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 actually 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 not three competing designs so much as three points on one evolutionary line, and knowing exactly what each pin does is what separates a technician who can read a fault code from one who can only report it.
This matters beyond trivia. Every electrical safety test run on a charging station, from a proximity pilot check to a full CCS2 insulation resistance sweep, is a test of a specific pin, at a specific voltage, following a specific communication protocol. Get the connector family wrong in your head and you'll misread what an FEV350 or FEV500 result is actually telling you.
What each connector physically is
Type 1 (SAE J1772)
Type 1 is the older single-phase AC connector standardised by SAE J1772, historically dominant in North America and Japan. It carries 5 pins: line, neutral, earth, and two small signal pins for control pilot (CP) and proximity pilot (PP). It is single-phase only, which caps practical AC charging power at around 7.4 kW on a 32 A single-phase supply. Singapore's grid and EV market moved past Type 1 early; Unitest still sees it occasionally on older imported vehicles or legacy installations, which is why the Fluke FEV300 test adapter kit and FEV350 analyzer both ship with Type 1 connector options alongside Type 2, precisely to cover this long tail.
Type 2 (IEC 62196-2, "Mennekes")
Type 2 is the connector Europe, and by extension Singapore, adopted as the AC charging standard. It has 7 pins: three-phase line conductors (L1, L2, L3), neutral (N), protective earth (PE), and the same two signal pins, control pilot (CP) and proximity pilot (PP), that Type 1 uses. Because it carries three phases, Type 2 supports AC charging up to 22 kW on a standard three-phase 32 A supply, and up to 43 kW on some higher-current three-phase installations, versus Type 1's single-phase ceiling. This is the connector fitted to essentially every AC wallbox and public AC charging point installed in Singapore today, and it is what the Fluke FEV350 is built to test.
CCS2 (Combination Charging System, Combo 2)
CCS2 is not a separate connector family so much as Type 2 with an extension. The upper section is the standard Type 2 7-pin AC interface. Beneath it sits a two-pin DC power block (DC+ and DC-) capable of carrying high current at up to 1000 V DC. A vehicle with a CCS2 inlet can accept both AC charging (using only the upper Type 2 section) and DC fast charging (using the full combined connector), which is exactly what "Combo" refers to. This is the connector the Fluke FEV500 is designed around, and it is the connector Singapore's regulatory framework mandates for public DC fast charging.
CHAdeMO, briefly
CHAdeMO is a separate DC fast-charging standard, mainly associated with Japanese manufacturers, using its own connector shape and its own CAN-bus based communication protocol rather than CCS2's power-line communication. Singapore's Electric Vehicles Charging Act (EVCA), administered by LTA, restricts CHAdeMO-only chargers (units without a Type 2 or CCS2 connector) to non-publicly accessible locations. Publicly accessible charging infrastructure in Singapore is limited to Type 2 AC and/or Combo 2 (CCS2) DC connectors. If you're commissioning or testing a charger destined for a public car park, CHAdeMO compatibility alone will not satisfy the location-approval requirement.
Pin-by-pin: what each conductor in a Type 2 connector actually does
Understanding the pinout is the difference between reading a fault code and understanding it. Here is what each pin in a Type 2 connector carries, and why it exists:
| Pin | Function | Why it matters for testing |
|---|---|---|
| L1, L2, L3 | Three-phase AC line conductors | Carry the actual charging current once authorised. Loop/line impedance and load testing occur here. |
| N | Neutral | Return path for single-phase loads drawn from any one line. Required for correct earth fault loop impedance calculation. |
| PE | Protective earth | The safety bond. Every FEV350/FEV500 test sequence begins with a PE continuity or PE pre-test before any voltage is applied. |
| CP (Control Pilot) | Pilot signalling and PWM duty-cycle communication between EVSE and vehicle | Establishes charging state (A through F), signals maximum available current via duty cycle, and (in CCS2) carries digital ISO 15118 / DIN SPEC 70121 communication. |
| PP (Proximity Pilot) | Detects that the connector is fully mated and signals cable current rating | A resistor network in the cable or vehicle inlet tells the EVSE the maximum current the cable itself can safely carry, independent of what the CP negotiates. |
The control pilot is worth dwelling on because it is the single most tested signal on an AC charging station, and it is exactly what the Fluke FEV350's auto control pilot function with waveform analysis is built to characterise. The EVSE outputs a 1 kHz square wave on CP at a nominal +12 V / -12 V amplitude. The vehicle, once connected, changes the DC offset of that signal by switching resistors into the circuit, moving the pilot voltage through a defined sequence: State A (12 V, no vehicle connected), State B (9 V, vehicle connected, not ready to charge), State C (6 V, vehicle connected and ready to draw current), and State D (3 V, ventilation required, rare in modern EVs). The EVSE reads the duty cycle of the PWM waveform to communicate the maximum current it can supply, for example a 50% duty cycle signals 30 A available, while the vehicle's own charging controller decides how much of that it actually draws.
A worked scenario makes this concrete. Say an FEV350 test on a newly commissioned Type 2 AC charger reports a control pilot state that oscillates unstable between State B and State C rather than settling cleanly, with waveform analysis showing distorted or non-square pilot transitions. That reading points at a specific electrical cause: either a marginal PWM signal driver in the EVSE losing drive strength under load, or a poor contact resistance somewhere in the CP signal path (a corroded pin, a partially seated connector, or a damaged pilot wire in the cable) introducing enough voltage drop or noise to corrupt the clean square wave the vehicle's controller expects. A pass/fail result alone tells you something is wrong; the waveform capture tells you where to start looking.
Why CCS2 needs both an AC block and a DC block
The combo design exists because vehicle manufacturers needed one inlet that could accept both AC charging (at home, at the office, at a shopping centre wallbox) and DC fast charging (on a highway, at a public rapid charger) without requiring two separate ports on the car. CCS2 solves this by keeping the full Type 2 AC pinout intact in the upper section, unused during DC charging, and adding the DC+ and DC- power pins below for high-current, high-voltage direct current delivery.
Critically, the control pilot pin does more work in a CCS2 DC session than in a standard AC session. Rather than just PWM signalling of available current, CCS2's control pilot carries a full digital communication channel over power-line communication (PLC), using the SLAC (Signal Level Attenuation Characterization) protocol to establish the physical link, followed by ISO 15118 (the international standard for vehicle-to-grid digital communication) or the earlier DIN SPEC 70121 protocol for basic DC fast-charging negotiation. This is exactly the layer the Fluke FEV500 is built to interrogate. Where the FEV350 tests an AC control pilot's analogue PWM behaviour, the FEV500 additionally decodes and verifies the SLAC handshake and the ISO 15118 / DIN SPEC 70121 digital exchange that a CCS2 DC session depends on before it will ever deliver current. A charger that fails to authenticate, fails to negotiate a charging profile correctly, or drops the digital link mid-session will show up in FEV500 diagnostics as a communication fault at this layer, entirely separate from whether the underlying electrical safety measurements (insulation resistance, PE continuity, insulation monitoring device response) pass.
Matching the connector to the test instrument
Because the connector families map so directly onto Unitest's product range, it is worth stating plainly which instrument covers which interface:
- Fluke FEV300: a test adapter kit supplied with both Type 1 and Type 2 connector plugs. It simulates an electric vehicle's proximity pilot and control pilot states so a technician can exercise an AC charging station's safety functions (including CP error and PE earth fault simulation) without an actual vehicle on site, working in combination with a Fluke installation tester (such as the 1664 FC) or ScopeMeter (such as the 120B Series) for the underlying electrical measurements.
- Fluke FEV350: an all-in-one AC EV Charging Station Analyzer for Type 1 and Type 2 connectors, designed to IEC/EN 61851-1 and IEC/HD 60364-7-722. It runs a guided, pass/fail test sequence covering PE earth pre-test, 30 mA RCD plus 6 mA RDC-DD trip testing, nominal voltage and phase sequence, automatic control pilot testing with waveform analysis, proximity pilot verification, and error condition testing, all reported through TruTest software.
- Fluke FEV500: an all-in-one Fast DC EV Charging Station Analyzer built specifically around the CCS2 connector. It acts as a "virtual EV," drawing a controlled load (typically around 2 kW) through the CCS2 interface while verifying ISO 15118 / DIN SPEC 70121 communication (including SLAC), insulation resistance (RISO, DC+ to PE and DC- to PE, selectable 500 V or 1000 V test voltage per IEC 61557-2), PE continuity (RLO, up to 10 A per IEC 61557-4), insulation monitoring device response (IEC 61557-8), and residual voltage per IEC 61851-1, all without an actual EV or a physical connection to the mains supply beyond the CCS2 outlet itself.
Singapore's connector mandate, in plain terms
Two separate regulatory tracks touch a Singapore EV charger, and connector choice sits inside the LTA-administered one. Under the Electric Vehicles Charging Act (EVCA), a charging point seeking approval for a publicly accessible location is restricted to Type 2 AC and/or Combo 2 (CCS2) DC connectors. A charger with only a CHAdeMO connector may still be supplied and installed, but only for non-publicly accessible locations, such as a private residential lot or a restricted-access corporate car park not open to the general public. This is worth checking before specification, not after installation: a facility that installs a CHAdeMO-only fast charger intending to serve visitor parking will find that charger cannot legally receive non-restricted-access approval.
This mandate sits alongside, not instead of, the technical charging standard itself. IEC 61851-1 defines the general requirements for conductive EV charging systems and the charging modes (Mode 1 through Mode 4) that apply regardless of connector type; Singapore's own national charging standard, elevated in 2026 from Technical Reference 25 (TR25:2022) to Singapore Standard SS 722, sets the local safety, RCD, communication and labelling requirements a charger must meet for LTA type approval, on top of whatever international connector standard it physically uses.
Connector faults an engineer actually sees in the field
- Bent or recessed CP/PP pins: because these are small signal pins compared to the power conductors, repeated plugging and unplugging, especially by end users who don't align the connector carefully, is the single most common physical failure point. A bent CP pin can produce an intermittent or absent pilot signal that reads as "vehicle not detected" even though the power conductors mate perfectly.
- Locking mechanism wear: Type 2 and CCS2 connectors both use a mechanical lock to prevent the cable being pulled during charging. A worn or misaligned lock can cause the proximity pilot resistance value to read outside its expected range, since PP is partly a mechanical continuity check, triggering a fault even when the electrical connection itself is sound.
- Contact resistance from corrosion or repeated arcing: Singapore's humidity accelerates oxidation on any exposed contact surface not rated for the environment. Elevated contact resistance on the AC line pins will show up as an unexpectedly high loop impedance or voltage drop reading under load, well before it becomes visible as physical damage.
- CCS2 DC pin misalignment: the DC+ and DC- pins on a CCS2 connector carry substantially higher current than the AC pins above them. Any misalignment here has a proportionally larger safety consequence, which is why FEV500's guided autotest sequence checks PE continuity and insulation resistance through the DC pins specifically, rather than assuming the AC-side checks cover the whole connector.
For a broader look at how RCD protection interacts with connector type and charging mode, see our guide to RCD testing and residual current devices, and for the general Singapore electrical installation code that underpins the fixed wiring feeding any of these connectors, see our SS 638 electrical installation testing guide.