Product Description

🔹 Earth Leakage Relay, 1Ph-2W / 3Ph-3W / 3Ph-4W, 110V AC – 7UG0841-1CB20

Product Description

The Siemens 7UG0841-1CB20 is a SIRIUS digital earth leakage monitoring relay designed to monitor earth leakage current in 1-phase 2-wire, 3-phase 3-wire and 3-phase 4-wire electrical systems. It operates with a 110 V AC supply and features a compact 35 mm module width, making it suitable for space-efficient electrical control panels. Siemens specifies the device with 2 × 1 changeover (CO) contacts for alarm, indication and control applications.

The relay is designed for use with a suitable core balance current transformer (CBCT) to detect residual or earth leakage current. Its digital monitoring function helps identify abnormal leakage conditions in industrial electrical systems and can provide a relay output when the configured leakage threshold is reached. Siemens specifies an adjustable earth leakage trip setting from 10 mA to 30 A, along with pre-warning functionality.

With its 110 V AC auxiliary supply, 2 CO outputs and 35 mm compact design, the 7UG0841-1CB20 is suitable for industrial automation panels, motor feeders, distribution systems, machine control panels and electrical monitoring applications.

Key Features

• Brand: Siemens

• Product Family: SIRIUS 7UG

• Part Number: 7UG0841-1CB20

• Product Type: Digital Earth Leakage Monitoring Relay

• Monitoring Function: Earth Leakage Monitoring

• System Compatibility: 1-Phase 2-Wire

• System Compatibility: 3-Phase 3-Wire

• System Compatibility: 3-Phase 4-Wire

• Supply Voltage: 110 V AC

• Output Contacts: 2 × 1 CO

• Contact Configuration: Changeover Contacts

• Module Width: 35 mm

• Earth Leakage Trip Setting: 10 mA to 30 A

• Pre-Warning: Available

• CBCT-Based Monitoring: Yes

• Reset: Automatic / Manual / Remote

• Application: Earth Leakage Monitoring

• Mounting: Control Panel / DIN-Rail Applications

• Standards: IEC 60947-4-1 and IEC 60947-5-1

Applications

The Siemens 7UG0841-1CB20 digital earth leakage relay can be used for:

• Earth leakage monitoring

• Earth fault monitoring

• Residual current monitoring

• Industrial electrical panels

• Motor control panels

• Power distribution systems

• Distribution boards

• Industrial automation systems

• Machine control cabinets

• Motor feeders

• Transformer feeders

• Generator systems

• Pump control panels

• Factory automation equipment

• Electrical maintenance systems

• Industrial machinery

• Power monitoring applications

• Electrical protection systems

Benefits

• Digital earth leakage monitoring

• Supports 1-phase 2-wire systems

• Supports 3-phase 3-wire systems

• Supports 3-phase 4-wire systems

• 110 V AC supply voltage

• Compact 35 mm module design

• Two changeover output contacts

• Wide earth leakage trip setting range

• 10 mA to 30 A adjustable trip setting

• Pre-warning function

• CBCT-based residual current detection

• Suitable for industrial electrical systems

• Helps identify abnormal leakage current

• Suitable for alarm and control circuits

• Supports automatic, manual and remote reset

• Space-saving installation

• Suitable for OEM and maintenance applications

• Genuine Siemens SIRIUS monitoring relay

Working Principle

The 7UG0841-1CB20 works with a compatible core balance current transformer (CBCT). The conductors of the monitored circuit pass through the CBCT, allowing the device to detect residual current caused by leakage to earth.

For a 3-phase 3-wire system, the three phase conductors are monitored through the CBCT. For a 3-phase 4-wire system, the three phases and neutral are included in the sensing arrangement. This allows the relay to detect an imbalance associated with earth leakage.

The relay provides configurable monitoring and relay outputs so that an external alarm, contactor, breaker or control system can respond to detected leakage conditions.

High-Level SEO Keywords

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Frequently Asked Questions

Q1. What is Siemens 7UG0841-1CB20?
The 7UG0841-1CB20 is a Siemens SIRIUS digital earth leakage monitoring relay used to monitor residual/earth leakage current in electrical systems.

Q2. Which electrical systems are supported?
It supports 1-phase 2-wire, 3-phase 3-wire and 3-phase 4-wire systems.

Q3. What is the supply voltage of 7UG0841-1CB20?
The relay is designed for a 110 V AC supply.

Q4. How many output contacts does the relay have?
It provides 2 × 1 CO, meaning two changeover contacts.

Q5. What is the module width?
The relay has a compact 35 mm module width.

Q6. What is the earth leakage trip setting range?
The earth leakage/fault trip setting is adjustable from 10 mA to 30 A.

Q7. Does the relay require a CBCT?
Yes. The earth leakage monitoring function uses a suitable core balance current transformer (CBCT) to detect residual current.

Q8. Does 7UG0841-1CB20 provide pre-warning?
Yes. Siemens specifies a pre-warning function for the earth leakage monitoring relay family.

Q9. Where is Siemens 7UG0841-1CB20 used?
It is suitable for industrial control panels, motor feeders, distribution systems, automation panels, machine control systems and electrical monitoring applications.

Q10. Is 7UG0841-1CB20 a circuit breaker?
No. It is a digital earth leakage monitoring relay. It detects leakage conditions and provides relay outputs for external alarm, control or protection equipment.