RH7101B-2.8-21/929504-4 12 V / 24 V / 48 V, 10 Position, Automotive Housing for Female Terminals

1. Overview and Primary Application

The RH7101B-2.8-21/929504-4 is a 10-position, 2-row automotive-grade connector housing designed for female terminals. Unlike lower-voltage housings limited to 12V systems, this housing is rated for three nominal voltage architectures: 12 V, 24 V, and 48 V. This multi-voltage capability makes it suitable for a wide range of applications, from standard 12V passenger cars and 24V commercial trucks to emerging 48V mild hybrid systems and light electric vehicles. The housing is non-sealable (Sealable: No), so it is intended for dry or protected environments where direct water spray or immersion is not expected. Each contact supports a maximum current rating of 30 A, making this connector suitable for power distribution circuits in addition to signal applications.

2. Mechanical and Housing Construction

The housing has a rectangular shape and is molded in black primary product color from Polybutylene Terephthalate (PBT). PBT is a thermoplastic polyester known for high mechanical strength, dimensional stability, and resistance to heat and automotive fluids. The black color is typical for underhood or power applications where UV exposure is minimal or not a concern.

Key mechanical attributes include:

Primary locking feature: Integrated in Housing – Locking Lance. This means the terminal retention feature is molded directly into the housing cavity. The locking lance deflects during terminal insertion and snaps behind the terminal's shoulder to provide secure retention.

Mixed & Hybrid Connector: No – all 10 positions accept the same contact size (2.8mm receptacle).

Mating alignment: With – polarization features are included to ensure correct orientation with the mating header or male housing.

Mating alignment type: Polarization – keyways, ribs, or asymmetrical side walls guide the mating connector into the correct position, preventing misinsertion.

Strain relief: Without – no integrated strain relief; external cable management may be required in high-vibration applications.

Terminal Position Assurance (TPA): No – the locking lance is the sole means of terminal retention.

Connector mounting type: Cable Mount (Free-Hanging) – designed for attachment to wires and cables, not for panel or PCB mounting.

Cable exit angle: 180° – straight or inline cable exit.

3. Contact and Electrical Specifications

The housing accommodates receptacle-type contacts with a contact size of 2.8 mm and a mating tab width of 2.8 mm (0.11 in). The 2.8mm terminal system is a widely used industry standard for medium to high-current automotive power and ground circuits. Each contact has a maximum current rating of 30 A.

Key electrical parameters:

Nominal Voltage Architecture: 12 V, 24 V, or 48 V (multi-voltage compatible)

Contact current rating (max): 30 A per contact

This combination of 30A current capacity and multi-voltage support (12/24/48V DC) makes the housing suitable for:

12V systems: Standard passenger car power distribution, lighting, motor circuits

24V systems: Trucks, buses, commercial vehicles, construction equipment

48V systems: Mild hybrid electric vehicles (MHEV), golf carts, low-speed electric vehicles, power distribution units

The contact type is Receptacle (female terminal), which receives the mating tab from the corresponding male header or connector.

4. Configuration and Dimensional Data

The housing provides 10 positions arranged in 2 rows. Key dimensional specifications are:

Centerline (pitch): 5 mm (0.197 in). This larger pitch compared to 2.2mm or 2.5mm signal connectors provides increased creepage and clearance distances, which is essential for higher voltage (48V) and higher current (30A) applications.

Row-to-row spacing: 5.6 mm (0.22 in)

Product length: 33.5 mm (1.31 in)

Product width: 29.5 mm (1.16 in) – note that width and height are equal (both 29.5 mm).

Connector height: 29.5 mm (1.16 in)

The 2-row configuration with 5 mm pitch and 5.6 mm row spacing results in a robust, moderately sized rectangular housing. The equal width and height dimensions (29.5 mm × 29.5 mm) suggest a near-square footprint, which can be advantageous for harness routing in confined spaces.

5. Environmental and Thermal Performance

The operating temperature range is -40 to 130 °C (-40 to 266 °F), with a maximum rated temperature of 130 °C. This expanded temperature range is significantly wider than standard automotive connector ranges that typically stop at 105 °C. Key distinctions:

Lower limit: -40 °C – suitable for cold climates and harsh winter conditions.

Upper limit: 130 °C – capable of withstanding higher underhood temperatures, near engine surfaces, or in applications with high ambient heat (e.g., near exhaust systems, turbochargers, or in engine compartments of heavy-duty vehicles).

The housing is explicitly non-sealable (Sealable: No). It does not include provisions for silicone seals, gaskets, or mat seals. Therefore, it must not be used in locations exposed to direct water spray, high-pressure washing, condensation pools, or submersion. The PBT material provides good resistance to common automotive fluids (oil, fuel, coolant, salt spray) at moderate exposure levels, but the lack of sealing means fluid ingress into contact cavities is possible if the connector is directly wetted. For dry, hot, or dust-only environments, this housing delivers excellent performance.

6. Connector System and Locking Features

The connector system supports two mating configurations:

Wire-to-Board (with a compatible PCB-mounted header that has 2.8mm tabs)

Wire-to-Wire (with a matching male plug housing)

The primary locking feature is the Locking Lance, integrated directly into the housing. When a female terminal is fully inserted, the lance snaps into the terminal's primary locking window or behind a shoulder, providing audible and tactile feedback. There is no Terminal Position Assurance (TPA) device. The locking lance is the sole means of terminal retention. This simplifies assembly and reduces component cost but requires careful insertion to ensure the lance is fully engaged. Given the 30A current rating, proper terminal crimping and full seating are critical to avoid heat generation or intermittent connections.

No strain relief is provided. In high-vibration environments (e.g., engine-adjacent or drivetrain applications), external strain relief such as cable ties, conduit, or adhesive-lined heat shrink tubing is strongly recommended to prevent forces from transmitting to the terminal crimp and locking lance.