Type 1 Connector (SAE J1772) - Pinout, Wiring & Complete Specs
Everything about the Type 1 / SAE J1772 EV connector: 5-pin layout, Control Pilot signaling, wire gauges, power levels, and installation details.
Type 1 Connector (SAE J1772). Pinout, Wiring & Complete Specs
The Type 1 connector. officially SAE J1772. is the standard AC charging plug in North America, Japan, and a handful of other markets. It handles Level 1 (household outlet) and Level 2 (dedicated EVSE) charging. If you've plugged in a Nissan Leaf, a Chevy Bolt, or any non-Tesla EV in the US, you've used this connector.
It's a 5-pin, single-phase AC plug. No DC capability. No three-phase. Just straightforward single-phase AC, up to 19.2 kW.
Physical layout
The Type 1 plug has a round body with a flat top, roughly 43 mm in diameter. Five pins arranged in a specific pattern with a mechanical latch on top that clicks into the vehicle inlet. The latch is spring-loaded. pull the trigger to release.
Rendering diagram...
The two small pins at the top are the signaling pins (CP and PP). The three large pins below carry power. Earth/ground is the largest, centered at the bottom.
Pin assignments
| Pin | Name | Function | Diameter |
|---|---|---|---|
| L1 | AC Line | Single-phase AC hot conductor | 6.35 mm |
| N | Neutral | AC return path | 6.35 mm |
| PE | Protective Earth | Ground / chassis bond | 7.62 mm (larger) |
| CP | Control Pilot | Signaling between EVSE and vehicle | 3.17 mm |
| PP | Proximity Pilot | Plug insertion detection / current limit | 3.17 mm |
The PE pin is deliberately larger and longer than L1 and N. It makes contact first when inserting and breaks contact last when removing. This ensures the ground path is always established before live conductors connect. a basic safety requirement.
Control Pilot (CP). the brain of the connection
The CP pin is where the real intelligence lives. It's a 1 kHz PWM (Pulse Width Modulation) signal generated by the EVSE, running at +/- 12V.
Rendering diagram...
CP state machine
| State | CP Voltage | Meaning | EVSE Action |
|---|---|---|---|
| A | +12V DC | No vehicle connected | Standby, no power |
| B | +9V (PWM) | Vehicle connected, not ready | PWM running, no power |
| C | +6V (PWM) | Vehicle ready, charging requested | Energize AC, allow current |
| D | +3V (PWM) | Vehicle needs ventilation | Energize if ventilation OK |
| E | 0V | EVSE fault | Shut down |
| F | -12V | EVSE not available | No service |
PWM duty cycle = current limit
The duty cycle of the 1 kHz signal tells the vehicle how much current it's allowed to draw:
| Duty Cycle | Max Current |
|---|---|
| 10% | 6 A |
| 16% | 10 A |
| 25% | 16 A |
| 30% | 18 A |
| 40% | 24 A |
| 50% | 30 A |
| 60% | 36 A |
| 80% | 48 A |
| 96% | 80 A |
Formula: Current (A) = Duty Cycle (%) x 0.6 for duty cycles between 10% and 85%.
Above 85%: Current (A) = (Duty Cycle (%) - 64) x 2.5
A 100% duty means "no PWM communication". the EVSE is a basic outlet with no signaling (Level 1 dumb charging).
Proximity Pilot (PP). plug detection and current limit
The PP pin serves two purposes:
- Plug detection: the vehicle knows a plug is inserted by sensing the PP resistance to ground
- Cable current rating: the resistance value encodes the cable's maximum current capacity
| PP Resistance | Cable Rating |
|---|---|
| 100 ohm | 63 A (not used in Type 1, but defined) |
| 220 ohm | 32 A |
| 680 ohm | 20 A |
| 1.5 kohm | 13 A |
| No connection | No cable inserted |
In practice, for Type 1 with attached cables on the EVSE (the common US setup), the PP resistor is inside the plug. For portable ICCB (In-Cable Control Boxes), the PP resistor encodes the cable's limit so the vehicle doesn't overdraw.
When the user presses the release button on the plug, the PP circuit changes state. this is how the vehicle knows the user wants to disconnect and can safely release the electronic lock (if equipped).
Wiring specifications
| Parameter | Level 1 | Level 2 |
|---|---|---|
| Voltage | 120V AC (North America) | 208-240V AC |
| Max current | 12A (1.44 kW) or 16A (1.92 kW) | 80A (19.2 kW at 240V) |
| L1 conductor | 12 AWG (3.3 mm2) | 4 AWG (21 mm2) for 80A |
| N conductor | Same as L1 | Same as L1 |
| PE conductor | Same or one size up | Same or one size up |
| CP conductor | 22-18 AWG (0.34-0.82 mm2) | Same |
| PP conductor | 22-18 AWG | Same |
| Cable type | SOOW or equivalent, flexible | EV-rated cable, e.g. Type EV, EVJ, EVE |
| Shielding | Not required | Not required (but CP often shielded) |
| Max cable length | 7.5 m typical (EVSE cord) | 7.5 m typical |
Wire gauge selection
For Level 2, wire gauge depends on the EVSE's rated current:
| EVSE Rating | Continuous Current | Minimum Wire (copper) |
|---|---|---|
| 16A breaker | 12A continuous | 14 AWG (2.08 mm2) |
| 20A breaker | 16A continuous | 12 AWG (3.31 mm2) |
| 30A breaker | 24A continuous | 10 AWG (5.26 mm2) |
| 40A breaker | 32A continuous | 8 AWG (8.37 mm2) |
| 50A breaker | 40A continuous | 6 AWG (13.3 mm2) |
| 60A breaker | 48A continuous | 6 AWG (13.3 mm2) |
| 100A breaker | 80A continuous | 4 AWG (21.2 mm2) |
Remember the 80% rule: continuous loads (EV charging is always continuous) must not exceed 80% of the breaker rating. A 40A EVSE needs a 50A breaker.
Electrical characteristics
Rendering diagram...
- Frequency: 50/60 Hz (works on both)
- Insulation: 600V rated minimum for power conductors
- Temperature rating: 105C minimum for cable insulation
- Contact resistance: < 0.5 mohm at rated current
- Insertion force: 40-80 N (comfortable single-hand operation)
- Durability: 10,000 insertion cycles minimum
Compatibility and adapters
- Type 1 to Type 2: adapter exists (common in Europe for imported US/Japanese cars). Electrically straightforward. just pin remapping. No protocol conversion needed.
- Type 1 to Tesla: Tesla includes a J1772 adapter with every vehicle. Works at full Level 2 power.
- Type 1 to CCS1: not an adapter. CCS1 physically extends Type 1 by adding two DC pins below. A CCS1 vehicle inlet accepts a Type 1 plug for AC charging.
- Type 2 to Type 1: adapter exists for the reverse direction. Less common.
Installation notes
- Mount the EVSE connector holster at 1.0-1.5 m height for accessibility (ADA compliance in the US).
- The cable from EVSE to plug should have a drip loop before the holster. prevents water from running down the cable into the connector.
- Strain relief at the EVSE enclosure is critical. The cable weighs several kg and users yank on it.
- In cold climates, the mechanical latch can freeze. Some EVSEs have heated holsters. At minimum, orient the holster so the connector faces downward to shed water.
- The J1772 connector is not waterproof by itself. IP rating depends on proper mating with the vehicle inlet. The unmated plug sitting in a holster is typically IP44 at best.
Type 1 is the workhorse of North American AC charging. Simple, well-understood, and every EV sold in the US can use it. Its limitation. single-phase AC only, no DC. is why CCS1 was invented as its DC extension.