE	NP.800 R	37I, 46, 48, 49, 5/49, 50, 50BF, 51LR, 51N, 66, 86, 74TC	Multi function motor protection
	NPW 800	NP.800	32, 37, 27, 59, 59N, 55, 81, 86, 74TC, BF	Multi function power, voltage and frequency protection
	NPW 800R	NP.800 R	32, 37, 27, 59, 59N, 55, 81, 86, 74TC, BF	Multi function power, voltage and frequency protection
	DMS 7001	PROCOM	87M	Digital differential protection relay
	IMM 7000	PROCOM	46, 49, 50, 51N, 51LR, 37, 66 (only 7990)	Multi function motor protection
	IMM 8000	PROCOM	49, 48, 51ST, 46, 50, 51N, 5/49, 5/66, 5/27+59, 51LR, 37, 27, 27ST, 27RC, 59, 86, 26 (only 8002)	Multi function motor protection with advanced functionalities
	DTM 7033	STATIC	87M	Differential protection relay
	GTM 7111	STATIC	55	Synchronous motor out-of-step protection relay
	IAG 7034	STATIC	87M	Three phase high impedance differential protection
	PTG 7000	STATIC	32, 37	Over and under power protection
	STEP 7000	STATIC	26	Temperature supervision relay
	TTE 7000	STATIC	64R	Rotor earth fault relay

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	Document	Lang.	Ref.	Index
	Solutions for motor protection	EN	--	--