Eaton EMR6-R400-A-2 Insulation Monitoring Relay
Brand: Eaton
Model: EMR6-R400-A-2
Introduction and Safety Warnings
This document provides technical information and operating instructions for the Eaton EMR6-R400-A-2 insulation monitoring relay.
Safety Warning: Electric current! Danger to life! Only skilled or instructed persons may carry out the operations described.
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Monitoring Functions
The EMR-R400-A-2 monitors insulation resistance according to IEC 61557-8 in unearthed IT AC systems, IT AC systems with galvanically connected DC circuits, or unearthed IT DC systems. It measures the insulation resistance between system lines and system earth. If this falls below adjustable threshold values, the output relays switch to the fault state.
Key Monitoring Capabilities:
- Insulation resistance monitoring in IT systems (AC, DC, AC/DC).
- Detection of inadmissible system leakage capacitance.
- Monitoring for incorrect settings that could cause faulty operation.
- Wire interruption detection (optional, configured via DIP switch).
Measured Input Voltage: 0-600 V DC or 0-400 V AC, 15-400 Hz.
The device can monitor control circuits (single-phase) and main circuits (3-phase).
Measuring Principle
The EMR-R400-A-2 uses a pulsating measuring signal to calculate insulation resistance. The signal's form changes based on insulation resistance and system leakage capacitance, allowing for prediction of insulation resistance changes. This method is also suitable for detecting symmetrical insulation faults.
Operating Principle
The system to be monitored is connected to terminals L+, L-. Earth potential is connected to terminals w and KE.
The device operates based on either the open-circuit principle (fault state: relay energized) or the closed-circuit principle (fault state: relay de-energized), depending on DIP switch settings.
After applying control supply voltage, the relay performs a system test routine including network diagnosis and setting verification. If no faults are detected, the output relays switch to the operational state.
Configurations:
- 1 x 2 c/o contacts: If the measured value drops below the set threshold, relays switch to fault state. They return to original state when the value exceeds the threshold plus hysteresis. Prewarning threshold (R2) has no influence.
- 2 x 1 c/o contact (prewarning and warning): If the measured value drops below the prewarning threshold, the second relay (21-22/24) switches. If it drops further below the warning threshold, the first relay (11-12/14) switches. Relays return to original state when values exceed thresholds plus hysteresis.
LEDs, Status Information, and Fault Messages
| Operational State | U: green LED | F: red LED | R: yellow LED |
|---|---|---|---|
| Start-up | OFF | OFF | |
| No fault | ON | OFF | -- 1) |
| Prewarning | ON | ON | ON 1) |
| Insulation fault (below threshold value) | ON | ON | ON 1) |
| w/KE wire interruption | ON | ON | ON 1) |
| L+/L- wire interruption during system start-up / test function | ON | ON | ON 1) |
| System leakage capacitance too high / invalid measurement result | ON | ON | ON 1) |
| Internal system fault | OFF | ON | ON 1) |
| Setting fault 2) | ON | ON | ON |
| Test function | ON | OFF | ON 1) |
| No fault after fault storage 3) | ON | OFF | ON 4) |
1) Depending on configuration.
2) Possible faulty setting: Threshold for warning is set higher than threshold for prewarning.
3) Device triggered after insulation fault. Fault stored, insulation resistance returned above threshold + hysteresis.
4) Depending on the fault.
Test Function
Test function is only possible when no fault is present. Pressing the front-face combined Test/Reset button executes a system test routine. Output relays switch to the fault state while the button is pressed, the control contact S1-S3 is closed, or test functions are processed.
Fault Storage, Reset Function
With fault storage active, output relays remain in the fault state. They return to their original state after the Test/Reset button is pressed or remote reset (S2-S3) is activated, provided insulation resistance is above the set threshold(s) plus hysteresis.
Fault storage is non-volatile (remanent). After power off and on, the device returns to its previous state until a reset is executed.
DIP Switch Functions
DIP switches are used for adjustment:
- 1: ON = Closed-circuit principle, OFF = Open-circuit principle
- 2: ON = Non-volatile fault storage ON, OFF = Non-volatile fault storage OFF
- 3: ON = Interrupted wire detection ON, OFF = Interrupted wire detection OFF
- 4: ON = 2 threshold values (2 x 1 c/o contact), OFF = 1 threshold value (1 x 2 c/o contacts)
(R2.x disabled)
Default setting: All DIP switches in position OFF.
Electrical Connection
- A1-A2: Control supply voltage Us
- L+, L-, KE, w: Measuring input
- 11-12/14: Output relay 1
- 21-22/24: Output relay 2
- VS, V1+, V1-: Connection for coupling unit EMR6-RC690
- S1, S2, S3: Control inputs, volt-free triggering
Technical Data
- Ambient temperature Ta during operation: -25 ... +60 °C (-13 ... +140 °F)
- Pollution degree: 3
- Degree of protection: housing IP50, terminals IP20
- Internal impedance Zi at 50 Hz: min. 155 kOhm
- Peak value of Um: 24 V +10 %
- Max. value of Im: 0.15 mA
- Max. system leakage capacitance Ce: 20 µF
- Max. DC voltage Ufg: 460 V DC
- Test voltage: supply circuit / output circuit 2.32 kV 50 Hz, 2 s; supply circuit / measuring circuit 2.32 kV 50 Hz, 2 s; measuring circuit / output circuit 2.53 kV 50 Hz, 1 s
- Min. switching voltage / current: 24 V / 10 mA
- Rated operational current Ie (IEC/EN 60947-5-1): AC-12 (resistive) 230 V 4 A; AC-15 (inductive) 230 V 3 A; DC-12 (resistive) 24 V 4 A; DC-13 (inductive) 24 V 2 A
- Internal resistance Ri of the measuring circuit: min. 185 kOhm
Function Diagrams
The document includes diagrams illustrating different operational modes:
- a) Insulation resistance monitoring without fault storage, auto reset, 1 x 2 c/o contacts: Shows system behavior with automatic reset and no fault memory.
- b) Insulation resistance monitoring with fault storage, manual reset, 1 x 2 c/o contacts: Shows system behavior with manual reset and fault memory enabled.
- c) Insulation resistance monitoring without fault storage, auto reset, 2 x 1 c/o contact: Similar to (a) but with two threshold levels (prewarning and warning).
- d) Insulation resistance monitoring with fault storage, manual reset, 2 x 1 c/o contact: Similar to (b) but with two threshold levels.
These diagrams depict the timing of control supply voltage (a), remote test (b), remote reset (c), measured value (d), hysteresis (e), threshold value (f), operating principles (g, m), output relays (h, i), and LED status indicators (j, k, l).
Wiring Diagrams
Various wiring diagrams are provided for different system configurations:
- 2-wire AC system
- 3-wire AC system
- 4-wire AC system
- 2-wire DC system
- 3-wire DC system
These diagrams illustrate the connections to terminals L+, L-, KE, w, A1, A2, S1, S2, S3, VS, V1+, V1- for different voltage types and system configurations. They also include notes on connecting L+ and L- to different conductors and using the EMR6-RC690 coupling unit for higher voltages.
Additional Information
cULus Approval: For use in Pollution Degree 2 Environment.
Minimum Distances: For continuous measured voltage > 400 V, lateral spacing to other units must be min. 10 mm (0.39 in).
