Power Control Systems (PCS): Operating Modes and Settings Configuration

Applicable products and scope

This article uses the S6-EH1P high-voltage US user manual, version 5.6, April 2026, whose listed models are S6-EH1P3.8K-H-US, S6-EH1P5K-H-US, S6-EH1P7.6K-H-US, S6-EH1P9.9K-H-US, S6-EH1P10K-H-US, and S6-EH1P11.4K-H-US (manual, cover). Its PCS discussion and commissioning instructions are the model-specific basis for this guide; the low-voltage S6-EH2P UL 3141 article expressly applies to a different product family (manual, pp. 26–27 and 61–68, S6-EH2P certification article).

The certification document can be downloaded by scrolling to the bottom of this article and then clicking on the file.

Common acronyms and terms

The distinction between general site import/export and battery-specific PCS terminology follows the manual’s separate export-control, PCS-mode, and scheduling sections (manual, pp. 16, 27, 65 and 68).

What PCS controls

A Power Control System electronically controls current or power to maintain defined limits at a specified measurement point; PCS functions can address power exchange with the utility, loading of controlled conductors, or other specifically evaluated functions (UL PCS guidance). A PCS certification is therefore not a blanket declaration that every power-control feature is supported: the specific functionality is defined by the product’s listing, instructions, and ratings (UL PCS guidance).

For this article, distinguish three different control objectives:

The four ESS mode names describe allowed exchange directions, whereas Self Use and TOU describe energy priorities and dispatch timing (manual, pp. 18, 27 and 65). This is why an operating outcome can require several ordinary settings rather than a single menu option bearing the mode’s name.

What the inverter supports

CHINT metering requirement

For an installation relying on this inverter’s PCS certification, use the approved CHINT DTSU666 metering arrangement and current sensors; the PCS hardware illustration identifies this combination (manual, p. 26). The older “Acrel 1P Meter” instruction in Quick Settings is not the applicable PCS metering instruction and must not be used to substitute an Acrel assembly for the qualified CHINT arrangement.

Certification and panel-design limits

The manual’s general PCS text discusses busbar loading, but its reproduced certificate explicitly identifies ESS Import Only and Export Only rather than a complete set of separately named busbar, feeder, and branch-circuit overload-control functions (manual, pp. 26 and 92). Consequently, this article does not authorize a panel-sizing exception, removal of required overcurrent protection, or use of a user-adjustable export limit as proof of overload-protection compliance.

For a design that relies on PCS instead of a conventional panel interconnection calculation, obtain the applicable model-specific certification and approved installation design for review by the responsible designer and authority having jurisdiction. Do not transfer the S6-EH2P family’s UL 3141 claims to this S6-EH1P family; the S6-EH2P article expressly limits its scope to that low-voltage series (S6-EH2P certification article).

Understanding the four PCS modes

The four names describe permitted battery/grid exchange, not whether the entire home can import electricity and not whether the battery must continuously charge or discharge (manual, p. 27). Use this permission table together with the configuration sections below.

Export Only does not mean the home cannot import grid power. It prohibits grid charging of the battery; the manual separately explains that utility power can supply a load deficit (manual, pp. 16 and 27).

The settings that implement the power-flow logic

The configuration recipes below are an engineering synthesis of these documented controls, not a laboratory record showing that each recipe was the configuration used for certification. The zero-export recipes deliberately restrict both PV and battery export; they must not be represented as a selective “PV may export, battery may not” control (manual, pp. 16, 27, 65 and 68).

Settings matrix

Use the following baseline to separate permission, dispatch, and the utility-export ceiling; it combines the documented controls rather than inventing a new PCS selector (manual, pp. 18, 27, 64–65 and 68). The detailed procedures explain when a schedule is optional and why the two zero-export configurations are more restrictive than the battery-only definitions.

The ON/OFF and zero-limit combinations above are derived from the documented functions of Allow Grid Charging, TOU, and Grid Power Setting (manual, pp. 65 and 68). A positive export limit must come from the approved site design; this guide intentionally does not prescribe one number for every installation.

Settings not to confuse with an ESS exchange restriction

Before changing settings

Accessing the controls

For local commissioning, the manual shows SolisCloud → Service → Local Operation → Connect with Bluetooth, followed by the inverter Settings screen; export controls are under Grid Power Setting (manual, pp. 62 and 68). The desktop route is plant → Device → inverter → Inverter Control, with Work Mode and Grid Feed In Power Limit sections; Solis notes that exact labels and access vary by model, firmware, and account permissions (SolisCloud desktop control guide).

Use the controls by their documented function, not by assuming that a similarly worded Input Limit or Output Limit label is a direct synonym for one of the four PCS modes. If an additional limit-mode selection is present and its effect is unclear, record it and request model/firmware-specific support rather than changing it speculatively.

Unrestricted battery/grid exchange

The objective is to permit both grid charging and battery export, subject to the site’s interconnection limit and the battery’s operating limits (manual, p. 27). “Unrestricted” is an ESS exchange description, not permission to exceed the site’s approved export level.

For an unscheduled baseline, explicitly save Self Use ON, Allow Grid Charging ON, TOU OFF, Feed in Power Limit Switch ON, and the approved positive export ceiling, then read the settings back (manual, pp. 18, 64–65 and 68). If a schedule is required, enter the customer-approved start/end times and battery-approved nonzero charge/discharge currents rather than copying arbitrary example values; the manual specifies time windows and DC current limits, not a universal schedule (manual, p. 65).

Do not confuse permission with dispatch: default Self Use prioritizes local consumption, and enabling grid charging does not force continuous charging (manual, pp. 18 and 65). A scheduled discharge and a positive export allowance are the logical combination to test when intentional battery export is required; validate the result on the installed firmware before relying on it for a tariff or program.

Import Only using a conservative zero-export configuration

Import Only permits grid charging but prohibits battery export; setting a whole-site export target of zero provides a more restrictive implementation because it also limits PV export (manual, pp. 16 and 27). Use this recipe when preventing all utility export is acceptable.

Save and read back the full combination, not just the numeric zero: Self Use ON, Allow Grid Charging ON, TOU OFF for the baseline, Feed in Power Limit Switch ON, and Feed in Power Limit Value 0 W (manual, pp. 18, 64–65 and 68). A stored limit value of zero with its switch OFF is not an active zero-export instruction (manual, p. 68).

If PV export must remain permitted while battery export is prohibited, do not use this zero-export recipe as though it were source-selective. Default Self Use provides load-following battery operation in the manual’s logic diagram, but the reviewed documentation does not establish that this alone is the certified selective battery-export restriction under every schedule and operating condition (manual, pp. 18, 65 and 92).

Export Only

The required logic is no grid-to-battery charging while allowing battery export when otherwise commanded; the home can still import grid electricity to serve its loads (manual, pp. 16 and 27). This is a battery charging-source restriction, not a whole-site import prohibition.

Save and read back Self Use ON, Allow Grid Charging OFF, TOU OFF for the baseline, Feed in Power Limit Switch ON, and the approved positive export ceiling (manual, pp. 18, 27, 64–65 and 68). Do not configure a grid-charge window as part of this operating outcome; if TOU is used for intentional discharge, verify both the absence of utility-to-battery charging and the commanded discharge behavior.

Battery-protection caution: The manual recommends Allow Grid Charging ON to prevent deep discharge when PV is insufficient, creating an important operating tradeoff for Export Only (manual, p. 65). Review the connected battery’s requirements and low-SOC behavior with Solis before deployment; never defeat BMS protections or lower protective SOC thresholds to force this operating outcome.

No Exchange using a conservative zero-export configuration

No Exchange combines PV-only battery charging with battery discharge to loads, without battery export to the grid (manual, p. 27). The following configuration also limits PV export, making it stricter than a battery-only no-exchange requirement.

Save and read back Self Use ON, Allow Grid Charging OFF, TOU OFF, Feed in Power Limit Switch ON, and Feed in Power Limit Value 0 W (manual, pp. 18, 27, 64–65 and 68). Keep battery discharge available to serve loads; No Exchange does not mean that the battery may never discharge (manual, p. 27).

This configuration does not electrically isolate the home from the utility, and it does not prevent the utility from supplying a load deficit (manual, pp. 16, 18 and 27). Do not select Off-Grid mode as a substitute on a grid-connected installation; the manual reserves that mode for an electrically off-grid system (manual, p. 19).

Zero-export operation without a battery

The S6-EH1P can operate with PV and no battery, and the manual explicitly permits export-power control in that configuration (manual, p. 16). With no battery, the four ESS descriptions do not create a battery charge/discharge path; utility-export control is still necessary to limit surplus PV.

PV-only backup during a grid outage has separate limits: the published Solis bulletin identifies HMI v.1308 and DSP v.0603 for that feature and explains that backup output shuts down when loads exceed available PV (PV-only backup bulletin). Do not infer nighttime backup, battery-backed stability, or guaranteed support for heavy starting loads from a PCS or zero-export setting (PV-only backup bulletin).

Export limiting, strict zero injection, and fail-safe behavior

A 0 W export limit is a control target, not an instantaneous physical barrier: the manual expressly warns of small export overshoot after sudden load changes and suggests external backflow-trip protection for strict zero-injection applications (manual, p. 16). Review the utility’s actual requirement before representing a zero-export configuration as sufficient.

The Solis S6 controls guide describes Fail Safe as stopping generation if communication with the external meter is lost (S6 controls guide). Where export restriction is required, have the installer confirm the applicable Fail Safe setting and test its behavior using a Solis-approved procedure; do not substitute “No Meter” or disable a protection to conceal a metering fault.

Do not prescribe a universal export-calibration offset. Treat calibration as a site-measurement adjustment, not a substitute for correct CT polarity, meter wiring, communication, or the export-limit switch.

Parallel systems and measurement boundaries

The manual allows common working modes and other settings to be synchronized through the master and treats the master’s grid/load data as parallel-system data (manual, p. 68). For a site export restriction, validate the measured total at the utility connection rather than assuming that a reading from one slave proves the whole installation is compliant.

Whole-site zero export and “PV may supply only the backup panel” are different requirements: CTs at the utility service connection measure site exchange, including loads outside the backup panel (Solis metering guidance). A setting that limits power crossing that service boundary does not, by itself, demonstrate zero reverse flow through each inverter’s Grid terminals; review the single-line diagram before promising backup-only routing.

Phase-unbalance guidance needs model- and configuration-specific attention: the manual recommends enabling split-phase unbalance for heavy 120 V loads, while the S6-EH1P support article instructs that Unbalanced Output be OFF for multiple inverters (manual, p. 68, parallel-system note in metering guidance). Do not apply the single-inverter recommendation to a parallel installation without checking the applicable Solis guidance.

Commissioning and verification checklist

Use this checklist to validate the intended operating outcome; these are proposed commissioning checks, not a claim that a field test or laboratory evaluation has already been completed.

Never intentionally deep-discharge a battery to test an operating mode, and never disconnect live CT circuits or energized wiring as an improvised fail-safe test. Arrange any abnormal-condition testing with qualified service personnel using an approved procedure.

Frequently asked questions (FAQ)

Does “Feed in” mean drawing power from the grid?

No: the export-setting instructions use “feed in” for power sold or delivered back to the utility (manual, p. 68). Battery charging from the utility is separately controlled by Allow Grid Charging (manual, p. 65).

Is Self Use the same as Import Only?

No: Self Use establishes energy priority and can still export surplus PV when export is permitted, whereas Import Only describes a restriction on battery export (manual, pp. 18 and 27). The conservative Import Only recipe in this article adds an explicit zero-export limit instead of relying on the work-mode name alone.

Does turning the Feed in Power Limit Switch OFF prevent export?

No: OFF disables that export-limiting function, and the manual states that the system can then export according to its work mode (manual, p. 68). For a zero-export target, the switch is ON and the value is zero (manual, pp. 16 and 68).

Is Peak Shaving the same as PCS Export Only?

No: Peak Shaving uses battery discharge to reduce grid demand above a configured threshold, while Export Only restricts the source used to charge the battery (manual, pp. 18, 27 and 65). Do not treat a peak-shaving threshold as independent evidence of a certified service-entrance or busbar protection function.

Why do the mode names not match every settings screen?

The manual defines operating outcomes separately from its commissioning controls, and Solis notes that interface labels can vary with model and firmware (manual, pp. 27 and 64–68, SolisCloud desktop guide). Use the documented combination of grid-charge permission, export limit, work mode, and schedule; obtain support for any additional Input Limit/Output Limit field rather than assuming a name-based equivalence.