Anderson SB Series Connector & Contact Sizer
Select multipole SB50, SB120, SB175, and SB350 housings, voltage color keys, contact barrel IDs, reducing bushings, and UL 1977 hot-plug disconnect ratings.
Quick Engineering Answer: How Do You Size Anderson SB Connectors?
UL 1977 • EN 1175-1 • CSA C22.2Anderson SB (Storage Battery) connectors are sized by two independent constraints: continuous electrical load (amperes) and conductor barrel geometry (AWG/mm²). Housing series determine maximum continuous current: SB50 (up to 50A / 6 AWG), SB120 (up to 120A / 2 AWG), SB175 (up to 175A / 1/0 AWG), and SB350 (up to 350A / 4/0 AWG). Housing colors are mechanically keyed to nominal DC voltages (Yellow = 12V, Red = 24V, Grey = 36V, Blue = 48V) and cannot physically intermate. When terminating undersized conductors into larger housings, precision copper reducing bushings must be inserted to prevent barrel voids and maintain low contact resistance.
Connector & Circuit Parameters
Engineering Specifications & Mating Logic
Select your housing series, system voltage, and conductor gauge, then click Size SB Connector & Contacts.
Engineering Methodology for Anderson SB Multipole Terminations
Governing Physics & Design Criteria
Anderson Power Products SB connectors use a genderless hermaphroditic design: identical housings mate together upside down. Contact retention relies on internal stainless steel leaf springs that exert constant mechanical pressure against silver-plated copper wiping contacts.
- Self-Cleaning Wiping Action: Every mating cycle wipes oxide accumulation off the contact tips, maintaining low interfacial resistance (≤ 100 μΩ).
- Mechanical Voltage Keying: Color options are not cosmetic; each color features proprietary physical indexing ribs that prevent incorrect voltage cross-connections.
- Reducing Bushings: When smaller cables are terminated into oversized contacts (such as 4 AWG wire into an SB175 barrel rated for 1/0 AWG), heavy-wall electrolytic copper reducing bushings (#5687, #5919, #5918) must be used to eliminate voids that cause high-resistance hotspots.
ΔT = I2 × Rcontact × θthermal ≤ 30°CRcontact,effective = Rbarrel + Rbushing + Rinterface (≤ 100 μΩ)
Circuit Condition: A 24V marine lithium battery bank feeds a 95A continuous auxiliary distribution panel using 4 AWG flexible marine cable. Sizing the quick-disconnect system:
1. Housing Selection: Continuous load is 95A. While SB50 is limited to 50A, SB120 and SB175 both handle 95A. Selecting SB175 provides generous thermal headroom and accepts future expansion.
2. Voltage Key Matching: For 24V DC, the standardized keying color is Red (Anderson part #6331G1). It mechanically prevents mating with 12V Yellow or 48V Blue shore connectors.
3. Contact Sizing & Bushing: Standard SB175 contacts (part #1383) have an inside barrel diameter of 11.1 mm (designed for 1/0 AWG). Inserting a 4 AWG conductor requires reducing bushing #5919 (barrel reduced to 6.9 mm ID).
4. Strip Length & Crimp: Conductor must be stripped to 28.6 mm (1.13 inches). The assembly is crimped using a 25 mm² hexagonal hydraulic die or dual-indent tool.
Anderson SB Series Empirical Specifications Matrix
Dimensions, ratings, and reducing bushing options compiled from published manufacturer specifications:
| Housing Series | UL Continuous Amps | Standard Wire Range | Contact Barrel ID (mm / in) | Standard Voltage Key Colors | Reducing Bushing Part Numbers | Strip Length |
|---|---|---|---|---|---|---|
| SB50 | 50A | 12 AWG – 6 AWG | 5.1 mm (0.200 in) | Yellow (12V), Red (24V), Grey (36V), Blue (48V), Black (80V) | #5910 (10-12 AWG), #5912 (8 AWG) | 14.3 mm (0.56 in) |
| SB120 | 120A | 6 AWG – 2 AWG | 7.5 mm (0.297 in) | Red (24V), Grey (36V), Blue (48V) | #5687 (6 AWG), #5919 (4 AWG) | 19.0 mm (0.75 in) |
| SB175 | 175A | 4 AWG – 1/0 AWG | 11.1 mm (0.437 in) | Yellow (12V), Orange (18V), Red (24V), Grey (36V), Blue (48V) | #5687 (6 AWG), #5919 (4 AWG), #5918 (2 AWG) | 28.6 mm (1.13 in) |
| SB350 | 350A | 2/0 AWG – 4/0 AWG | 14.3 mm (0.563 in) | Yellow (12V), Red (24V), Grey (36V), Blue (48V), Green (72V) | #5917 (1/0 AWG), #5915 (2/0 AWG) | 34.9 mm (1.38 in) |
Frequently Asked Questions
Can you mechanically mate Anderson SB housings of different colors?
No. Anderson SB series multipole housings (SB50, SB120, SB175, SB350) feature unique internal mechanical alignment keys molded into each color. A 24V Red housing cannot physically mate into a 12V Yellow, 36V Grey, or 48V Blue housing, preventing accidental cross-connection between different system voltages.
When should reducing bushings be used with Anderson SB contacts?
Reducing bushings must be used whenever you terminate a wire gauge smaller than the contact barrel's rated minimum. For example, terminating a 4 AWG wire into an SB175 contact barrel (designed for 1/0 AWG) requires Anderson reducing bushing #5919 to eliminate air voids and ensure a gas-tight mechanical crimp.
What is the UL 1977 hot-plug disconnect rating for Anderson SB connectors?
Under UL 1977 testing, Anderson SB contacts are rated for 250 disconnect cycles under full electrical load at 120V to 600V DC. In non-load cold disconnect conditions, the silver-plated copper wiping contacts achieve up to 10,000 mechanical mating cycles.
Should fine-strand battery cables be crimped or soldered into Anderson SB contacts?
Precision hex or dual-indent crimping using calibrated tooling is recommended. Soldering can wick molten alloy into the flexible stranded conductor, hardening the wire at the barrel junction and creating a severe stress-concentration point susceptible to vibration fatigue.