Installation Note: IN0057 - Rev 06

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This installation note will demonstrate how to install and configure SP PRO units in a Powerchain system, either as a single phase, three phase or split phase system with up to three worker units per phase (four SP PRO inverters per phase  one manager, with three worker units).

All diagrams in this installation note are given for reference only. Please ensure all wiring complies with relevant safety standards.


This document needs to be read in conjunction with the SP PRO Instruction Manual and SP LINK instruction manual (both found in the SP LINK Help menu).


All SP PRO inverters in a Powerchain system must:

  • Have the same model number.
  • Have the same firmware.
  • Have a common battery bank.
  • Be reset to factory defaults.
  • Be a SP PRO series 2i or SP PRO series II with Advanced Comm Card Rev 5 and above.


  • System Manager  Must be connected to L1  all configuration, control and interaction is made via this SP PRO.

  • Phase Manager  Main SP PRO on L2, L3 and/or Split (180°).

  • Worker  any other SP PRO within system on any phase.

  • ACC – SP Pro Advanced Comms Card (blue or black).
Summary of steps
The following list is a summary of the steps required to complete the installation. Once the installation is completed, use the list below as a check list:


Installation steps and main points


Install the SP PROs according to the SP PRO Instruction Manual. 

·    Group together manager and workers for a particular phase (see Diagram 1).


Install the AC wiring (see Diagram 1).         

·    AC sub board to be central to SP PROs to minimise wiring length.

·    Keep AC wiring together for all inverters on the same phase.

·    Where possible, run common neutral for all inverters on the same phase.


Install DC Wiring and Configure the Batteries (see diagram 1).

·    DC wiring as short as practicable between SP PRO and DC switchboard.

·    Minimal separation of DC cables, to reduce loop impedance.

·     All DC wiring running together for inverters on the same phase.

·    Maintain equidistance for parallel strings.


Connect the SP PRO Powerchain SYNC connections and terminators.


Update Firmware then restore factory defaults.


Create the configuration for the SP PRO Powerchain system, using the Site Configuration Wizard in SP LINK.


Connect to the SP PRO System Manager via SP LINK, assign the SP PROs in the Powerchain system and save the configuration.


Test the system function.

The SP PROs must be installed as per the installation instructions in the SP PRO Instruction Manual.

It is a good idea to place an inverter assignment label on each SP PRO. This will help to identify each inverter in the Powerchain system during system commissioning and testing.

Install the SP PRO inverters so that the Managers and Workers for a particular phase are physically grouped together. For example in a three phase system with 3 SP PROs per phase install the SP PROs along the wall in the following order; L1 manager, L1 worker 1, L1 worker 2, L2 manager, L2 worker, 1L2 worker 2, L3 manager, L3 worker 1, L3 worker 2 (See Diagram 1).

Circuit Breakers and Isolators
Circuit breakers and isolators shown in diagrams may be either individual or ganged to suit individual installation requirements, either option is acceptable.

AC Wiring
All Neutral connections from inverters must be connected together at the same common point as required. Keep the distance as short as possible between the neutral connections of all of the inverters on the same phase.

The preference is to run one neutral wire per phase, connected at the inverters. Please ensure that the current rating of a common neutral is suitable based on the number of inverters connected. For example, connecting one neutral to 3 off SPMC SP PROs, current rating is 3 x 63A = 189A.

The neutral conductor connecting to the loads must be maintained such that operation of any external SP PRO isolators cannot sever the link between Neutral and Earth.

All of the AC wiring linking the Load L and N circuits between any particular phase manager and its workers complies with the following:

  • Where possible run a single (common) neutral for all SP PRO inverters on the same phase.
  • The L and N cables either run in the same conduit or a twin cable is used. It is important that the cable pairs run in parallel and do not separate.
  • The AC cabling must run together for all the inverters on the same phase.
  • Minimise the AC cable length between an SP PRO and the sub board. It is recommended to have the AC sub board central to the SP PRO inverters to minimise AC cable length.
  • The maximum allowable cable run is 10 metres from any SP PRO to the sub board where there is a single neutral for each phase (point 1).

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Diagram 1: Suggested physical layout of a powerchain system


Figure 1 shows the SP PRO Single Phase Powerchain AC wiring schematic with two workers and an external CT & AC source contactor.

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Figure 1: Single Phase AC wiring schematic with external contactor/CT and two workers
AC Source Power > 15 kW for SPMC or 30 kW for SPLC models

Figure 2 shows the Single Phase Powerchain AC wiring where no external contactor and CT is installed. This configuration can be used when the AC source capacity is no more than 15kW per phase for the SPMC models, or 30kW per phase for the SPLC models.
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Figure 2: Single Phase AC Wiring Schematic with 2 Workers
AC Source Power < 15 kW for SPMC or 30 kW for SPLC models

Figure 3 (following page) shows a Three Phase Powerchain system with two workers per phase. An external three phase AC source contactor is required with external CTs for each phase. 

NOTE:  A three phase Powerchain system with one or more workers per phase MUST have external CTs and an external AC Source contactor fitted.

NOTE:  Three phase circuits which have loads that cannot tolerate a phase failure must be protected by a Phase Failure Relay (not supplied).

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Figure 3: Three Phase AC wiring schematic, external contactor, two workers per phase

Main DC Wiring
The SP PRO Powerchain main DC wiring diagram is illustrated in Figure 4.

Battery protection must be a minimum of 630A per group. After the DC battery protection, the cables can be split into one circuit per SP PRO, each supplied by minimum 70mm2 V90HT cables.  Each circuit is protected by a 250A HRC fuse or DC circuit breaker.

Make sure the DC cables are as short as possible with the +ve and -ve cables running together and Keep DC wiring together for all inverters on the same phase (See Diagram 1).

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Figure 4: Main DC wiring schematic showing nine SP PROs.

Pre-charge and Midpoint Wiring

The SP PRO Powerchain DC pre-charge and midpoint wiring layout is shown in Figure 5.

The pre-charge wiring is wired as a bus arrangement and connected to the battery via a common connection for all SP PROs.  This will allow all SP PROs to be pre-charged together.

The Midpoint wiring need only be connected to the System Manager (L1). The System Manager carries out the battery sense and midpoint readings for the system.

The pre-charge and midpoint wiring must be protected by suitable fuses or a three pole circuit breaker rated at least 2A DC per SP PRO. For the system below (Fig. 5) the pre-charge circuit breaker rating is 18A or more.

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Figure 5: DC pre-charge and midpoint schematic showing nine SP PROs

SP PRO SYNC Interconnection

Every SP PRO in a Powerchain system must be interconnected via its SYNC interface. Connect every SP PRO together via the SYNC-1 or SYNC-2 connection, using the supplied cat5 cables.

The SYNC-1 and SYNC-2 connection points are identical, so either may be used for each connection.

Each SP PRO can be connected together in any sequence, with the most logical sequence being connections between adjacent SP PROs. Ensure that all SP PROs in the Powerchain system are linked into one single SYNC chain.

NOTE: Termination connectors MUST be fitted to the two unused SYNC connectors.

SYNC interconnection of the SP PROs

Firmware Update

Download the latest SP LINK from the Selectronic web site. This will contain the latest SP PRO firmware and the latest Communications Card firmware.

Apply DC power to all the SP PROs in the Powerchain system and wait until they start. The main battery breakers must be ON, not just the pre-charge breakers.

Connect the SP LINK PC to the USB port on the SP PRO that will be assigned as the System Manager (the Manager on L1 phase).

Select Firmware Update from the Easy Start Guide and update all of the SP PROs in the Powerchain system to latest version of firmware. All SP PROs in the Powerchain system will be updated via the System Manager.

For more information on firmware update see  TN0034 - SP PRO Firmware Update Procedure.


Each SP PRO must now be restored factory defaults before setting up Powerchain.  This process clears out the current configuration in the SP PRO inverters so they are ready to accept a new Powerchain configuration.

Restore Factory Defaults

To restore factory defaults:

  1. Apply battery power to the SP PRO and make sure all units are in idle mode.
  2. Press and hold the Generator and Alarm buttons (B).
  3. Whilst still holding these buttons, when the SP PRO beeps do a short press on the On button (C).
  4. All Green front panel LEDs will come on. Let go of the Generator and Alarm buttons.
  5. The SP PRO will now restart and go through the start-up sequence.
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SP PRO Configuration

The Site Configuration Wizard is used to create the configuration for the Powerchain system. All communications and system configuration are carried out by connecting to the System Manager (L1).

Once the system is configured, communications to other SP PROs in the Powerchain system is via the System Manager. The data communications ports on the other SP PROs are disabled.

1.    Make sure the USB lead is connected between the System Manager and PC.

2.    Make sure the DC power is present at all of the SP PROs. 

Wait until the front panel LEDs are stable.

3.    Start Selectronic SP LINK.

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4.    Select Site Configuration Wizard and step though the wizard to setup the system to suite the Powerchain system application.

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Hint: For information on how to use the Site Configuration Wizard, right click on the page in SP LINK and a help guide will appear.

5.    When all settings have been configured in the Site Configuration Wizard, from the menu bar,
select File > Site Information > Save. 

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6.    SP LINK will automatically detect when the System Manager SP PRO is ON and the USB cable is connected.  Click “Connect” to connect to the SP PRO. 
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7.    Go to the Powerchain Inverter Assignments tab.  Drag and drop the serial numbers of the Unassigned Inverters box into L2 or L3 Managers or L1, L2 and L3 Workers as appropriate.
NOTE: To identify an SP PRO, double click on a serial number and the battery LEDs on the associated SP PRO will flash RED for 3 seconds.

8.    Once all SP PROs are assigned, click > Save Assignments. The default settings passcode is 74.

9.    At the Configuration Settings tab, click the “Configure SP PRO” button.

SP PRO Powerchain Configuration is now complete

Operation of the SP PRO

Once the SP PROs are installed and configured correctly, the system is controlled by the System Manager (the first SP PRO on L1). All other SP PROs will follow the operational mode of the System Manager automatically.


1.    Turn on the Battery Sense / Pre-charge isolator (See Fig 3). Wait until the SP PROs turn on.
2.    Turn on the Battery Isolator.

      Image Placeholder    All buttons and battery LEDs are disabled on the Phase Managers and the Workers.

After the SP PRO has powered up and the front panel LEDs are stable:
1.    Connect to the System Manager via SP LINK.
2.    In SP LINK navigate to Data View > Powerchain. Verify that all the real time readings from each of the phases is correct.

3.    SP LINK can also provide individual information for each of the SP PROs in the Powerchain. 
Select > L1 or L2 or L3 in SP LINK, then Manager or Worker to display the SP PRO’s distinct information.
4.    Select the Data View > Now and check that there are no faults displayed in the Attention Required box.


  • Turn off the Battery Isolator
  • Turn off the Battery Sense / Pre-charge isolator

Additional Information

Visit the Selectronic: Knowledge Base or contact Selectronic via Customer Portal