The DOLD IL 5882.12/002 Series Type A Residual Current Monitor (German: Differenzstromwächter Typ A / English: Residual Current Monitor Type A - RCM) is a premier electrical measurement and preventive protection instrument belonging to the prestigious VARIMETER RCM family, researched and manufactured by E. DOLD & SÖHNE GmbH & Co. KG in Germany. In modern power management and automated facility operations, maintaining power supply continuity is of paramount importance across industrial processing plants, data centers, and commercial facilities. Unlike conventional residual current circuit breakers (such as ELCBs or RCCBs) that trip and disconnect electrical supplies instantaneously upon fault detection—causing immediate and expensive operational downtime—the DOLD IL 5882 continuously monitors system insulation resistance to earth in grounded networks in accordance with the international standard IEC/EN 62020. The device detects creeping insulation degradation at an early stage without disconnecting the mains supply, enabling plant operators to perform predictive maintenance before severe short circuits, arc flashes, or electrical fires develop.

Classified as a Type A device under IEC/TR 60755, the IL 5882 reliably measures both pure sinusoidal AC currents and pulsating DC residual currents across a broad operating frequency range of 20 Hz to 2000 Hz. The instrument operates in conjunction with external DOLD measuring current transformers, such as the solid-core ND 5016 and ND 5019 series or the split-core ND 5014 series (which allows effortless retrofitting into existing switchboards without dismantling heavy power cables). All active phase and neutral conductors of the monitored feeder are routed through the measuring transformer aperture (excluding the protective PE conductor). The internal high-performance electronics continuously compute the vector sum of currents; if insulation degradation occurs due to thermal aging, moisture, or mechanical wear, the resulting differential current is detected with a fast reaction time of 10 to 30 ms.

The defining characteristic of the ".12/002" variant lies in its contact arrangement: it is configured with two independent changeover contacts (2 C/O - 2 x 1 Wechsler) dedicated exclusively to the main Alarm tripping loop without pre-warning signaling (No Prewarning). This provides maximum flexibility for switchboard designs requiring two isolated alarm circuits upon threshold exceedance (e.g., transmitting remote status telemetry to a central PLC/SCADA system while concurrently triggering an audible/visual field siren or interlocking with a shunt trip coil). Furthermore, the device supports selectable manual or automatic reset via an external X1-X2 jumper link, integrated broken-wire detection between the relay and current transformer, and an adjustable response time delay of up to 5 seconds (tv = 0 - 5s) to suppress nuisance tripping caused by transient capacitive inrush currents during load switching.

This entry consolidates two distinct operational current models of the IL 5882.12/002 variant:
1. DOLD IL5882.12/002 ACDC24-230V 10A tv=5S: Features 9 selectable tripping values spanning from 10 mA up to 10 A (0.01A - 10A), optimized for standard industrial branch feeders, precision machine tools, and automated control cabinets.
2. DOLD IL5882.12/002 ACDC24-230V 30A tv=5S (Article Number: 0065519): Heavy-duty high-capacity variant featuring 9 selectable tripping thresholds from 10 mA up to 30 A (0.01A - 30A), engineered for main distribution switchboards, power substations, large motor assemblies, and installations with long cable runs characterized by elevated capacitive leakage currents.

The physical architecture of the IL 5882 is tailored to the DIN 43880 standard for modular distribution boards, featuring a shallow depth of 63 mm, a slim width of 35 mm (2 module widths / 2 TE), and terminal blocks positioned at the bottom of the enclosure to align flush alongside standard MCBs. The universal auxiliary power supply covers AC/DC 24-230V, interfacing seamlessly with global industrial control voltages. A transparent sealable front cover protects the rotary setting switches against accidental tampering, accompanied by front-panel Test and Reset pushbuttons. The DOLD IL 5882 is an indispensable residual current monitoring asset for electrical engineering contractors and modern automated industrial facilities worldwide.

• Manufacturer: DOLD (E. DOLD & SÖHNE GmbH & Co. KG)
• Country of Origin: Germany
• Product Series: VARIMETER RCM - IL 5882
• Technical Category: Type A Residual Current Monitor (Differenzstromwächter Typ A)
• Contact Code: .12/002 (Equipped with 2 changeover contacts 2 C/O for Alarm, without pre-warning)
• Residual Current Classification: Type A according to IEC/TR 60755 (AC and pulsating DC currents)
• Integrated Models in this Entry:
  - DOLD IL5882.12/002 ACDC24-230V 10A tv=5S (Measuring range: 10 mA ... 10 A)
  - DOLD IL5882.12/002 ACDC24-230V 30A tv=5S (Measuring range: 10 mA ... 30 A - Part Number: 0065519)
• Residual Current Setting Ranges:
  - 10A Model: 9 selectable tripping values: 10mA, 30mA, 100mA, 300mA, 500mA, 1A, 2A, 5A, 10A
  - 30A Model: 9 selectable tripping values: 10mA, 30mA, 100mA, 300mA, 1A, 3A, 5A, 10A, 30A
• Monitored Frequency Range: 20 ... 2000 Hz
• Auxiliary Operating Supply Voltage (UH): AC/DC 24 ... 230 V (50/60 Hz or DC)
• Auxiliary Voltage Tolerance: 0.85 ... 1.15 UH
• Power Consumption: Approx. 2.5 VA (AC) / 1.5 W (DC)
• Compatible External Current Transformers: DOLD external measuring CTs ND 5016, ND 5019 or split-core ND 5014
• Reaction Time: Fast response between 10 to 30 ms
• Response Delay Time (tv): Infinitely adjustable from 0 to 5 seconds (tv = 0 ... 5s)
• Fault Reset Mode: Selectable Auto-Reset or Manual-Reset via external X1-X2 bridge
• Integrated Safety Features: Broken wire detection for the measuring current transformer circuit
• Output Contact Configuration: 2 Independent changeover contacts (2 C/O - 2 x 1 Wechsler)
• Contact Switching Capacity: AC-15: 3A / AC 230V; DC-13: 2A / DC 24V (according to IEC/EN 60947-5-1)
• Continuous Thermal Current (Ith): Max. 5A
• Status LED Diagnostics: Green LED for auxiliary supply (ON), Red LED for alarm tripping status (Alarm)
• Integrated Pushbuttons: Front Test button (circuit functional verification) and Reset button (fault clear)
• Module Dimensions (W x H x D): 35 x 90 x 63 mm (Standard 2 TE modular width conforming to DIN 43880)
• Mounting Profile: Quick snap-on mounting on standard 35 mm DIN-rail (IEC/EN 60715)
• Terminal Architecture: Vibration-proof box clamp screw terminals positioned at the bottom of the housing
• Protection Degree: Housing IP40, Terminals IP20 (according to IEC/EN 60529)
• Ambient Operating Temperature: -20°C to +60°C
• Compliant Safety Standards: IEC/EN 62020, DIN 43880, IEC/EN 60947-5-1, CE
• Common Industrial Applications: Low-voltage distribution boards, water pump stations, air compressors, commercial buildings, hospitals, and automated production facilities