Type 1 (SAE J1772) is a single-phase, 5-pin AC connector rarely seen on new Singapore installations today. Type 2 (IEC 62196-2, the "Mennekes" connector) is the AC connector Singapore and the wider IEC world standardised on, carrying single or three-phase power through 7 pins. CCS2 (Combo 2, IEC 62196-3) takes the Type 2 shell and adds two large DC pins beneath it, turning the same connector family into a DC fast-charging interface. They are three points on one evolutionary line, and every safety test on a station tests a specific pin, at a specific voltage. Get the connector family wrong and you'll misread an FEV350 or FEV500 result.
What each connector physically is
- Type 1 (SAE J1772): the older single-phase AC connector, historically dominant in North America and Japan. 5 pins: line, neutral, earth, control pilot (CP) and proximity pilot (PP). Single-phase only, capping AC charging around 7.4 kW on a 32 A supply. Singapore's market moved past Type 1 early; the Fluke FEV300 and FEV350 still ship with Type 1 options for the occasional older imported vehicle.
- Type 2 (IEC 62196-2, "Mennekes"): the connector Europe, and Singapore, adopted as the AC standard. 7 pins: three-phase line conductors (L1, L2, L3), neutral (N), protective earth (PE), and the same CP/PP signal pins. Supports AC charging up to 22 kW on a three-phase 32 A supply, and up to 43 kW on some higher-current installations. Fitted to essentially every AC wallbox in Singapore, and what the Fluke FEV350 is built to test.
- CCS2 (Combo 2): Type 2 with an extension: the upper section is the standard 7-pin AC interface; beneath it sits a two-pin DC power block (DC+ and DC-) carrying high current at up to 1000 V DC. A CCS2 inlet accepts both AC charging (upper section) and DC fast charging (full connector). The connector the Fluke FEV500 is built around, and the one Singapore mandates for public DC fast charging.
- CHAdeMO, briefly: a separate DC fast-charging standard, mainly Japanese, using its own connector shape and CAN-bus communication rather than power-line communication. Singapore's EVCA restricts CHAdeMO-only chargers to non-publicly accessible locations.
Pin-by-pin: what each conductor in a Type 2 connector actually does
| Pin | Function | Why it matters for testing |
|---|---|---|
| L1, L2, L3 | Three-phase AC line conductors | Carry charging current once authorised; loop/line impedance and load testing occur here. |
| N | Neutral | Return path for single-phase loads; required for earth fault loop impedance calculation. |
| PE | Protective earth | The safety bond. Every FEV350/FEV500 sequence begins with PE continuity or a PE pre-test before voltage is applied. |
| CP (Control Pilot) | Pilot signalling and PWM duty-cycle communication | Establishes charging state (A–F), signals maximum current via duty cycle, and (in CCS2) carries ISO 15118 / DIN SPEC 70121 communication. |
| PP (Proximity Pilot) | Detects full mating, signals cable current rating | A resistor network tells the EVSE the cable's safe current limit, independent of what CP negotiates. |
The control pilot is the single most tested signal on an AC station, and it's what the Fluke FEV350's auto control pilot function with waveform analysis characterises. The EVSE outputs a 1 kHz square wave on CP at a nominal +12 V / -12 V amplitude; the vehicle moves the pilot through a defined sequence by switching resistors into the circuit: State A (12 V, no vehicle), State B (9 V, connected, not ready), State C (6 V, ready to draw current), State D (3 V, ventilation required, rare in modern EVs). Duty cycle communicates maximum available current (50% signals 30 A). A pilot oscillating unstable between states, with distorted, non-square transitions, points at either a marginal PWM driver or poor contact resistance in the CP path (corroded pin, partially seated connector, damaged wire); the waveform capture, not just the pass/fail flag, tells you which.
Why CCS2 needs both an AC block and a DC block
Vehicle manufacturers needed one inlet accepting both AC charging (home, office, wallbox) and DC fast charging (highway, rapid charger) without two ports. CCS2 keeps the full Type 2 AC pinout intact, unused during DC charging, and adds the DC+ and DC- power pins below for high-current, high-voltage delivery. In a CCS2 DC session the control pilot carries a digital channel over power-line communication (PLC): SLAC (Signal Level Attenuation Characterization) establishes the link, then ISO 15118 or the earlier DIN SPEC 70121 handles negotiation. This is the layer the Fluke FEV500 interrogates, decoding the SLAC handshake and the digital exchange a CCS2 session depends on. A charger that fails to authenticate, negotiate a profile, or drops the link mid-session shows a communication fault here, separate from whether insulation resistance, PE continuity and IMD response pass.
Matching the connector to the test instrument
- Fluke FEV300: test adapter kit with Type 1 and Type 2 plugs, simulating an EV's proximity and control pilot states to exercise an AC station's safety functions without a vehicle, alongside an installation tester (1664 FC) or ScopeMeter (120B).
- Fluke FEV350: all-in-one AC Analyzer for Type 1 and Type 2, to IEC/EN 61851-1 and IEC/HD 60364-7-722. Guided pass/fail sequence: PE earth pre-test, RCD/RDC-DD trip testing, voltage and phase sequence, control pilot waveform analysis, proximity pilot verification, reported through TruTest.
- Fluke FEV500: all-in-one Fast DC Analyzer for CCS2. Acts as a "virtual EV" while verifying ISO 15118/DIN SPEC 70121 communication (SLAC), insulation resistance (IEC 61557-2), PE continuity (IEC 61557-4), IMD response (IEC 61557-8) and residual voltage (IEC 61851-1).
Singapore's connector mandate, in plain terms
Under the Electric Vehicles Charging Act (EVCA), administered by LTA, a charging point seeking approval for a publicly accessible location is restricted to Type 2 AC and/or CCS2 DC connectors. A CHAdeMO-only charger may still be supplied, but only for non-publicly accessible locations (a private residential lot or restricted-access corporate car park). Check this before specification, not after installation.
This mandate sits alongside the technical standard itself. IEC 61851-1 defines the general requirements and charging modes (Mode 1–4) regardless of connector; Singapore's own standard, elevated in 2026 from Technical Reference 25 to Singapore Standard SS 722, sets local safety, RCD, communication and labelling requirements for LTA type approval.
Connector faults an engineer actually sees in the field
- Bent or recessed CP/PP pins: the most common physical failure, from repeated plugging/unplugging by users who don't align the connector carefully. A bent CP pin can read as "vehicle not detected" even though the power conductors mate perfectly.
- Locking mechanism wear: a worn or misaligned lock can make the proximity pilot resistance read outside its expected range, since PP is partly a mechanical continuity check, triggering a fault even when the electrical connection is sound.
- Contact resistance from corrosion or arcing: Singapore's humidity accelerates oxidation on exposed contacts, showing as an unexpectedly high loop impedance or voltage drop under load, well before it's visible as physical damage.
- CCS2 DC pin misalignment: DC+ and DC- carry substantially higher current than the AC pins above them, so the FEV500's autotest checks PE continuity and insulation resistance through the DC pins specifically, rather than assuming the AC-side checks cover the whole connector.
See also our guides to RCD testing and residual current devices and SS 638 electrical installation testing, which cover the fixed wiring feeding these connectors.