Refrigerated containers
Reefer container power cables and plugs
A refrigerated container keeps its cargo safe only while it has power. The lead and plug that deliver that power are handled roughly, dragged across quays and decks, and exposed to salt water. They deserve a better specification than they usually get.
How a reefer is powered
Refrigerated ISO containers, covered by ISO 1496-2 for thermal containers, carry their own refrigeration unit. That unit runs on three-phase AC supplied by the ship, the terminal's reefer racks, a clip-on generator set or a depot supply. The unit carries its own power lead, stored on the container when not in use, and ending in an industrial plug.
Most reefer units use a four-pin (three-phase plus earth), 32 A plug from the IEC 60309 industrial plug family, colour-coded red for the 380–480 V range. IEC 60309 plugs are keyed by the position of the earth contact as well as by colour. Always confirm the voltage range, rating and earth-contact position against the refrigeration unit maker's documentation and the receptacles at your terminals before ordering replacements.
How reefer leads fail
- Crushed or cut jackets from handling equipment, lashing gear and container doors.
- Damaged plugs that are dropped, dragged or left unplugged on the ground, with bent pins, cracked housings and failed seals.
- Water in the plug when the cover is left open or the gland seal has hardened, leading to corrosion and tripped supplies.
- Pulled terminations where the lead has been yanked out by the cable instead of the plug, and the strain relief has let go.
- Jackets hardened or cracked by sunlight, cold and repeated coiling.
A failed lead can mean a warm container and a cargo claim, so leads and plugs are inspected at every pre-trip inspection (PTI). Damaged leads should be replaced, not taped.
Specifying a replacement lead
| Item | What to specify |
|---|---|
| Cable type | Heavy-duty flexible cable rated for outdoor and marine exposure, with an oil- and weather-resistant jacket. Rubber-insulated flexible cable such as the H07RN-F type is widely used, but follow the unit maker's specification. |
| Conductors | Three phases plus earth, sized for the unit's current and the lead length. |
| Length | Match the original so it reaches rack receptacles in every stowage position, without leaving excess cable to be damaged. |
| Plug | Same IEC 60309 rating, voltage colour and earth position as the terminal and ship receptacles, with a watertight rating suitable for exposed use. |
| Unit end | The termination method and gland specified by the refrigeration unit maker. |
| Strain relief | At both ends, rated for the pull the lead will actually see. |
| Test | Continuity, correct phase-to-pin order, earth continuity and insulation resistance on every lead. |
| Identification | Part number and date, so leads that fail early can be traced to a batch. |
Extension leads and depot wiring
Depots and cold-storage yards often build their own extension leads and distribution boards for reefer plug-in areas. These are fixed or semi-fixed electrical installations. They must be designed and inspected by a qualified electrician to the local wiring regulations. Buy the leads to the same specification as above, and never join two leads with an unsealed coupling on the ground.
Tracking the leads themselves. Operators that log lead replacements against container numbers spot problem stowage positions and handling practices quickly. It is a small maintenance record that pays for itself, and exactly the kind of per-unit history Cargovate keeps alongside the container's movements.
Last reviewed 2026-09-17