240 kW DC Fast Charger: Grid Connection, Cooling and Cable Choices

Short answer: a 240 kW dual-connector DC charger is a two-car machine. With standard 200 A CCS cables, a 400 V-class car peaks at about 80 kW and an 800 V-class car at about 160 kW, so one of each — or two 800 V cars at about 120 kW each — keeps the whole 240 kW busy. Each unit needs about 258 kVA of supply (372 A per phase at 400 V), which usually means a dedicated transformer. It pays off on motorway service areas, busy city hubs and fleet sites with quick turnarounds.

How 240 kW is shared between two cars

The rule behind the chart is simple: power = current × battery voltage. A 200 A cable on a car whose battery sits around 400 V carries about 80 kW; on a car around 800 V it carries about 160 kW. The cabinet adds the two connectors together up to its 240 kW limit.

Situation	Connector A	Connector B	Cabinet used
One 400 V-class car	≈ 80 kW	—	⅓
One 800 V-class car	≈ 160 kW	—	⅔
One 400 V + one 800 V car	≈ 80 kW	≈ 160 kW	All
Two 800 V-class cars	≈ 120 kW	≈ 120 kW	All
Two 400 V-class cars	≈ 80 kW	≈ 80 kW	⅔

Charging times

Vehicle and situation	Typical average, 10 → 80 %	60 kWh battery	80 kWh battery
400 V-class car	≈ 65–70 kW	≈ 35 min	≈ 50 min
800 V-class car, alone or next to a 400 V car	≈ 120–140 kW	≈ 18–20 min	≈ 24–28 min
800 V-class car, next to another 800 V car	≈ 100–110 kW	≈ 22 min	≈ 30–34 min

Estimates; the car’s charging curve, battery temperature and starting charge decide the real time — see why a 150 kW charger rarely delivers 150 kW.

Grid connection

Item	VT-DF240 (IEC)	VT-DF240-NA
Supply	230 / 400 V AC, 3-phase, 50/60 Hz	480 V AC 3P+N+PE, 60 Hz
Input current per phase	Up to 372 A	Up to 310 A
Apparent power	≈ 258 kVA	≈ 258 kVA
Typical feed for one unit	Dedicated transformer around 315 kVA, or spare capacity on a larger one	Dedicated service and transformer per utility rules
Two units	≈ 516 kVA — a 630 kVA transformer leaves little margin for other loads; use load management	Same principle

Three things decide the project budget more than the charger price:

1. Transformer and medium-voltage connection — lead times can be longer than the charger’s production time. Apply early.
2. Demand charges — two 240 kW units can set a peak of nearly 500 kW even with low daily use. Site-level load management can cap it; see demand charges explained.
3. Cable route and protection — 372 A per phase needs large conductors and a properly coordinated breaker; the electrician sizes them from the input current, not from the 240 kW label.

Cooling and cables

The VT-DF240 is forced-air cooled: fans draw air through filtered intakes across the power modules and out of the cabinet. That keeps the design simple and serviceable, with two practical consequences:

Topic	What to plan
Clearance	Keep the air paths free — follow the clearances in the installation manual, especially when placing units back to back
Dust and heat	Clean or replace filters on a schedule; in desert or roadside sites, check them more often
Cable	200 A air-cooled CCS cables, 6 m standard, custom lengths available. The cable current, together with the car’s battery voltage, sets single-car speed
Noise	< 65 dB — consider placement near homes or hotel rooms

Where 240 kW pays off

Site	Why 240 kW
Motorway service areas	High traffic, a growing share of 800 V cars, two bays per cabinet
Busy city hubs	Ride-hailing, taxis and private cars mixing 400 V and 800 V
Fleet sites with short turnarounds	Two vehicles charging fast between shifts
Fuel station forecourts with space for one large cabinet	Two fast bays from one footprint

In the EU, AFIR requires charging pools every 60 km on the TEN-T core network with at least 400 kW total output and at least one 150 kW point from the end of 2025, rising to 600 kW and two 150 kW points by the end of 2027. Two 240 kW units (480 kW) meet the 2025 pool level; a third unit, or a mix with 160–300 kW cabinets, reaches the 2027 level.

For sites with mostly 400 V cars, 160 kW already lets two of them charge at full speed. For heavy vehicles and the highest-traffic hubs in North America, see 360 kW.

VT-DF240 specifications

	VT-DF240 (IEC)	VT-DF240-NA
Max. output power	240 kW	240 kW
Output voltage	150–1,000 V DC	200–1,000 V DC
Connectors	CCS2 + CCS2 or CCS2 + CHAdeMO	CCS1, NACS, CHAdeMO options
Max. current	CCS up to 200 A; CHAdeMO 150 A	CCS1 up to 200 A; CHAdeMO 150 A
Efficiency	≥ 95.2 % at full load	≥ 95.2 % at full load
Enclosure	IP54 · IK10	NEMA Type 3R · IK10
Operating temperature	−20 °C to +55 °C	−25 °C to +55 °C
Interface	7″ touchscreen, RFID, QR code; OCPP 1.6J / 2.0.1	Same
Footprint (W × D × H)	850 × 840 × 1,850 mm (plus 115 mm cable hanger)	Same
Options	21″ advertising screen, POS payment, 22 kW AC output, 4G, C4 anti-corrosion finish	Advertising screen, POS payment, 4G

See the VT-DF product page for the full range.