Appliances And HVAC
Compact power and signal harnesses for controls, fans, sensors, and serviceable internal modules.
Molex 3.0mm Fit power and signal connectors
Molex Micro-Fit 3.0 connectors for mid-density power and signal
Select Micro-Fit 3.0 single-row or dual-row housings, 43030 and 43031 terminals, TPA retainers, wire range, and circuit count for compact power and signal harnesses.
3.00mm Pitch2-24 Circuits18-30 AWG600V
Why Molex Micro-Fit 3.0 connectors exist
Molex Micro-Fit 3.0 is the 3.0mm Fit workhorse for compact power and signal circuits. It sits between Nano-Fit and Mini-Fit Jr. when the design needs more density than 4.2mm pitch but more availability and current headroom than very small connectors.
Dual-row Micro-Fit 3.0 uses 43025 receptacle housings and 43020 plug housings across 2-24 circuits. Single-row Micro-Fit 3.0 uses 43645 receptacles and 43640 plugs across 2-12 circuits.
The common terminal stack is 43030 female terminals into receptacles and 43031 male terminals into plugs. TPA families add secondary retention options for both dual-row and selected single-row layouts.
MiniProto stocks Micro-Fit 3.0 housings, terminal families, and TPA options across 143 connector entries in the live configurator catalog.
Why teams choose Molex Micro-Fit 3.0
Micro-Fit 3.0 is useful when the connector needs to carry modest power, fit dense packaging, and stay serviceable across appliance, server, medical, solar, HVAC, and robotics harnesses.
Mid-Density
3.0mm pitch saves package space while keeping a familiar crimped power and signal connector workflow.
Single Or Dual Row
Choose single-row 2-12 circuits for flatter routing or dual-row 2-24 circuits for density.
TPA Options
Multiple TPA families support secondary retention when the application needs more terminal assurance.
Where Molex Micro-Fit 3.0 earns its place
Servers And Networking
Router, storage, data-center, and AI server power layouts where dense connector packaging matters.
Medical And Robotics
Diagnostics, patient monitors, robotic modules, and machine wiring that need compact keyed interconnects.
Fit family comparison
Pick the Fit family by pitch, wire range, circuit count, and the exact terminal and wire condition behind the current rating.
Nano-Fit
Compact signal and power, tight packaging
2.5mm
20-26 AWG
- Max Current*
- 8.0A with 105300 terminals and 20 AWG in a 2-circuit wire-to-board set
- Circuits
- 2-8 single / 4-16 dual
Micro-Fit 3.0
Mid-density power and signal workhorse
3.0mm
18-30 AWG
- Max Current*
- 8.5A with 43030 terminal and 18 AWG
- Circuits
- 2-12 single / 2-24 dual
Ultra-Fit
Compact 600V power with glow-wire options
3.5mm
16-22 AWG
- Max Current*
- 14A with 172253 tin terminals and 16 AWG in a 2-circuit single-row wire-to-board set
- Circuits
- 2-8 single / 4-16 dual
Mini-Fit Jr.
Classic power interconnect
4.2mm
16-28 AWG
- Max Current*
- 9A with 5556 terminal and 24-18 AWG variant; 13A with 45750 HCS terminal and 16 AWG
- Circuits
- 2-24 dual
Mega-Fit
High-current power runs
5.7mm
10-16 AWG
- Max Current*
- 23A at 600V with Mega-Fit terminals and 12 AWG; 30A peak with Mega-Fit terminals and 10 AWG in a 2-circuit wire-to-wire set
- Circuits
- 2-8 single / 2-12 dual
| Family | Pitch | Max Current* | Wire | Circuits | Use |
|---|---|---|---|---|---|
| Nano-Fit | 2.5mm | 8.0A with 105300 terminals and 20 AWG in a 2-circuit wire-to-board set | 20-26 AWG | 2-8 single / 4-16 dual | Compact signal and power, tight packaging |
| Micro-Fit 3.0 | 3.0mm | 8.5A with 43030 terminal and 18 AWG | 18-30 AWG | 2-12 single / 2-24 dual | Mid-density power and signal workhorse |
| Ultra-Fit | 3.5mm | 14A with 172253 tin terminals and 16 AWG in a 2-circuit single-row wire-to-board set | 16-22 AWG | 2-8 single / 4-16 dual | Compact 600V power with glow-wire options |
| Mini-Fit Jr. | 4.2mm | 9A with 5556 terminal and 24-18 AWG variant; 13A with 45750 HCS terminal and 16 AWG | 16-28 AWG | 2-24 dual | Classic power interconnect |
| Mega-Fit | 5.7mm | 23A at 600V with Mega-Fit terminals and 12 AWG; 30A peak with Mega-Fit terminals and 10 AWG in a 2-circuit wire-to-wire set | 10-16 AWG | 2-8 single / 2-12 dual | High-current power runs |
*Max current is the best case from Molex family data. Real limits come from the exact terminal, wire, circuit count, ambient temperature, and housing selected.
Choose Micro-Fit 3.0 when 3.0mm pitch and 18-30 AWG wire coverage fit the job. Step down to Nano-Fit for tighter packaging, up to Mini-Fit Jr. for classic 4.2mm power interconnects, or up to Mega-Fit for heavier wire and higher-current power runs.
The Micro-Fit 3.0 limits that matter
Use Micro-Fit 3.0 for 3.0mm pitch power and signal circuits. The 8.5A condition requires a 43030 terminal with 18 AWG wire, while smaller wire is derated by the selected terminal and housing.
Electrical
- Pitch
- 3.00mm
- Top Current
- 8.5A with 43030 terminal and 18 AWG
- Derated Examples
- 5A with selected terminal and 20 AWG to 1A with selected terminal and 30 AWG
- Voltage
- 600V
Mechanical
- Dual Row
- 2-24 circuits, 43025 receptacle, 43020 plug
- Single Row
- 2-12 circuits, 43645 receptacle, 43640 plug
- Mating Cycles
- About 30
- Terminals
- 43030 female, 43031 male
Environmental
- Temperature
- -40 to 105 C
- Sealing
- Non-sealed family
- Use
- Appliance, telecom, medical, solar, automotive interior, server, HVAC, robotics
Materials
- Dual TPA Receptacle
- 172952 with 172953 retainers
- Dual TPA Plug
- 203632
- Single TPA Receptacle
- 171850 for 2-7 circuits
- Single TPA Plug
- 200875 for 2-7 circuits
Reference data comes from manufacturer CAD models and Molex family catalog data; verify final ratings against the exact selected contact and housing.
Positions, rows, and keying
Micro-Fit 3.0 circuit counts
Common dual-row 43025 receptacle housing sizes. Single-row Micro-Fit 3.0 covers 2-12 circuits, while dual-row covers 2-24 circuits.
2-Circuit
43025
4-Circuit
43025
6-Circuit
430258-Circuit
43025
12-Circuit
43025
24-Circuit
43025
Use the selected housing drawing and connector-side view before assigning cavities. Single-row and dual-row Micro-Fit 3.0 layouts are not interchangeable.
Single-row, dual-row, and TPA choices
Start with row format: single-row for flatter packaging or dual-row for density. Then select the matching receptacle, plug, terminal, and TPA family.
Micro-Fit 3.0 does not mate with Mini-Fit Jr., Nano-Fit, Mega-Fit, or other pitches. Similar family names do not imply physical compatibility.
Micro-Fit 3.0 connector stack
What completes a Micro-Fit 3.0 connection
A Micro-Fit 3.0 connection combines a matching receptacle and plug housing, 43030 female terminals, 43031 male terminals, and optional TPA retainers selected for the row format.
For board transitions or dense equipment modules, confirm row count and cable exit direction before assigning pinout and wire gauge.
- Dual-Row Housings
- 43025 receptacle, 43020 plugCovers 2-24 circuits.
- Single-Row Housings
- 43645 receptacle, 43640 plugCovers 2-12 circuits.
- Terminals
- 43030 female, 43031 maleMatch terminal to conductor gauge and current condition.
- TPA Options
- 172952, 172953, 203632, 171850, 200875Select TPA by row format, circuit count, and housing side.
Contact and accessory choices
Micro-Fit 3.0 uses 43030 female terminals in receptacles and 43031 male terminals in plugs. Terminal and wire choice set current and derating.
Female Terminal Side
- Terminal
- 43030 female
- Housing
- 43025 or 43645 receptacle
- Wire
- 18-30 AWG by selected terminal
- Current
- 8.5A with 43030 terminal and 18 AWG
Male Terminal Side
- Terminal
- 43031 male
- Housing
- 43020 or 43640 plug
- Wire
- 18-30 AWG by selected terminal
- Use
- Pairs with matching receptacle side
For quoting, keep receptacle, plug, terminal, and TPA rows together. A Micro-Fit 3.0 housing alone does not define current without the selected terminal and wire.
Wire range and derating
Micro-Fit 3.0 spans 18-30 AWG, but the top current condition is tied to 43030 female terminals with 18 AWG wire.
Smaller wire changes the current plan. Preserve the terminal and gauge in the BOM when moving from prototype to production.
Wire and fit checks
- Wire Range
- 18-30 AWG
- Top Current
- 8.5A with 43030 terminal and 18 AWG
- Derating
- 5A with selected terminal and 20 AWG to 1A with selected terminal and 30 AWG
- Rows
- Single-row or dual-row
Final wire choice comes from the exact housing, terminal, insulation OD, bend radius, and bundle temperature. Gauge alone is not enough.
What drives cost
Micro-Fit 3.0 cost moves with row format, circuit count, TPA retainers, and whether the build needs broad 18-30 AWG terminal coverage.
- Row Format
- Single-row lower density, dual-row higher densityDual-row usually buys packaging density at the cost of more complex routing and inspection.
- TPA Hardware
- No TPA lower, TPA stack higherUse TPA when terminal assurance matters enough to justify the added parts.
- Circuit Count
- 2 circuits lower, 24 circuits higherMore circuits add terminals, wire prep, crimp inspection, and continuity test time.
Stock and sourcing
MiniProto stocks Micro-Fit 3.0 housings and TPA families across 143 connector entries from 2-24 pins in the live configurator catalog. We quote the row format, terminal, TPA, and wire condition as a matched stack.
Assembly, and the mistakes to avoid
- !Do not use the 8.5A condition unless the build uses a 43030 terminal with 18 AWG wire.
- !Do not mix single-row and dual-row housing assumptions. Receptacle, plug, and TPA families change with row format.
- !Do not assume Micro-Fit 3.0 mates with Mini-Fit Jr. The pitches are different.
- !Do not omit the TPA line item when the customer drawing calls for secondary retention.
Common questions
What is Molex Micro-Fit 3.0 used for?+
Molex Micro-Fit 3.0 is a 3.0mm pitch power and signal connector family for appliances, telecom and networking hardware, medical diagnostics, patient monitors, solar equipment, non-sealed automotive electronics, data-center server power, HVAC, and robotics.
How much current can Micro-Fit 3.0 carry?+
The top Micro-Fit 3.0 condition is 8.5A with a 43030 female terminal and 18 AWG wire. Molex data also lists lower derated values across smaller wire, including 5A with 20 AWG and 1A with 30 AWG for the selected terminal and housing.
What do receptacle and plug part numbers mean?+
For Micro-Fit 3.0, 43025 is a dual-row receptacle housing and 43020 is a dual-row plug housing. Single-row families include 43645 receptacles and 43640 plugs.
Should I choose single-row or dual-row Micro-Fit 3.0?+
Use single-row Micro-Fit 3.0 for 2-12 circuits when the harness needs a flatter profile. Use dual-row Micro-Fit 3.0 for 2-24 circuits when density matters more.
Which TPA options exist?+
TPA options include 172952 dual-row receptacle retainers with 172953 retainers, 203632 dual-row plug TPA, 171850 single-row receptacle TPA for 2-7 circuits, and 200875 single-row plug TPA for 2-7 circuits.
Does Micro-Fit 3.0 mate with Mini-Fit Jr.?+
No. Micro-Fit 3.0 uses 3.0mm pitch. Mini-Fit Jr. uses 4.2mm pitch, so the housings do not intermate.
Build your Molex Micro-Fit 3.0 harness
Pick positions, contacts, and wire. See the price as you go, then send it to our floor.