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...
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 ...
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...
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.
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)
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.
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.
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...
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.
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.
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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...
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.
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).
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...
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(“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...
Woodward Manual MRA1 7. Order form Trip circuit supervision MRA1- 19“- rack Housing (12 TE) Flush mounting DOK-TD-MRA1 Rev. C...
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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...
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