MiCOM P211 Three-phase LV Motor Protection Relay MiCOM P211 Three-phase LV Motor Protection Relay MiCOM P211 Three-phase LV motor protection relay Introduction Benefits Electric motors in drive systems are subject to various disturbances and faults, caused by abnormal electrical, mechanical or thermal conditions. • Measurement of true RMS current value MiCOM P211 is designed to protect motors against: • Overload protection to operate according to inverse time characteristics • overloads • underloads • short-circuits • supply unbalance • loss of phase • excessive temperature inside the motor The relay protects three-phase LV motors of nominal supply voltage up to 1000 V, powered directly from the network or through frequency converters to drive pumps, vents, mills, fans, crushers, compressors, conveyors, etc. • Overload protection within wide range of current and frequency • Protection against short-circuit faults (e.g. rotor stall) • Adjustable underload protection (e.g. no-load running) with time delay setting • Possibility to widen the relay current range downwards, by multiple interleaves of motor feeders through guiding channels in the relay housing • Possibility to widen the relay current range upwards by means of external current transfomers • Wide range of underload time settings to enable the relay adjustment to duration of motor start up phase • Tripping time cut down when a motor gets hot due to phase currents increase • Adjustable unbalance and loss of phase protection with delay setting Fig.1: MiCOM P211 • The keyboard and 4-digit LED display to enable programming of the relay and reading of: phase currents, thermal state of motor, the max. current and duration of most recent motor start-up phase and relay settings entered • Easy and convenient motor feeders connection to the relay by their interleaving through the three guiding channels in the housing. This ensures galvanic separation of the electronic circuits of the relay from the motor feeders • Pre-fault indication of overload condition, when the set threshold is overreached by 10% • Over-temperature protection to co-operate with PTC sensors • LEDs to indicate motor state and corresponding to the individual protection features • Two output relays, programmed independently and corresponding to the protection feature, as decided by a user • Non-volatile memory of settings and all protection feature states in case of the auxiliary voltage interruption • Self-reset or reset of overload and temperature protection after tripping, either manually from the keyboard or remotely by means of an external command contact • Setting tamper proof feature by means of a password or a transparent plastic cover for the front panel 2 Functions P 211 Overload protection MiCOM P211 protects a motor against a failure caused by overcurrent conditions above the user-defined threshold. The IB base current setting should be equal to the motor rated current In, unless otherwise recommended by a manufacturer (refers to motors used in intermittent duty operations). If motor current exceeds the value of 1.1 x IB the overload LED indicator starts to blink. The thermal image feature trips the motor when thermal state has reached 100% and then the LED indicator lights on continuously. The tripping time corresponds to an inverse time characteristic, which is chosen by selecting an overload time setting. The motor thermal state is calculated on basis of actual current value. There are 40 time settings available, ranging from 1 to 40 s with 1 s increments. Time settings are defined for I = 6 x IB in a cold motor state. Fig. 2: Front panel of MiCOM P211 1 2 3 4 5 6 - keyboard - LED display - I> overreach and I>T trip indicator - I>> short circuit fault trip indicator - I< underreach and I<T trip indicator - indicator of unbalance or loss of phase presence © and trip ©T 7 - indicator of excessive temperature inside the motor 8 - auxiliary power supply terminals 9 - output contact terminals: 13 - 14: P1 relay 23 - 24: P2 relay 10 - PTC sensor terminals 11 - control input terminals Short circuit faults Output relays performance If there is a must of running an overheated motor (eg. to prevent from technological process downtime), the motor thermal state may be reset by means of the relay keyboard. MiCOM P211 protects against short circuit faults (eg. rotor stall). If the fault current exceeds the set threshold relay will trip the motor within 0.1s. Underload Over temperature motor protection State of P1 and P2 output relays depends on : • presence or absence of auxiliary supply voltage Vx • user-defined programme of operation • state of S1- S2 control input • status of individual protection features It prevents a motor from no-load running. A drop of current below the set threshold will make the motor trip after the set period of time. Unbalance and loss of phase If an unbalance condition overreaches the set threshold or there is a loss of phase in the system the relay trips after the set period of time has expired. The unbalance condition is calculated according to the following formula: Iaverage = IL1 + IL2+ IL3 3 MiCOM P211 will trip a motor if temperature inside its windings makes the total resistance of PTC sensors connected in series exceed 3900 Ω. Restarting the motor will only be possible after the windings temperature has dropped below the corresponding value of total PTC resistance of 1900 Ω. If the connection between the sensors and the relay is broken MiCOM P211 will immediately trip the motor and prevent from restarting until the connection is restored. If the over temperature protection is not used, T1-T2 teminals must be shorted. 3 Auxiliary supply voltage Vx If the relay is not powered the two output relays P1 and P2 are in their reset position (contacts open). Applying the supply voltage to A1A2 terminals will make the output relays perform according to a userdefined programme and the status of individual protection features of the relay. If any protection feature trips a motor and then the supply voltage is interrupted for a while, the relay operation depends on a user-defined scheme: • relay memory is reset (self-reset), • status of protection features before the supply interruption is memorised (manual reset is needed). S1 - S2 control input Monitoring and metering Reset of protections tripped Performance of S1-S2 control input should be defined from the keyboard on front panel (Fig. 2). There are 4 options available: During the relay operation the following information can be read from LED front panel display (chosen from the keyboard): Reset of any protection tripped may only be performed after cause of the tripping has ceased. Reset may be done manually or automatically. • any protection feature started does not make the output relay P1 operate, as long as S1-S2 terminals are shorted • true RMS phase current: phase L1 - L1 indicator is on phase L2 - L2 indicator is on phase L3 - L3 indicator is on • Manual reset: - by means of the keyboard, - by shorting S1-S2 input. • all tripped protection features are reset by shorting S1-S2 input, providing the cause of faults has ceased • motor thermal state [%]: [%] indicator is on • immediate motor trip by shorting S1-S2 input • max. current [A] during the most recent start up phase: L1, L2, L3 indicators are on • Self-reset: - option available only for overload (I>T) and temperature (PTC) protection, if chosen by the user. • the output relay P2 is changedover, if S1- S2 are shorted • duration of the most recent start up phase [s]: [s] indicator is on Setting the relay Protection states Light indication Motors with rated current of 4 - 80A Description of protection indicators concern the state of S1-S2 terminals being opened. The following thresholds should be set by means of the keyboard: Protection status Protection Symbol Trip Start Overload I> I>T Short-circuit - I>> Underload I< I<T Unbalance Loss of phase © Zf ©T ZfT Temperature - PTC Stand-by indication On applying supply voltage Vx: Output relays performance • LED indicators I>, I>>, I<, © and PTC go on for a short instant of time Performance of each output relay contact (NO) may be programmed, according to the tables below. • symbol RPx.0 is shown on the display for 1 s (where “x” stands for software version) P1 output relay Supply voltage Vx not applied applied applied applied Protection Protection P1 tripped status started - - open - - close I>, I<, ©, Zf - I>T,I<T, ©T, ZfT close close open Any combination of tripped protection and P1 status is possible. P2 output relay Vx Start, trip or reset P2 status not applied - open applied - applied I>, I<, ©, Zf, I>T,I<T,©T, ZfT applied reset open close no change change no change change • L1 indicator goes on and symbol 0.0 is shown on the display. Indication of protection status LED indicator Protection status Blinking ON I> I>T I>> I< I<T I> I< - © ©T Zf ZfT PTC © - I> I>> I< - © - © © PTC Indication of power supply interruption All LED indicators are off. Any combination of start/trip/reset and P2 status may be chosen. 4 • Overload protection I>: - IB base current value equal to motor rated current - tripping time for t=6×IB (depending on duration of motor start up phase ) • Short-circuit protection I>>: - current tripping threshold equal to a multiple of IB • Underload protection I<: - current value as a percentage of IB - tripping time [s] • Phase unbalance protection: - unbalance value [%] - tripping time [s] • Loss of phase protection: - tripping time [s] • Temperature protection: - PTC sensors connected in series should be connected to T1-T2 terminals (if PTC are not available T1-T2 must be shorted). Motors with rated current In<4 A L3 L2 In such a case it is necessary to repeatedly interleave the motor phase feeders through guiding channels in the relay housing. The number of phase wire interleaves must be the same for each phase. IB current should then be equal: IB = In × (number of interleaves). The current and time settings as specified before. L1 L1 N 13 14 13 24 23 A2 A1 M 3 s 14 MiCOM P211 +t PTC T1 T2 Motors with rated current In>80 A It is recommended to use MiCOM P211 version of In = 4-6A and three external CT's with their secondary current of 5A. The transformers should be designed for protection applications (not instrumentation). The high accuracy class of the CT’s is not recommended, since in case of short circuit faults their cores get saturated and significant portion of fault current is not transformed to the secondary circuit. The IB current setting should be calculated using the following formula: Fig. 3: Connection diagram for direct start up application N U2 V2 A2 A1 24 23 14 13 U1 3~ W2 M L1 MiCOM P211 V1 W1 T2 L2 T1 L3 IB = 5 × In / I1p where: In - motor rated current, I1p - primary current of a CT with secondary current of 5 A. The current and time settings are defined as specified before. Fig. 4: Example of MiCOM P211 application in star-delta arrangement IB=In When CT's with the secondary current of 1A are used, then each of their secondary phase wires should be interleaved 5 times through the respective channel in the relay housing. The settings - as specified before. L1 N Caution: In star-delta arrangement (Fig. 5) IB current should equal: U2 V2 IB = 0.58 x In A2 A1 24 23 14 13 S U1 3~ W2 M V1 W1 C L1 MiCOM P211 L3 T2 T1 Programming the relay Performance of P1 and P2 output relays and S1-S2 control input should be selected from the keyboard. Fig. 5: Example of MiCOM P211 application in star-delta arrangement IB=0.58 x In 5 L2 Fig. 6: Examples of inverse-time characteristics, for Tn=10s and thermal states of the motor: Q=10%, 50% and 90% Mounting Fig. 7: MiCOM P211 connection for motor currents IBmin < In < IBmax. Fig. 8: MiCOM P211 connection for motor currents In < IBmin. 111.0 103.0 32.5 5.0 10.5 23.0 23.0 Fig. 9: Dimensions of MiCOM P211 6 MiCOM P211 is mounted on 35 mm DIN rail. The motor phase feeders or the wires of CT secondary circuits are interleaved through the guiding channels in the housing (Fig. 7 or 8). The rest of connection wires, i.e. auxiliary power supply, output relays, control input and PTC sensors are connected to the screw terminals, located in the bottom part of the front panel (Fig. 2). Auxiliary power supply is connected to A1 - A2 terminals. Output circuits should be connected to terminals 13-14 and 23-24. PTC sensors should be connected to T1-T2 terminals. If they are not used T1-T2 must be shorted. NO contact should be connected to S1-S2 terminals, if the control input is to be used. Otherwise S1-S2 terminals should remain opened. Technical data IB base current settings 4 - 6 A in steps of 0.2 A 5 - 10 A in steps of 0.5 A 10 - 20 A in steps of 0.5 A 20 - 40 A in steps of 1 A 40 - 80 A in steps of 1 A Frequency range Contacts rating • overcurrent at I=6 x IB • make, carry: 5A • break: 5 A (220 V ac, cos ϕ ≥ 0.4) 1 - 40 s, in steps of 1 s • undercurrent module Mechanical life 0 - 60 s, in steps of 1 s 107 • asymmetry module Electrical life 0 - 25 s, in steps of 0.1 s 105 • loss of phase module 10 - 1000 Hz Current accuracy index 10 % Protection setting ranges • short circuit Insulation withstand 0 - 10 s, in steps of 0.1 s • circuit-circuit PTC sensor input • max. resistance in cold state 2 kV, 50 Hz (1 min) 1500 W • contact gap • tripping resistance (5 - 12) x IB 1 kV, 50 Hz (1 min) 3700 - 3900 W • undercurrent Temperature • resetting resistance • ambient 1900 - 2100 W 30 - 90 % of IB • tripping time • unbalance 15 - 50 %, in steps of 1 % • tripping time Time setting ranges <0.1 s Time accuracy index 10 % Output contacts 2 N/O (programmed independently) - 5 0C - + 55 0C <0.1 s • storage Supply voltage options - 25 0C - + 70 0C 24, 110/127, 230 V 50/60 Hz, 24 - 230 V ac/dc Protection class Supply voltage tolerance (0.8 - 1.1) Vx • housing IP 40 • terminals IP 20 Burden Weight ~ 3 VA 0.5 kg Information required with order MiCOM P211 Relay type 8 0 3 . 0 0 0 . 0 0 . 1 IB base current 1 2 3 4 5 4-6A 5 - 10 A 10 - 20 A 20 - 40 A 40 - 80 A Auxiliary supply voltage Vx 1 2 3 4 24 V ac 110/127 V ac 230 V ac 24 - 230 V ac/dc Your contact: ALSTOM T&D Protection & Control SA Strzegomska 23/27, 58-160 Swiebodzice, Poland Sales Dept. Tel.: +48 (74) 854 84 25 • Fax: +48 (74) 854 85 48 www.alstom.com • e-mail: pcb-gee.poland@tde.alstom.com 7 T R A N S M I S S I O N & D I S T R I B U T I O N Protection & Control, HQ, 60 Route de Sartrouville, BP58, F78230 Le Pecq Cedex. France Tel: +33 (0) 134 80 79 00 Fax: +33 (0) 134 80 79 13 Email: protection.control@tde.alstom.com Internet: www.tde.alstom.com © 2000 ALSTOM. ALSTOM, the ALSTOM logo and any alternative version thereof are trademarks and service marks of ALSTOM. Other names mentioned, registered or not, are the property of their respective companies. Our policy is one of continuous development. Accordingly the design of our products may change at any time. Whilst every effort is made to produce up to date literature, this brochure should only be regarded as a guide and is intended for information purposes only. Its contents do not constitute an offer for sale or advice on the application of any product referred to in it. We cannot be held responsible for any reliance on any decisions taken on its contents without specific advice. Publication: REF-LV-803-K-01-GB Printed in Poland.
