SVG Capacity Expansion with Parallel Modules

SVG capacity expansion with parallel modules can add reactive-current capability without replacing the original installation, but only when the equipment, bus, protection, cooling, CT measurement and controller support coordinated operation. Empty cabinet space is not proof that another module can be added. Start with the measured growth duty, the existing model and firmware, the available short-circuit and thermal margins, and the supplier’s approved parallel architecture. Then test current sharing and the loss of one module before calling the expansion complete.

Establish the growth case

Define why capacity is needed. It may be a new VFD bank, a production expansion, a revised power-factor target, a redundancy requirement or a measured peak above the original design. Capture the current and future kW, kvar, voltage, phase/wire system, harmonic spectrum, operating states and ambient condition. Do not size the new module only from a percentage of connected motor power.

Compare the original commissioning baseline with current measurements. A changed CT boundary, process sequence or capacitor bank can look like capacity growth. The SVG power-factor troubleshooting guide helps separate a sizing issue from an input or coordination issue.

O Página do produto CNBYG SVG is the product context; the original model’s parallel capability, current rating, controller and installation drawings control the expansion.

Reveja o SVG installation requirements for low-voltage switchboards before changing cabinet space, cable entry or cooling provisions.

Expansion review table

Require each answer in writing. If the new module changes an assumption, update the complete design rather than attaching a generic extension note.

Parallel current sharing

Parallel units can share reactive current through a master/follower, synchronized controller, droop or another approved method. The name of the method is less important than the evidence that each module receives the right command and remains within its limits. Confirm phase order, CT boundary, communication path, address or ID, firmware and settings.

During commissioning, record each module’s output, temperature, alarm state and total source current under the same load. Check low, medium and peak duty. Look for one unit consistently carrying more current, a delayed start, oscillation or an alarm that appears only after another module joins. Correct the cause before declaring a balanced system.

Image: illustrative rack expansion review using the product-referenced SVG module.

Cabinet, bus and protection changes

Adding a module changes current, heat, cable routing, short-circuit contribution and protective coordination. Confirm busbar or terminal capacity, conductor size, termination, branch protection, isolation, fault withstand and enclosure assembly responsibility. A spare rack position may not have a spare breaker, bus section or cooling path.

Review whether the added unit needs a new CT, a shared CT input or an updated controller. Do not place a second CT on a conductor without an approved measurement design. Update the one-line, wiring schedule, protection settings and labels. For low-voltage assemblies, IEC 61439-1 provides general assembly rules; the project and local requirements determine the application.

Cooling and environment

Add the new module’s model-specific losses to the cabinet and room calculation. Map intake and exhaust for every unit, including the failure of a fan or a dirty-filter condition where the design requires it. Prevent the new module from discharging warm air into the original module. Confirm door, roof, side and rear clearances remain available.

If the expansion changes enclosure or ingress protection, IEC 60529 defines the IP classification language. An IP change can change the thermal path. Do not solve a heat problem by blocking a required opening or bypassing a filter.

Image: illustrative cabinet airflow review; the final layout must use the approved model drawings.

CT and control migration

Decide whether the existing CTs remain at the correct boundary and whether their burden and wiring support the expanded controller. Confirm each module’s measurement input, phase sequence and communication. Export the original settings before making changes. Record the new module ID, firmware, control priority and sharing parameters.

Do not commission the expansion by changing several variables at once. First confirm the original module alone, then the new module at low duty, then combined operation. Keep a safe fallback state and document how the extra module is isolated. A plant should know how to run temporarily at reduced capacity after a module fault.

Test plan and acceptance

Acceptance should include the original load cases plus the growth case. Measure total source current, reactive power, power factor, voltage, SVG output per module, ambient and alarms. Test module start/stop, communications loss, current limit, temperature response, remote stop and loss of one module under an approved procedure. If the design claims redundancy, define the remaining capacity and target after one unit is unavailable.

For harmonic or unbalance functions sharing the converter, record those outputs and priorities as well. The Lista de verificação para a implementação do SVG provides a general evidence structure. For PCC harmonic objectives, use the project’s agreed measurement method and IEEE 519-2022 as applicable guidance.

Perform a staged energization rather than connecting all new equipment at once. Confirm the original module with the baseline settings, then verify the new module’s identity and low-duty response, then enable coordinated sharing. At each stage record source current, module output, voltage, temperature, alarms and communication status. If one stage fails, the retained records show whether the issue follows the new module, the cabinet position or the common controller.

Define a rollback state before the outage. Operators should know how to isolate the added module and return to the approved original configuration without defeating protection. Keep the original settings export, breaker state and as-left drawings available. After acceptance, update the asset register and maintenance plan so the extra module, fan, filter and control parts are inspected with the rest of the system.

Pay attention to uneven aging. Modules installed in different cabinet positions can experience different dust, airflow and temperature even when their nameplates match. Trend each module separately and keep its serial, firmware and service history. If one module is replaced later, recheck sharing and do not assume the new firmware or hardware revision is transparent to the existing controller.

The growth calculation should also state what it does not cover. A new module may add reactive capacity without solving a changed harmonic spectrum, feeder voltage problem or resonance concern. If the expansion follows a new VFD or capacitor bank, repeat the relevant power-quality study and update the acceptance cases. This keeps the investment tied to the actual system need.

Procurement and service checklist

Request compatibility, dimensions, mounting, heat data, current-sharing method, firmware, communication, CT requirements, protection, bus and cable scope, commissioning, warranty, spares and exclusions. Ask whether the original module requires an update and whether a future module must be the same hardware revision. Record lead time for fans, control boards and complete modules.

Provide the electrical contractor with a revision-controlled package. Include a shutdown plan, isolation points, lifting method, settings backup, test instruments and acceptance sign-off. The expansion is a system change, not merely a new box.

Before releasing the outage, have the owner approve the revised single-line diagram, protection settings and test boundaries. Keep a clear distinction between the capacity that the modules can produce and the capacity that the feeder, transformer and cooling system can safely carry. This review prevents a successful bench test from becoming an overstressed plant installation.

Include the responsible engineer and the approved rollback decision in the outage record. A clear owner for each check keeps the expansion controlled when several contractors share the same shutdown window.

Vídeo neutro: controle de filtro ativo no fundo

The IIT Roorkee lecture below provides neutral background on shunt active-filter operation. It does not describe the specific parallel architecture of a CNBYG SVG.

Perguntas frequentes

Can I add any SVG module to a spare cabinet slot?

No. Verify model family, voltage, firmware, rail support, protection, bus, cooling, control and current-sharing compatibility.

Does a second module double usable capacity?

Not automatically. Combined capacity depends on voltage, ambient, sharing, enabled functions, protection and the system’s limiting component.

Should the existing CTs be replaced during expansion?

Only after the approved measurement design confirms ratio, burden, location, polarity and controller input requirements. Do not add or move CTs casually.

How do I prove redundancy?

Test the loss of one module under an approved procedure and record remaining current, thermal state, alarms and the achieved target at the defined measurement point.

Expansion outcome

Parallel SVG expansion is successful when the growth case, compatibility, current sharing, protection, cooling, measurement and single-module fallback are all documented and tested. Treat the additional module as a controlled system modification, not a simple capacity plug-in.