240 kW DC Charger: Power Sharing, Site Fit and RFQ Guide

Quick answer

A 240 kW DC charger is a rated total-power class, not a promise that every connected vehicle will receive 240 kW. Actual delivery is limited by the ordered cabinet and connector configuration, the vehicle’s voltage and current request, concurrent-session allocation, thermal conditions, site capacity and control settings. Before comparing prices, freeze those boundaries in one configuration record and define how they will be witnessed at FAT and SAT.

For procurement, the most useful question is not “Is this a 240 kW charger?” It is: What exact output can this ordered configuration deliver to each active connector, under which vehicle, environmental and site conditions, and what evidence will prove it?

What does 240 kW mean on a DC charger?

The number normally describes a rated power boundary somewhere in the charging system. Depending on the product architecture, that boundary may belong to an all-in-one charger, a power cabinet, or a cabinet feeding one or more dispensers. It does not automatically define the result at every cable.

Separate these terms in every proposal:

This distinction prevents the most common RFQ error: treating a cabinet headline as a per-vehicle guarantee.

Build a 240 kW Delivery Contract before comparing suppliers

The 240 kW Delivery Contract is a one-page technical schedule. It is not a commercial warranty by itself. It is the configuration truth that the quotation, drawing, software setup and acceptance test must all reference.

1. Conversion boundary

State what the 240 kW rating belongs to. Is it one integrated unit, one cabinet, a shared cabinet group or a station-level managed limit? Record the exact model and option code. A family brochure is useful for discovery, but it cannot replace an order-specific line item.

2. Output envelope

Request the allowed DC voltage and current ranges, the constant-power region if applicable, and any current or power derating conditions. Do not copy these fields from another rating in the same family. Each ordered configuration needs its own controlled sheet.

3. Connector boundary

Freeze connector standard, connector count, cable length, cable-current limit, cooling method if relevant and any cable-management hardware. A site cannot validate vehicle fit from power alone.

4. Allocation rule

Define the single-session ceiling, two-session combinations, minimum allocation step, priority behavior and what happens when a session starts or stops. If the proposal says “dynamic sharing,” require a numerical table. The adjective is not the rule.

5. Active derating and control limits

List environmental derating, thermal protection, site demand limits, CSMS charging profiles and local-controller setpoints. These limits should have owners. A supplier cannot control a utility restriction, and a site integrator should not silently change the ordered equipment envelope.

6. Witness condition

Define the load, starting conditions, duration, measurement points, permitted tolerance and record format for FAT and SAT. A screenshot of a momentary peak is not the same as a sustained test with known voltage and current.

The contract works only if all six lines use the same configuration identifier. If the quotation, drawing and FAT sheet name different variants, stop the review and reconcile them.

Why a vehicle may draw less than 240 kW

DC output follows the basic relationship:

Power (kW) = Voltage (V) × Current (A) ÷ 1,000

The equation is simple. The active limits are not. A vehicle asks for voltage and current according to its battery state, temperature, charging curve and internal controls. The charger can only respond within its own connector and conversion envelope. Concurrent allocation or a site-level limit can reduce the available ceiling again.

For example, a planning calculation at 400 V would require 600 A to reach 240 kW. At 800 V, it would require 300 A. Those figures are arithmetic illustrations, not HG Power product specifications. They show why “240 kW” without a voltage-current envelope is incomplete.

Use a lowest-limit model:

Delivered power ≤ minimum of vehicle request, connector envelope, allocated cabinet power, thermal limit, site limit and control limit

This model also explains why a larger charger does not create a faster session for every vehicle. The charger rating removes one possible bottleneck; it does not remove the other ceilings.

Does a dual-connector 240 kW charger provide 2 × 120 kW?

Possibly, but never assume it.

Two connectors can be implemented in several ways. One session may be allowed to use most or all of the available pool. Two active sessions may split the pool equally, follow vehicle demand, preserve a minimum allocation, or obey a priority rule. A configuration may also have cable-current limits that make the practical combinations asymmetric.

The phrase “dual connector” proves only that there are two connection paths. The phrase “dynamic load balancing” still does not state the allocation table. Ask for at least these rows:

The purpose is not to force one “correct” sharing philosophy. It is to make the purchased behavior visible and testable.

For a deeper explanation of generic allocation architectures, use the Dual Gun Charging guide. The 240 kW page keeps its focus on the exact ordered result.

When is 240 kW a reasonable project candidate?

A 240 kW option becomes credible when the duty model can use it and the site can support it. Start with operating data, not a generic site label.

Calculate the energy-window baseline

For one vehicle group:

Average required power = energy required in the window ÷ usable charging hours

If a fleet needs 720 kWh delivered across a six-hour window, the arithmetic baseline is 120 kW before considering charging losses, arrival overlap, vehicle acceptance, reserve capacity or operational disruption. This does not mean a 120 kW charger is sufficient, nor that a 240 kW charger is necessary. It identifies the first constraint to model.

Then add:

• arrival and departure distributions, not only daily totals;
• number of vehicles that may need service at the same time;
• each vehicle group’s voltage, connector and charging-curve behavior;
• required recovery after late arrivals or route disruption;
• planned utilisation today and credible growth;
• maintenance and fault-containment strategy;
• available site capacity and demand-management rules.

Use conditions, not labels

If the model cannot state energy per window, vehicle groups and concurrency, it is too early to choose the charger rating.

Site fit: turn 240 kW into an input load ledger

The DC rating is not the AC service requirement. The site engineer needs the exact equipment input data, conversion efficiency assumptions, auxiliary loads, diversity policy and local design requirements. Do not derive a transformer size from 240 kW alone.

Build a load ledger with these fields:

1. Ordered charger model and maximum AC input from its controlled sheet.
2. Number of chargers and the maximum coincident operating case.
3. Auxiliary loads, including cooling, lighting, payment, communications and enclosure systems where applicable.
4. Other site loads sharing the service.
5. Local-controller or CSMS demand limit and the failure-state rule.
6. Existing service, transformer, switchgear and protection data.
7. Utility capacity, interconnection process and metering requirements.
8. Future expansion allowance that the owner has actually approved.

The US Department of Energy notes that requested site capacity, grid upgrades, site conditions and local processes can materially affect energisation. That principle travels even when the project is outside the United States: the responsible utility, engineer and authority having jurisdiction define the local path.

The equipment supplier should provide the ordered unit’s input boundary and interface requirements. The local electrical designer should determine conductor, protection, transformer, earthing and code compliance. The owner should approve the operational demand limit. Keep these responsibilities explicit.

Power sharing is not the same as OCPP smart charging

Three control layers are often collapsed into one phrase:

1. Internal power allocation routes the charger’s available conversion capacity among active outputs.
2. Local site control keeps one or more chargers within a site demand limit or energy-management objective.
3. CSMS/OCPP control exchanges charging profiles, status and transaction data between charging stations and the management system.

OCPP 1.6 includes smart-charging support, and later versions add functions. That does not prove that a specific charger, firmware version and CSMS combination implements the required profiles correctly. It also does not prove the internal connector-allocation rule.

Freeze the following in the integration schedule:

• OCPP version and transport;
• required functional profiles or use cases;
• charger firmware and CSMS release;
• local/offline behavior;
• limit precedence when cabinet, site and CSMS commands disagree;
• cybersecurity and credential responsibility;
• test cases, logs and acceptance owner.

If certification is required, verify the exact product designation, software version and profile scope. “OCPP compatible” is not a certificate identifier.

Cooling and sustained duty: ask for a test, not an adjective

The need for a particular cable or cabinet cooling design depends on current, cable construction, ambient conditions, duty cycle and the product architecture. Do not assume that every 240 kW configuration is air-cooled or liquid-cooled. Do not use the cooling label as a proxy for sustained output.

Request an order-specific thermal schedule:

• cooling method by cabinet and cable;
• ambient and altitude range;
• power/current derating curve;
• inlet/outlet airflow or coolant-service requirements;
• filter, fan, pump or coolant maintenance tasks where applicable;
• alarm and protective-action sequence;
• defined sustained-load FAT case;
• site clearances and heat-rejection assumptions.

The acceptance record should state the load voltage, current, duration and environmental conditions. Without those fields, two “240 kW” test reports may describe different stress levels.

Make 240 kW quotations comparable

A low equipment price may exclude work that another supplier includes. Normalise every proposal into five layers:

Ask each bidder to return an assumptions-and-exclusions register. A blank field is not an agreement. It is an unresolved commercial or technical boundary.

For supplier verification beyond this project configuration, use the DC charger manufacturer audit guide.

FAT and SAT for a 240 kW project

FAT and SAT answer different questions.

Factory acceptance testing should confirm the built configuration before shipment. The record should identify the unit, firmware, connector options, protection settings and output test conditions. Where full-power factory loading is part of the contract, define the load bank or simulator, duration, measurement points and tolerance.

Site acceptance testing should confirm installation interfaces and integrated behavior at the destination. It may include energisation checks, communication with the CSMS, authentication/payment flow, site demand limits, emergency actions, session start/stop and the agreed single-/two-session cases. Local electrical and safety sign-off remains with the responsible parties.

Use one traceability chain:

RFQ requirement → ordered configuration → approved drawing → FAT step → shipment identity → SAT step → signed exception/closure

Do not close an exception by replacing a failed requirement with a new verbal interpretation. Record the change, responsible party and acceptance basis.

The 12-input RFQ for a 240 kW DC charger

Provide these inputs before asking for a final configuration and price:

1. Destination country, installation address and responsible local standards path.
2. Site type, operating hours and target commissioning window.
3. Vehicle models or, when unknown, voltage/current/connector envelopes.
4. Energy required per vehicle group and usable charging window.
5. Expected arrivals, dwell time and concurrent-session cases.
6. Required connector standard, count, cable length and cable-management needs.
7. Required one-session and two-session behavior.
8. Available AC supply, utility status and maximum site demand.
9. Ambient temperature, altitude, dust, humidity, salt or other environmental exposure.
10. CSMS, OCPP, payment, networking and offline requirements.
11. Equipment, installation, commissioning, training, spares and warranty scope split.
12. FAT/SAT cases, documents, instruments, tolerances and sign-off parties.

The supplier should return the exact model/options, controlled data sheet, allocation table, input interface, general arrangement, evidence index, assumptions/exclusions and commercial scope against those inputs.

Do not choose 240 kW yet if…

• the 240 kW boundary is not tied to an exact configuration;
• vehicle voltage/current and connector requirements are unknown;
• the proposal does not state single- and concurrent-session behavior;
• the utility/site-capacity path has not begun;
• cooling and derating are described only with marketing adjectives;
• OCPP requirements are a version label without use cases;
• destination evidence is assumed from a family certificate;
• FAT/SAT has no defined load, duration, tolerance or record;
• competing prices include different site, software or delivery scopes.

These are not reasons to reject 240 kW. They are reasons to finish the engineering definition before committing capital.

Frequently asked questions

Can a 240 kW charger charge two vehicles at 120 kW each?

Only if the ordered configuration’s connector envelopes, allocation rule and active site/thermal limits allow that combination. Request a numerical two-session matrix and a witnessed test. Do not infer 2 × 120 kW from “240 kW dual connector.”

How fast will a 240 kW DC charger charge an EV?

There is no universal time. Battery energy needed, vehicle acceptance curve, state of charge, temperature, voltage/current limits, concurrency and losses all matter. Use the electric-car charging-time guide for the calculation framework.

What transformer size is required for a 240 kW charger?

The charger’s DC rating alone is insufficient. The local engineer needs the exact AC input data, efficiency/auxiliary assumptions, number of chargers, coincidence, other site loads, demand controls, expansion plan and local electrical requirements.

Is 240 kW considered HPC?

There is no single procurement result created by the label “HPC.” Define the voltage, current, connector/cable thermal envelope, sustained duty and evidence required for the project. See HPC vs DC charging for the terminology boundary.

Does OCPP control how 240 kW is split between two cables?

Not necessarily. OCPP can carry charging profiles and site-management commands, while internal cabinet logic may allocate power between connectors. Specify both layers and test their interaction.

What evidence should accompany a 240 kW order?

At minimum: exact configuration sheet, drawing, connector and voltage-current schedule, allocation matrix, AC interface, environmental/derating data, applicable document index, software scope, FAT procedure/results and SAT plan.

Turn the rating into a testable configuration

HG Power’s public DC portfolio context spans 40–480 kW, and the reviewed CCS1 manual includes a named 240 kW family model. Final specifications still depend on the selected configuration and destination.

For a useful review, send the 12 RFQ inputs above. HG Power can then respond with an exact configuration boundary, evidence list, assumptions/exclusions register and acceptance scope instead of treating “240 kW” as a complete specification.