Woodward MRA1 Manual
Woodward MRA1 Manual

Woodward MRA1 Manual

Trip circuit supervision

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MRA1 – Trip Circuit Supervision
Manual MRA1 (Revision C)

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Summary of Contents for Woodward MRA1

  • Page 1 MRA1 – Trip Circuit Supervision Manual MRA1 (Revision C)
  • Page 2 Woodward Manual MRA1 Woodward reserves the right to update any portion of this publication at any time. Information provided by Woodward is believed to be correct and reliable. However, no responsibility is assumed by Woodward unless otherwise expressly undertaken. © Woodward 1994–2019...
  • Page 3: Table Of Contents

    Connecting the auxiliary voltage ..................14 Testing the supervision circuits ..................14 Testing the AUTO-RESET function .................. 15 Testing the external RESET inputs ................... 15 Testing the LED function ....................15 Technical Data .................... 16 Order form ....................18 DOK-TD-MRA1 Rev. C...
  • Page 4: Introduction And Application

    Woodward Manual MRA1 1. Introduction and application The MRA1 - relay of the HIGH TECH LINE is used to supervise the tripping circuit of protective de- vices taking into consideration the following protective criteria:  supervision of the auxiliary voltage for the tripping circuit and for the supply of protective devices ...
  • Page 5: Design

    Manual MRA1 Woodward 3. Design Connections Figure 3.1: Connection diagram MRA1 Version "A" Application with opener and shutter contacts of the circuit breaker Figure 3.2: Connection diagram MRA1 Version "B" Trip supervision with a shutter contact DOK-TD-MRA1 Rev. C...
  • Page 6: Coding Plug

    Switching thresholds of the input circuitry The MRA1 has a wide-range power pack for all commonly used voltage values. For this reason the pick-up thresh-olds of the internal relays K1, K2, K3 and the reset input must be adjusted to the existing rated voltage.
  • Page 7: Coding Of The Led Function

    Woodward Coding of the LED function The MRA1 can be used for two different monitoring concepts. Supervision of the circuit breaker by two supervision circuits. The opener and the shutter contacts of the circuit breaker are supervised separately. (P = parallel connection)
  • Page 8: Coding Auto/Manual Reset

    Manual MRA1 Coding Auto/Manual Reset Behind the front plate of the MRA1, on the bottom side, there is a coding plug for pre-setting the reset behavior of the output relay. If the coding plug is plugged in, the output relay and the indicator are set back if the fault, e.g. line break, has been corrected.
  • Page 9: Functions

    Relay K1 is in pick-up condition if the entire tripping circuit is in order. Cable break supervision The MRA1 can be used for two different monitoring concepts. Supervision of the circuit breaker by two supervision circuits. The opener and shutter contacts of the circuit breaker are supervised separately.
  • Page 10: Front Plate

    After approx. 400ms K2 and K1 will be released. The trip relay K1 is then in release position. (Refer to Figure 3.2) Front plate Figure 4.1: Front plate MRA1 DOK-TD-MRA1 Rev. C...
  • Page 11: Leds

    The status indicator or visual signal indicates, whether the MRA1 has tripped or not. Red means that the MRA1 has tripped. A dark display means that there is no fault. If the internal supply voltage of the device fails, the status indication will al-ways switch to the position released.
  • Page 12: Terminal Block

    Woodward Manual MRA1 Terminal block The plug-in module MRA1 has a very compact base with plug connectors and screw-type connect- ors:  8 screw-type terminals (connection plug row A) for voltage inputs  27 poles tab terminals for relay outputs, supply voltage etc. (terminal connectors series C, D and E, max.
  • Page 13 Figure 4.3: Dimensional drawing Please observe: A distance of 50 mm is necessary when the units are mounted one below the other for the front cover to be easily opened. The front cover can be opened downwards. DOK-TD-MRA1 Rev. C...
  • Page 14: Testing The Relay And Commissioning

    Testing the supervision circuits The MRA1 must be connected as shown in the test circuit diagram. Testing circuit MRA1 The coding plug for the LED function must be set to position "P" (refer to Chapter 3.3). The coding plug for the reset function should not be plugged in.
  • Page 15: Testing The Auto-Reset Function

    A2 and E9. The »OK« LED lights up and the indicator is reset. Testing the LED function The MRA1 has two possible ways of monitoring. For this reason there are two possible functioning methods for the LEDs »CB ON« and »CB OFF«. The coding plug is located on the upper side of the relay card (refer to chapter 3.3).
  • Page 16: Technical Data

    EN 60255-6, IEC 255-5: 5 kV; 1.2 / 50 s, 0.5 J High frequency interference test voltage, inputs and outputs between themselves and to the relay frame as per EN 60255-6, IEC 255-22-1: 2.5 kV / 1 MHz DOK-TD-MRA1 Rev. C...
  • Page 17 (“Harsh Environment Kit for High Tech Line Series”, separately available accessory, item number “HTLHEK”) IP54 by enclosure of the relay case and front plate (relay version D) Rear side terminals IP20 Vibration test: 0.5 g, 10 - 300 Hz DOK-TD-MRA1 Rev. C...
  • Page 18: Order Form

    Woodward Manual MRA1 7. Order form Trip circuit supervision MRA1- 19“- rack Housing (12 TE) Flush mounting DOK-TD-MRA1 Rev. C...
  • Page 19 Manual MRA1 Woodward Setting list MRA1 Project: Woodward-Job.-No.: Function group: = Location: + Relay code: - Relay function: Password: All settings must be checked at site and should the occasion arise, adjusted to the object/item to be protected. Device coding...
  • Page 20 Phone: +49 (0) 21 52 145 216 or 342  Telefax: +49 (0) 21 52 145 354 e-mail: salesEMEA_PGD@woodward.com Service Phone: +49 (0) 21 52 145 614  Telefax: +49 (0) 21 52 145 455 e-mail: SupportEMEA_PGD@woodward.com DOK-TD-MRA1 Rev. C...

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