Electrical Design

This section provides electrical design guidelines for Express Solo.

Electrical Supply Requirements

This section provides electrical supply requirements for Express Solo.

Electrical Input

Express Solo requires the following electrical service characteristics:

  • Supply system: 230/400 V AC, 3-phase grounded WYE (Y) configuration

  • Frequency: 50 Hz

  • Maximum input current: 850 A

  • Required conductors: L1, L2, L3, and Protective Earth (PE)

  • Neutral conductor: Not required for standard charging applications

  • 400 V AC 3-phase Delta (D) configuration (including corner-grounded Delta transformer) is not acceptable.

  • Express Solo is available in two factory configurations: with neutral landing or without neutral landing. A Neutral connection is not required for standard charging applications. Certain Vehicle-to-Grid (V2G) applications may require phase-to-neutral voltage measurements for control functions. Contact ChargePoint before planning a V2G deployment to ensure the correct Express Solo configuration is selected.

Branch Circuits and Overcurrent Protection

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

Continuous Input Current

Recommended breaker size

350 kW

542 A

600 A

500 kW

789 A

800 A

525 kW

800 A

900 A

Express Solo has a short circuit current rating of 100 kA.

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

Grounding and Earthing Requirements

Express Solo is categorized as class 1 equipment and therefore its chassis must be connected to a grounded, conductive, and permanent wiring system in accordance with IEC 60364 and/or applicable national standards.

Express Solo provides an isolated DC output. The DC positive and negative conductors must not be bonded to ground or protective earth. Grounding requirements apply to the equipment chassis only.

Provide a PE conductor sized according to local regulations.

Earthing systems

TN-SClosed Terra Neutral Separate, TN-CClosed Terra Neutral Combined-S, TN-CClosed Terra Neutral Combined, and TT type supply networks are supported, subject to local codes. Connect Express Solo only to the following systems:

If connecting Express Solo to a TT network, refer to Residual-current devices (RCDs) for further requirements.

Do not connect Express Solo to IT 400 V AC systems.

Residual-current devices (RCDs)

If an RCDClosed Residual Current Device has to be installed in the supply line per code (as is usual for installation in the TT network), contact ChargePoint for RCDClosed Residual Current Device selection.

Grounding and bonding sequence

When connecting Express Solo to Power Links, charging components must be ground bonded in sequence from Express Solo to Power Link.

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.

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.

Shunt Trip Wiring Diagram

  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

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.

Soft shutdown switch requires a dedicated wire conduit. For more information, refer to Standard Wire Entry Wiring Requirements.

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.

WARNING: The external DC output wires from the Express Solo could still be energized with the switch closed.

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. Using that data, 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.

  • All wiring and conduit is supplied by the contractor unless otherwise indicated.

  • For V2G and energy storage applications, contact ChargePoint for wire and conduit requirements.

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 EVSEClosed 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 (STPClosed 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.

IMPORTANT: Conduit and wire size/quantity are shown for illustrative purposes only. The actual quantity and size of conduits and wires for your specific site may vary and shall depend on site specific requirements.

(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

IMPORTANT: The following table provides the maximum size and quantity of conduits that can be installed on Express Solo configured for standard wire entry. The actual conduit size and quantity must be chosen based on site specific wiring requirements.

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

(*) 48 V DC, Ethernet, and Safety Hub wires travel in the same conduit when connecting Express Solo to a Power Link. Safety Hub wires are required only for certain models of Power Link. Refer to the installation guide of the Power Link model specific to your project to determine if Safety Hub twisted wire connection is required. (**) Ethernet and door interlock sensor wires travel in the same conduit when pairing an Express Solo to another Express Solo.

Wire Terminal and Bus Bar Locations

The Express Solo has four bus bar landings (A, B, C, and D) at the bottom of the cabinet.

  • On the intake side, A and B are for the DC BUS and EXT B connections.

  • On the exhaust side, C and D are for the DC BUS and EXT D connections.

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 A
(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 C
(4)

AC input (L1, L2, L3) and neutral bus bars

AC input, external DC output, and DC BUS conductors must extend a minimum height of 600 mm (24 in) from the finished mounting surface to ensure they reach their landings.

Wire Specifications

The requirements and specifications in this section reflect what is supported by Express Solo. When Express Solo is connected to another ChargePoint product, such as a Power Link charging dispenser or battery, conductor characteristics may be further constrained by the connected product. Refer to the site design guide for each connected product and follow the most stringent requirements.

The following table summarizes the conductor requirements for each circuit.

Conductor Requirements

Circuit / Application

Min. Conductor Voltage Rating

Number of Poles

Insulation

Type

Conductor Material / Min. Temperature Rating

AC Input

0.6/1 kV, or as required by applicable national and local electrical installation codes

3 + PE

 

 

 

 

 

Select type to be suitable for the installation environment (e.g., dry, damp or wet conditions)

Must be copper or aluminum, rated for 90°C (194°F)

 

 

 

 

 

DC BUS

1000 V

 2 + PE

Select type to be suitable for the installation environment (e.g., dry, damp or wet conditions)

Must be copper or aluminum, rated for 90°C (194°F)

External DC Output

1000 V

2 + PE

48 V DC Output

300 V

2

Select type to be suitable for the installation environment (e.g., dry, damp or wet conditions)

 

 

Copper wire only

 

 

Shunt Trip

Same voltage rating as AC input conductors (due to routing proximity to power conductors)

Twisted pair

Safety Hub and door interlock

300 V

Twisted pair

IMPORTANT: Following are wire design specifications for Express Solo, including the maximum quantity and size that the wire terminals can accommodate. All sizing assumes a maximum ambient temperature of 50 °C (122 °F). Where the maximum wire size is listed, the actual wire quantity and size must be chosen based on site-specific wiring requirements and in accordance with the maximum allowed conduit filling rate per local code.

Express Solo Wire Specifications

Wire

 Max. Current

Quantity

Size

AC input

350 kW unit: 542 A

500 kW unit: 789 A

525 kW unit: 800 A

Max. 18 wires

(six per phase)

Max. 150 mm2 (1-core unarmored). Alternates allowed if bend radius ≥ 200 mm (7.9 in) and lug width ≤ 36 mm (1.3 in).

AC protective earth (PE)

 -

Max. 3 wires

(1 per AC conduit)

Refer to local code for size

DC BUS -

intake side

750 A

Max. 8 wires

(four per pole)

Max. 150 mm2 (1-core unarmored). Alternates allowed if bend radius ≥ 200 mm (7.9 in) and lug width ≤ 36 mm (1.3 in).

 

DC BUS -

exhaust side

750 A

Max. 8 wires

(four per pole)

External DC output - EXT B

 250-600 A, depending on Power Link model and configuration

Max. 8 wires

(four per pole)

Max. 150 mm2 (1-core unarmored). Alternates allowed if bend radius ≥ 200 mm (7.9 in) and lug width ≤ 36 mm (1.3 in).

 

External DC output - EXT D

 250-600 A, depending on Power Link model and configuration

Max. 8 wires

(four per pole)

DC grounding

 -

Max. 2 wires per interface

(1 per interface conduit)

Refer to local code for size

48 V DC output

32 A

Max 4 wires per Power Link

(2 wire pairs; each pair has one wire per pole) (*)

16 mm2

Ethernet

 -

Max. 3 cables

1 per Power Link

1 for hardwire Ethernet (if needed)

Outdoor-rated Cat6 STPClosed Shielded Twisted Pair or extended reach cable(**)

Door interlock sensor

 -

2 wires

1.5 mm2

Safety Hub

 -

2 wires per Power Link (***)

2.5 mm2

Soft shutdown switch

 -

2 wires

2.5 mm2

Shunt trip

 6A

2 wires

2.5 mm2

(*) The required number of 48 V DC wire pairs depends on the distance between Express Solo and Power Link. See Wire Run Lengths. (**) The required Ethernet cable type depends upon the cable run length. See Ethernet Requirements. (***) Safety Hub is not required for all models of Power Link. Refer to the installation guide of the Power Link model specific to your project to determine if Safety Hub twisted wire connection is required.

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.

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.

Plan for lugs and terminations using the following information:

  • 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.

Lug Specifications

Wire

Termination

AC input

Lug: Compression lug; short barrel and tongue with single hole sized for M12 (0.5 in) stud

Max. tongue width: 36 mm (1.3 in).

AC PE/ground

Lug: Short barrel and tongue with single hole sized for M6 (0.25 in) stud

DC BUS

Lug: Compression lug; short barrel and tongue with single hole sized for M12 (0.5 in) stud.

Max. tongue width: 36 mm (1.3 in).

External DC outputs

Lug: Compression lug; short barrel and tongue with single hole sized for M12 (0.5 in) stud.

Max. tongue width: 36 mm (1.3 in).

DC grounding

Lug: Short barrel and tongue with single hole sized for M6 (0.25 in) stud.

48 V DC output

Stripped wire end or ferrule

Ethernet

RJ45 connector, shielded

Door interlock sensor

Stripped wire end or ferrule

Safety Hub

Stripped wire end

Soft shutdown switch

Stripped wire end or ferrule

Shunt trip

Stripped wire end or ferrule