MCIL21M 21-Pin Male Inline Underwater Connector – SubConn Compatible | HYSF SUBSEA

MCIL21M 21-Pin Male Inline Underwater Connector for Deep-Sea Applications

Les MCIL21M 21-pin male inline underwater connector from HYSF SUBSEA is a high-density electrical connector designed to provide reliable multi-circuit connectivity in demanding marine and subsea environments.Featuring 21 male electrical contacts, a durable neoprene rubber body, and a compact Micro Circular interface, the MCIL21M is suitable for applications requiring multiple electrical connections within a single underwater cable assembly.The connector is widely applicable to remotely operated vehicles (ROVs), autonomous underwater vehicles (AUVs), oceanographic research equipment, underwater sensor networks, marine monitoring systems, and offshore instrumentation.As part of the HYSF SUBSEA Micro Circular connector series, the MCIL21M is designed for operation in underwater environments with pressure conditions reaching approximately 60 MPa, equivalent to 6,000 meters of seawater, when used in a properly configured and qualified assembly.The MCIL21M is designed to mate with corresponding 21-pin female Micro Circular connectors, including the MCBH21F female bulkhead connector and MCIL21F female inline connector.Supplied with a standard 1-meter cable, the MCIL21M can also be configured with customized cable lengths and wiring arrangements to meet the requirements of different underwater equipment projects.

Key Features of the MCIL21M Underwater Connector

The MCIL21M combines a high contact count with a compact mechanical structure suitable for demanding subsea installations.Key features include:

• 21-pin male configuration: Provides 21 individual electrical contacts for multi-circuit underwater connections.
• Micro Circular connector design: Suitable for subsea equipment requiring high-density electrical interfaces.
• Wet-mateable construction: Supports underwater mating and unmating under appropriate operating conditions.
• Deep-sea pressure capability: Designed as part of a connector series rated for approximately 6,000 meters of seawater depth.
• Durable neoprene rubber body: Provides flexibility and resistance to marine environmental conditions.
• Gold-plated electrical contacts: Helps maintain stable contact resistance and reliable electrical connections.
• SubConn-compatible interface: Designed for corresponding SubConn-style Micro Circular connector configurations.
• Standard 1-meter cable: Provides convenient integration into underwater electrical systems.
• Custom cable lengths: Supports OEM projects requiring specific installation dimensions.
• Multi-signal connectivity: Suitable for multiple independent control, monitoring, and instrumentation circuits.
• Compatible connector options: Can be paired with corresponding female bulkhead and inline connectors.

These features make the MCIL21M a practical choice for engineers searching for a 21-pin male underwater cable connector for ROVs, AUVs, and subsea sensors.

MCIL21M Technical Specifications

Paramètres	Specification
Brand	HYSF SUBSEA
Model Number	MCIL21M
Connector Series	Micro Circular
Product Type	Male Inline Underwater Connector
Nombre de contacts	21
Contact Gender	Male
Contact Finish	Gold-Plated
Standard Body Material	Neoprene Rubber
Rated Current	5 A per Contact
Voltage Rating	Up to 550 V AC/DC, Depending on Configuration
Maximum Series Pressure Rating	60 MPa
Approximate Depth Rating	6,000 m Seawater
Standard Cable Length	1 Meter
Compatible Female Bulkhead Connector	MCBH21F
Compatible Female Inline Connector	MCIL21F
Protective Dummy Connector	MCDC21F
Connector Technology	Wet-Mateable Micro Circular
Brand Compatibility	Corresponding SubConn and SEACON Interfaces
Custom Cable Assemblies	Available
Warranty	12 Months

Technical Note: Electrical performance, pressure capability, cable specifications, and mating compatibility depend on the complete connector configuration. The applicable current rating should be verified against the conductor size and expected operating conditions.

High-Density 21-Pin Electrical Connectivity

Modern underwater equipment often requires multiple electrical circuits for sensors, control systems, monitoring devices, and auxiliary equipment.A typical underwater research system may include several instruments that need electrical power, measurement signals, control commands, and diagnostic connections.Using separate connectors for every circuit can increase the number of connection points, complicate cable management, and require additional installation space.The MCIL21M 21-contact underwater electrical connector helps address these challenges by combining 21 electrical contacts within one compact Micro Circular connector interface.This arrangement provides engineers with flexibility when designing complex subsea wiring systems.Possible applications include:

• Underwater sensor signal transmission
• ROV equipment control circuits
• AUV instrumentation connections
• Low-power auxiliary equipment
• Multi-channel monitoring systems
• Oceanographic data acquisition
• Underwater actuator feedback signals
• Marine electronic instrumentation
• Subsea diagnostic connections

The exact function assigned to each contact depends on the customer’s electrical design.For projects combining power and signal circuits, engineers should evaluate current loading, conductor size, voltage drop, shielding, electromagnetic interference, and cable construction.A 21-pin configuration provides multiple electrical connections but does not automatically guarantee compatibility with a particular high-speed communication protocol.Applications involving Ethernet or other high-frequency signals should be evaluated using the complete cable assembly.

Wet-Mateable Connector Design

The MCIL21M belongs to the HYSF SUBSEA Micro Circular wet-mateable connector family.Wet-mateable underwater connectors are designed to support connection and disconnection in submerged environments when compatible mating components are used.This capability is particularly valuable for equipment requiring periodic maintenance or replacement.Typical examples include:

• ROV payload changes
• Underwater instrument servicing
• AUV module replacement
• Subsea cable maintenance
• Marine research equipment installation
• Underwater sensor replacement

The MCIL21M features a male mating interface designed to engage with a corresponding female connector.During mating, the connector should be correctly aligned and its mating surfaces should be inspected for contamination or damage.The connector should not be forced into an incompatible interface.Unless the complete electrical system has been specifically approved for energized mating, power should be switched off before connecting or disconnecting underwater connectors.

Durable Neoprene Rubber Construction

The MCIL21M features a molded neoprene rubber body intended for demanding marine environments.Neoprene is commonly used in underwater electrical connectors because it provides flexibility and resistance to moisture.The molded construction helps protect the internal electrical contacts and cable termination against environmental exposure.Subsea connectors may experience:

• Continuous contact with seawater
• High hydrostatic pressure
• Equipment vibration
• Mechanical handling
• Repeated deployment and recovery
• Offshore weather conditions
• Extended underwater operation

The MCIL21M is designed with these operating challenges in mind.Its gold-plated male contacts provide a stable electrical mating surface.Gold plating is commonly used in high-reliability electrical connectors to reduce contact corrosion and support consistent electrical performance.For reliable long-term operation, proper inspection, cleaning, and connector handling remain important.

Deep-Sea Pressure Capability up to 6,000 Meters

The HYSF SUBSEA Micro Circular connector series is designed for underwater pressure conditions reaching approximately 60 MPa.This corresponds to an approximate seawater depth of 6,000 meters.The MCIL21M is therefore suitable for consideration in demanding deep-sea applications, including oceanographic instruments, underwater robotic platforms, and subsea monitoring equipment.However, connector depth capability must be evaluated in the context of the complete installed assembly.Important factors include:

1. Correct male-to-female connector mating
2. Compatible sealing surfaces
3. Appropriate cable construction
4. Reliable cable termination
5. Proper locking and mechanical retention
6. Environmental operating conditions
7. Verification of the complete assembly

For critical underwater systems, qualification testing should reflect the intended operating pressure and installation conditions.

Standard 1-Meter Cable and Custom Cable Lengths

The standard MCIL21M configuration is supplied with approximately 1 meter of cable.This length is suitable for many equipment integration and testing applications.However, cable length requirements can vary significantly depending on the system.For example, a compact underwater sensor may require a short connection to a nearby pressure housing, while a larger ROV or oceanographic platform may require a longer cable assembly.HYSF SUBSEA supports customized cable configurations for OEM projects.Available customization options may include:

• Customized cable lengths
• Alternative cable specifications
• Project-specific conductor arrangements
• Customized wire identification
• Customer-defined pin assignments
• Male-to-female cable assemblies
• Open-ended underwater cable assemblies
• Specialized subsea equipment connections

For example, an MCIL21M to MCIL21F underwater cable assembly can be configured with a project-specific cable length.The required wiring arrangement should be defined before production and confirmed in the approved technical documentation.

Compatible Mating Connectors

The MCIL21M is a male inline connector with 21 male electrical contacts.It is designed to mate with corresponding female Micro Circular connectors.

MCBH21F – 21-Pin Female Bulkhead Connector

Les MCBH21F is a panel-mounted female underwater connector designed for installation on subsea equipment housings.When paired with the MCIL21M, it provides a detachable connection between an external underwater cable and the internal electronics of a pressure-resistant enclosure.A typical configuration is:MCIL21M Male Inline Cable → MCBH21F Female Bulkhead Connector → Internal Equipment WiringThis arrangement is suitable for underwater electronic housings, ROV control modules, oceanographic instruments, and subsea monitoring equipment.The corresponding MCBH21F bulkhead family uses a 5/8-18 UNF-2A mounting thread. Final mounting dimensions should be confirmed from its approved technical drawing.

MCIL21F – 21-Pin Female Inline Connector

Les MCIL21F is the corresponding female inline underwater connector.It can be paired with the MCIL21M to form a detachable cable-to-cable connection.A typical arrangement is:MCIL21M Male Inline Connector → MCIL21F Female Inline ConnectorThis configuration is useful for underwater cable extensions and modular electrical systems.

Protective Dummy Connector: MCDC21F

When the MCIL21M is disconnected from its mating female connector, its exposed male electrical contacts should be protected.The corresponding protective accessory is the MCDC21F 21-pin female dummy connector.The MCDC21F is designed to cover and protect compatible male connector interfaces during storage, transportation, maintenance, and periods when the working electrical connection is not required.A suitable protective dummy connector helps reduce the risk of contamination and mechanical damage.The MCDC21F is a protective accessory rather than a functional electrical connector.

SubConn and SEACON Compatible Design

HYSF SUBSEA manufactures Micro Circular underwater connectors designed for compatibility with corresponding SubConn and SEACON connector interfaces.The MCIL21M provides an alternative for customers seeking a SubConn-compatible 21-pin male inline underwater connector.This is particularly relevant for subsea equipment manufacturers and maintenance teams working with existing Micro Circular connector systems.However, engineers should verify the exact mating configuration before using connectors from different manufacturers.Important considerations include:

• Contact count and arrangement
• Male or female interface
• Connector dimensions
• Mechanical keying
• Locking mechanism
• Electrical ratings
• Cable wiring configuration

The MCIL21M should not be confused with Standard Circular connectors or dedicated Ethernet-series connectors.

Typical Applications of the MCIL21M

1. Remotely Operated Vehicles (ROVs)

ROVs commonly require electrical connections for cameras, sensors, control equipment, and auxiliary systems.The MCIL21M provides a compact interface for integrating multiple circuits into a single subsea cable connection.

2. Autonomous Underwater Vehicles (AUVs)

AUVs often contain numerous electronic instruments within limited installation space.The high-density 21-pin design is suitable for modular electrical connections between external equipment and underwater control systems.

3. Oceanographic Research Equipment

Marine research platforms may require multiple electrical channels for measurement instruments and monitoring equipment.The MCIL21M can be used in suitable underwater cable assemblies connecting these devices.

4. Subsea Sensor Networks

Underwater monitoring platforms frequently integrate several sensors and control circuits.A 21-pin connector provides flexibility for multi-channel electrical interfaces.

5. Sonar and Hydrophone Systems

Underwater acoustic equipment may use multiple signal channels and auxiliary power connections.The MCIL21M can be considered for these applications when the proposed cable design meets the required electrical and signal-integrity specifications.

6. Offshore Inspection Equipment

Marine inspection systems require reliable electrical connections in harsh operating environments.The MCIL21M offers a compact solution for appropriately rated subsea instrumentation and control applications.

Standard 21-Pin Wire Color Identification

For reference, the HYSF SUBSEA Micro Circular 21-pin series uses the following standard cable color identification sequence:

Pin Number	Wire Color
1	Red
2	Red/White
3	Black
4	Black/White
5	Yellow
6	Yellow/White
7	Blue
8	Blue/White
9	Orange
10	Orange/White
11	Brown
12	Brown/White
13	Purple
14	Purple/White
15	Green
16	Green/White
17	Pink
18	Pink/White
19	Light Blue
20	Light Blue/White
21	Grey

Note: This sequence is the standard series reference. Custom cable assemblies may use different conductor colors or wiring arrangements. Always follow the approved wiring diagram for the specific product configuration.

Quality Control and Testing

Electrical connector reliability is especially important for subsea equipment.HYSF SUBSEA applies quality-control processes designed to support reliable underwater connector performance.Depending on the product configuration, testing may include:

• Hydrostatic pressure testing
• Electrical continuity testing
• Insulation resistance testing
• Dielectric withstand testing
• Contact inspection
• Connector mating verification
• Cable assembly inspection
• Visual inspection of molded components
• Mechanical and environmental testing

Additional testing requirements can be considered for projects with specific operating conditions.

Frequently Asked Questions

What is the MCIL21M?

The MCIL21M is a 21-pin male Micro Circular underwater inline connector manufactured by HYSF SUBSEA. It is designed for multi-circuit electrical connections in subsea environments.

Is MCIL21M a male or female connector?

The MCIL21M is a male connector featuring 21 male electrical contacts.

Which connector mates with MCIL21M?

The recommended mating connectors are the MCBH21F female bulkhead connector and MCIL21F female inline connector.

What is the standard cable length?

The standard MCIL21M cable length is 1 meter. Customized cable lengths are available for OEM applications.

What is the maximum operating depth?

The standard Micro Circular connector series is designed for pressures up to 60 MPa, approximately equivalent to 6,000 meters of seawater, subject to complete assembly qualification.

Is MCIL21M compatible with SubConn connectors?

The MCIL21M is designed for corresponding SubConn-style Micro Circular interfaces. Exact mechanical and electrical compatibility should be confirmed before cross-brand mating.

What is the rated current of MCIL21M?

The standard series is rated at 5 A per contact. Actual allowable loading depends on conductor size, simultaneous circuit use, and operating conditions.

Can MCIL21M be used for both power and signals?

Yes. Different contacts can be assigned to appropriate power and signal circuits, provided the complete electrical design satisfies the applicable requirements.

Which dummy connector protects MCIL21M?

The corresponding protective accessory is the MCDC21F 21-pin female dummy connector.

Can the cable length be customized?

Yes. HYSF SUBSEA supports custom cable lengths, wiring arrangements, and complete underwater cable assemblies for OEM projects.

High-Density 21-Pin Underwater Connectivity

Les HYSF SUBSEA MCIL21M 21-pin male inline underwater connector provides a compact, configurable electrical interface for demanding marine equipment.With its 21-contact arrangement, durable neoprene rubber body, gold-plated contacts, and deep-sea pressure capability, the MCIL21M is suitable for underwater robotics, oceanographic research, marine monitoring, and subsea instrumentation.For engineers searching for a 21-pin male underwater cable connector, a SubConn-compatible Micro Circular inline connector, or a deep-sea waterproof connector for ROV and AUV applications, the MCIL21M offers a practical solution within the HYSF SUBSEA Micro Circular connector range.