Electrical Design

This section provides electrical design guidelines for Express Solo.

Electrical Supply Requirements

EV Electric Vehicle charging equipment operates as a continuous load, drawing high current for extended periods. Branch-circuit conductors and protective devices must therefore be sized in accordance with applicable local electrical regulations for continuous‑load operation.

When planning multiple EV Electric Vehicle charging stations, it is best practice to segment non-continuous and continuous loads, with all branch circuits for EV Electric Vehicle charging on a dedicated electrical panel assembly with adequate circuit breakers. When sizing new electrical panels dedicated for EV Electric Vehicle charging, all branch circuits must support continuous load.

Express Solo is available in multiple power ratings: 350 kW, 500 kW, 525 kW

Each Express Solo requires its own circuit breaker. Recommended breaker sizing is given below. Check with local code for breaker size requirements.

Recommended breaker size for the Europe region (400 V AC):

400 V AC Recommended Breaker Size

Max. Output Power	AC Continuous Input Current Rating	Recommended breaker size
Max. output power 350 kW	542 A	600 A
Max. output power 500 kW	789 A	800 A
Max. output power 525 kW	800 A	900 A

Express Solo is tested to IEC 61000-4-5, Level 5 (6 kV @ 3000 A) standards.

Disconnect and Emergency Shutoff

Express Solo ships with an AC disconnect switch for emergency shutoff. The switch is located on the intake side of the Express Solo cabinet.

Transformer Configuration

Refer to the following table for the transformer configuration.

Transformer Configuration

Parameter	Transformer Configuration
Input rating	400 V AC, 3-phase, 850 A, 50 Hz
Electrical service configuration	400 V AC 3-phase grounded WYE (Y) configuration   400 V AC 3-phase Delta (D) configuration (corner-grounded Delta transformer) is not acceptable
Product connection	Express Solo must be connected to L1, L2, and L3 (neutral not required)

Shunt Trip Wiring (optional)

Express Solo provides a set of unpowered (dry) contacts to connect to an optional shunt trip device. These contacts are rated to 240 VAC and 6 amps.

Wiring sections to and from Express Solo are deactivated when unsafe conditions are detected, such as unintended cover panel removal. A breaker reset is required any time the shunt trip is activated.

If installed, each Express Solo must be wired to the shunt trip unit of its own upstream circuit breaker. Upstream AC power must be shut off at the panel to remove shock risk inside the Express Solo. All shunt trip behavior is already hard-coded into the Express Solo and has no programmable variables.

Emergency stop devices are governed by local and regional codes and may be required in some sites. If one is required by code or by the site, confirm specifications with your ChargePoint representative.

1. Electrical panel

2. Express Solo

3. Control voltage supply, maximum 240 VAC

4. Shunt trip circuit breaker

5. Shunt trip coil

6. Auxiliary contacts (closed when main contacts are closed)

7. 3-phase AC main

8. Express Solo shunt trip contacts, Normally Open (inside the auxiliary power supply, accessible on field wiring terminal block)

9. 3-phase Express Solo AC input

Grounding Requirements

Soft Shutdown

The soft shutdown function is an optional feature that can be installed as a way to stop a charge session on an Express Solo. It is not meant to safely service the Express Solo or take the place of an AC disconnect switch.

To use this feature, the installer must select and mount a physical soft shutdown switch (one per Express Solo) with the following specifications:

• Building wire rated to 600 V and suitable for the installation environment (e.g., dry, damp, or wet locations)

• Normally Open (NO) configuration

• Switch current of 2 mA

• Switch voltage of 48 V

• Gold contacts suggested

When creating the site drawings, consider where any soft shutdown switches should be positioned. If applicable, consider disability and accessibility regulations for your region when choosing switch locations.

When the switch is closed, the Express Solo software ends the current charging session with a normal stop, then opens DC contactors in the Express Solo. The station stays in this state regardless of station power, not allowing operation. Only a service technician can place the Express Solo back into service after the switch is reset to Open.

Hardwire Ethernet

As an option, Express Solo supports hardwire Ethernet connection to an external network server. The connection requires a conduit for the Ethernet cable, which must be run from the customer server or network equipment directly to Express Solo. The connection is installed in only one Express Solo within an Express cluster, providing network connection for every node in the cluster

Safety Hub

Safety Hub is an Express Solo feature that provides continuous electrical-isolation monitoring to enhance system safety. When required, Safety Hub uses a dedicated twisted-pair connection routed from the Express Solo Safety Hub Board to each associated Power Link. These conductors may share the same conduit as the 48 V DC and Ethernet wires serving the Power Links.

Safety Hub wiring requirements vary by Power Link model. Depending on the specific Power Link used in the installation, one of the following configurations will apply:

• Some Power Link models require a direct Safety Hub twisted-pair connection between the Express Solo Safety Hub Board and the Power Link.

• Other Power Link models do not require a Safety Hub wire connection. For these models, a jumper wire must be installed on the Express Solo Safety Hub Board instead of running twisted-pair wiring to the Power Link. This jumper is supplied with the Power Link and does not need to be sourced separately. Installation details are provided in the Express Solo Installation Guide.

Refer to the site design guide and installation guide of the Power Link model specific to your project to determine whether Safety Hub twisted wire connection is required.

Wiring and Conduit Requirements

Refer to the Express Solo Datasheet at ChargePoint Product Reference Documentation for full product specifications.

Ensure that the installation location is equipped with service wiring that support the station's power requirements.

Conduit and wire size are determined based on current. Service wiring in conduit or armored cable must be run as required to comply with local electrical codes. Consult national and local codes or a project engineer to determine the grade, quality, and size of the conduit or cable.

Wire Run Lengths

Wire run length guidelines are given below:

• The maximum total external DC output wire run length from an Express Solo to a paired EVSE Electric Vehicle Supply Equipment (such as a Power Link 2000 or another Express Solo) must not exceed 200 m (656 ft). Refer to the cluster configuration provided by ChargePoint for interconnect details.

• 48 V DC wire and Ethernet run length between Express Solo and any Power Link must not exceed 200 m (656 ft). At minimum, there must be one 48 V DC wire pair connecting from the Express Solo to each Power Link. If the distance between the Express Solo and a Power Link exceeds 100 m (328 ft), contact ChargePoint to determine if an additional 48 V DC wire pair must be run to compensate for voltage drop.

• The maximum wire run length between an Express Solo and an external network connection is 200 m (656 ft).

Ethernet Cable Type and Configuration

Specifications for Ethernet cable type and configuration are given below:

• For Ethernet communications between any two nodes (for example, between an Express Solo and a Power Link) or to an external network connection:

  • For distances up to 100 m (328 ft): use outdoor-rated Cat6 Shielded Twisted Pair (STP Shielded Twisted Pair) cable. Lesser grades of cable do not provide the required noise immunity.

  • For distances between 100 m (328 ft) and 200 m (656 ft): use extended-reach cable rated for 200 m (656 ft).

• An Ethernet cable connecting between an Express Solo and a Power Link must have the shield terminated at the Express Solo end of the cable, not at the Power Link end.

• For an Ethernet cable connecting between two Express Solos, terminate the shield at only one end of the cable. The Express Solo with the terminated cable end is designated as the main unit within the cluster.

Conduit Requirements

In regions that use conduits, wire conduits may enter Express Solo through a Concrete Mount Template or through a skid via conduit stub-ups. In regions that do not use conduits and/or use armored cables, the cables may be laid per the conduit layout defined by the CMT.

If using conduits:

• Conduits must be sealed to maintain a Pollution Degree 2 environment.

• Conduits must not have bell ends. Conduits with bell ends may interfere with tolerances inside the Express Solo.

• If using conduit stub-ups (ie., not using surface conduit entry), conduits must stub-up 13–25 mm (0.5–1 in) above the mounting surface.

Below is a sample depiction of wire entry via conduit stub-ups.

(1) Cabinet front side

(2) Cabinet intake (right) side

(3) 48 V DC, Ethernet, Safety Hub, and door interlock

(4) AC input

(5) Shunt trip

(6) DC BUS (intake side)

(7) EXT B

(8) DC BUS (exhaust side)

(9) EXT D

Stub-up Conduit Specifications

Conduits For	Conduit Quantity x Size (O.D.)
AC input	3 x 103 mm max. or 4 x 78 mm max.
DC BUS: DC BUS (intake side) DC BUS (exhaust side)	1 x 103 mm max. per side or 2 x 78 mm max. per side
External DC output: EXT B EXT D	1 x 103 mm max. per output or 2 x 78 mm max. per output
48 V DC, Ethernet, and Safety Hub (*)	1 x 27 mm to each Power Link 1 inch size conduit is required. The quantity of conduits will depend on the configuration.
Ethernet and door interlock (**)	1 x 27 mm
Optional Features (Soft shutdown switch, shunt trip, hardwire Ethernet)	1 x 21 mm max. per feature

Wire Terminal and Bus Bar Locations

The following identifies the wire terminals and bus bars accessible from the intake side (right side) of Express Solo. (Safety shields are hidden from view.)

Express Foundation and Cables Entry

Ref	Part
(1)	Safety Hub ports
(2)	Ethernet ports
(3)	DC terminal block for 48 V DC, soft shutdown switch, door interlock sensor wires
(4)	Shunt trip terminals
(5)	DC BUS (intake side) bus bars
(6)	EXT B bus bars

The following identifies the wire terminals and bus bars accessible from the exhaust side (left side) of Express Solo. (Safety shields are hidden from view.)

Express Foundation and Cables Entry

Ref	Part
(1)	Ground/PE bar (with wire landing studs)
(2)	EXT D bus bars
(3)	DC BUS (exhaust side) bus bars
(4)	AC input (L1, L2, L3) and neutral bus bars

Wire Specifications

Electrical Characteristics

The following table summarizes circuit current, voltage, conductor rating, and configuration for each circuit to support proper conductor selection.

Electrical Characteristics

Circuit	Maximum Current	Circuit Voltage / Conductor Rating	Number of Poles
AC input	Refer to AC Continuous Input Current table	400 V AC; conductor rating in accordance with applicable local and national codes	3 + PE
DC BUS (power sharing)	750 A	1000 V DC minimum conductor insulation rating	2 + PE
External DC output	Depends on Power Link model and configuration	1000 V DC minimum conductor insulation rating	2 + PE
48 V DC output	32 A	48 V DC; 300 V minimum conductor insulation rating	2
Shunt trip, Safety Hub, and door interlock	-	Same conductor insulation rating as AC input	2 (twisted pair)

Conductor Material and Temperature Rating

The following requirements apply to conductor material and temperature ratings:

• For AC input and external DC output (EXT B, EXT D) and DC BUS conductors, use copper or aluminum conductors rated for 90 °C (194 °F).

• For 48 V DC, shunt trip, Safety Hub, and door interlock conductors, use copper conductors only.

Insulation Requirements

Select conductor insulation types based on these requirements:

• Conductor insulation type must be suitable for the installation environment (e.g., dry, damp, or wet locations).

• For shunt trip, Safety Hub, and door interlock conductors, due to routing proximity to power conductors, use insulation with the same voltage rating as the AC input conductors.

Neutral Configuration

Express Solo is available in two factory configurations: with a Neutral landing or without one. A Neutral connection is not required for standard charging applications. However, some Vehicle‑to‑Grid (V2G) systems rely on phase‑to‑neutral voltage measurements for control functions. When planning a V2G deployment, contact ChargePoint to ensure the correct Express Solo configuration is selected.

Lugs and Terminations

Plan for lugs and terminations using the following requirements:

• Use lugs that are compatible with the selected conductor material and with the nickel-plated landing bus bars provided in Express Solo.

• When using aluminum lugs, ChargePoint recommends applying an appropriate antioxidant compound to aluminum conductors when terminating into tin-, nickel-, or silver-plated lugs, where required by code or specified by the lug manufacturer.

Field Verification

After pulling conductors through conduit, all AC input, external DC output, and DC BUS conductors must undergo insulation resistance testing to verify that insulation has not been damaged during the pull.

For AC input, Express Solo allows a maximum of 18 total current carrying conductors. If utilizing this wiring configuration, install spreader bars at the breaker or transformer to split the outputs across the high number of conductors.