Product Introduction
The DEIF AAL-111Q96/1 (Part Number 410839.40) is a specialized AC insulation monitoring device designed to continuously oversee the insulation resistance between an isolated (IT) network and the ship’s hull or earth. It is an essential safety instrument for marine and offshore power systems, providing early warning of potential ground faults before they lead to catastrophic failures or fire hazards. The Q96 designation refers to its standard 96×96 mm square DIN housing, making it compatible with most industrial and marine switchboard panels.
Product Specifications (Datasheet)
Dimensions: 96 mm x 96 mm x 75 mm Weight: 0.55 kg Country of Origin: Denmark Measuring Range: 0 to 1 MΩ (standard scale) Network Voltage: Up to 440V AC (direct connection) Auxiliary Supply: 110V, 230V, or 440V AC (model specific) Contact Output: 1 Changeover relay (SPDT) Contact Rating: 250V AC / 8A Operating Temperature: -25°C to +70°C Protection Rating: IP52 (Front), IP20 (Terminals) Approval: Marine type approved by major classification societies (DNV, LR, BV, ABS)
Application Fields
The DEIF AAL-111Q96/1 is primarily used in maritime environments, including:
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Marine Power Plants: Continuous monitoring of the main busbar on ships using insulated neutral systems.
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Offshore Platforms: Safety monitoring for drilling rig power distribution where “first fault” continuity is required.
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Emergency Switchboards: Ensuring the integrity of critical backup power circuits during crisis operations.
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Engine Rooms: Monitoring generator insulation levels to prevent winding damage from moisture or oil contamination.
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Tanker Vessels: Critical monitoring in hazardous areas where earth faults can pose an ignition risk.
Product Instructions
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Mounting: Install the unit in a 92×92 mm panel cutout. Secure it using the provided side clamps to ensure it withstands maritime vibrations.
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Wiring: Connect the measuring terminals to the AC lines and the earth terminal to the hull or common grounding point. Ensure the auxiliary power matches the voltage specified on the unit’s label.
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Setpoint Adjustment: Use the front-facing potentiometer to set the desired alarm threshold (typically 30kΩ to 100kΩ for marine applications).
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Testing: Periodically press the “Test” button on the front panel. This simulates an insulation fault to verify that the pointer moves and the alarm relay triggers.
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Reading the Scale: The logarithmic scale provides higher resolution at lower resistance values, allowing for precise monitoring of deteriorating insulation before it reaches a critical level.
Q&A – Frequently Asked Questions
Q: Can this monitor be used on DC networks? A: No, the AAL-111 series is specifically designed for AC networks. For DC systems, you would require the DEIF SIM or multi-line series designed for DC insulation monitoring.
Q: What does it mean if the pointer stays at infinity (∞)? A: This indicates that the insulation resistance is healthy and well above the maximum range of the scale. It is the normal operating state for a well-maintained system.
Q: Does the unit trip the circuit breaker automatically? A: Typically, no. It is usually wired to an alarm system to alert engineers. However, the relay contacts can be wired into a trip circuit if an automatic shutdown is required.
Q: Is this unit compatible with frequency converters? A: Standard AC monitors can sometimes be affected by harmonics. If your system has significant VFD interference, ensure you have the version with built-in harmonics filtering.
Similar Models Recommended
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DEIF AAL-111Q96/2
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DEIF AAL-211
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DEIF SIM-Q96
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BENDER ISOMETER IR420
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MEGACON KPM161N
