Active Harmonic Filter Cost: What Determines the Price?
Active Harmonic Filter Cost: What Determines the Price?
An active harmonic filter price is not meaningful until the duty and delivery scope are defined. Two quotations can describe “an AHF” but cover different compensating-current ratings, voltage classes, harmonic targets, enclosure forms, current transformers (CTs), commissioning work and warranties. A low equipment-only number may become the higher installed cost once the cabinet, ventilation, protection and site testing are included. For a useful comparison, send every supplier the same measured load profile, point of installation, performance target and scope sheet. Then evaluate the total installed and operating cost, not a single catalog figure.
This guide explains what changes a quotation and how to prepare a request for quotation (RFQ). It does not publish a universal price or promise a specific saving. Pricing depends on the country, currency, quantity, design, project conditions and the supplier’s current offer. Ask for a dated, site-specific quotation before making a purchasing decision.
Start with a measured harmonic duty, not motor nameplate power
The first cost driver is the required compensating current at the selected location. An AHF must be sized for the harmonic orders, phase loading, operating states and any other enabled compensation functions it will actually handle. Motor kW or transformer kVA alone cannot establish that current. A facility with several variable-frequency drives can have a different harmonic spectrum from another facility of similar connected power. The AHF sizing guide for VFD loads explains why representative measurements and operating scenarios matter more than a shortcut based on nameplate totals.
Give bidders measured order-by-order current, fundamental current, voltage, load diversity and the worst credible simultaneous operating state. State where the instrument was connected, the measurement period and whether temporary process conditions were captured. For a rapidly changing load, include event data as well as averages. A supplier may recommend a larger rating, parallel modules or a different configuration if the measured peak duty cannot be met by the initial proposal. That changes price for a legitimate engineering reason. Conversely, buying unused current capacity without a growth case raises cost without proving a better result.
Define the target separately from the capacity. If the requirement concerns distortion at the point of common coupling (PCC), identify that point and its existing background conditions. IEEE 519-2022 addresses harmonic-control objectives at the PCC; it is not an AHF price list, and a filter’s display reading alone does not establish PCC compliance. The acceptance method and site boundary should be in the RFQ so quotes are comparable.
Image: illustrative scope review using the wall-mounted AHF product form. Final dimensions and clearances must come from the selected model’s drawings.
Seven factors that change an AHF quotation
The table is a buyer’s comparison framework, not a claim that any one CNBYG model includes every option. Obtain a line-item bill of materials and identify what is excluded.
| Cost driver | Why the quote changes | What to specify or request |
|---|---|---|
| Compensating-current rating and module count | Higher measured duty, redundancy or future expansion can require more capacity and hardware. | Measured harmonic-current spectrum, peak scenarios, growth allowance and proposed current rating per module. |
| System voltage and electrical architecture | Voltage class, three- or four-wire topology and neutral-current requirement affect the compatible design. | One-line diagram, nominal voltage, frequency, grounding arrangement and neutral-load data. |
| Performance and enabled functions | Harmonic mitigation, reactive-power support or unbalance correction can compete for available current. | Priority of functions, target at each measurement point, test method and response under capacity limit. |
| Enclosure and environment | Wall versus rack/cabinet installation, ingress protection, cooling and ambient conditions alter the complete assembly. | Room conditions, dust/moisture exposure, cabinet drawings, heat rejection and approved clearances. |
| CTs, protection and integration | Sensor quantity, ratio, wiring route, breakers and communication requirements add equipment and labor. | CT location/ratio, available space, protection coordination and monitoring protocol. |
| Engineering, testing and commissioning | Site survey, factory tests, installation support and before/after measurement are often separate line items. | Included drawings, test records, travel, energization support and acceptance criteria. |
| Warranty, spares and service | Coverage, local response, replacement parts and training affect lifecycle cost and bid risk. | Written warranty terms, exclusions, spare-parts list, support location and service options. |
A quotation that does not state these assumptions cannot be fairly ranked against a more complete proposal. It may still be valid as a budgetary indication, but label it as such.
Cabinet and installation costs are easy to overlook
The AHF module is only part of a working installation. A wall unit needs a suitable mounting location, electrical clearances, incoming protection, cable routing and access for service. A rack unit may require a verified cabinet assembly with rails, airflow paths, thermal management and room for CT and power wiring. The AHF cabinet cooling checklist goes deeper into heat and ventilation; those requirements can alter both the initial cabinet price and operating energy use.
Where a supplied electrical assembly is in scope, ask how the design and verification requirements are handled. IEC 61439-1 sets general rules for low-voltage switchgear and controlgear assemblies, while IEC 60529 defines degrees of protection provided by enclosures. Neither standard supplies a universal AHF price or automatically requires one enclosure rating for every site. The relevant requirements depend on the specified assembly, location and jurisdiction.
Installation labor can be substantial where shutdown access is limited, cable distances are long, CT circuits need rework, or the plant requires special permits and witnessed tests. Separate the supplier’s deliverables from the electrical contractor’s. Otherwise a “turnkey” bid and an equipment-only bid can appear deceptively close on a comparison sheet.
Image: illustrative cabinet-space review with a product-referenced rack AHF. It does not show an energized installation or approved final layout.
Compare total cost across the service life
An installed-cost comparison should include equipment, enclosure, CTs, protection, shipping, duties where applicable, installation, commissioning and acceptance testing. A lifecycle comparison adds estimated electrical losses, ventilation or cooling energy, planned maintenance, spares, expected replacement work and the cost of unavailable capacity. Use the supplier’s model-specific loss and maintenance data rather than a generic internet percentage. Document the electricity tariff, operating hours and analysis period used in any calculation.
Do not treat a projected energy saving as guaranteed. Harmonic mitigation may be needed to protect equipment or meet an agreed performance objective even when an energy-payback claim is uncertain. Ask which measured baseline supports any saving estimate and who will verify it after installation. If two suppliers promise different outcomes, compare the test boundary, load state and instrument method before comparing their headline numbers.
For uptime-critical systems, an additional module or service agreement may be valuable, but it is not automatically cheaper. Assign a realistic cost to a process interruption and document the assumptions. A buyer can then distinguish a justified reliability premium from unused features.
A practical RFQ packet for comparable bids
Prepare one technical packet and issue the same revision to every bidder. Include the one-line diagram, voltage and frequency, grounding and neutral arrangement, operating schedules, major nonlinear loads, and measured harmonic data with dates and instrument locations. Mark the intended AHF connection point and the PCC if it differs. Identify any planned VFD or process expansion that could change the duty.
State the desired outcome: the relevant harmonic metric, measurement location, operating cases and acceptance procedure. Specify whether reactive-power or unbalance compensation is required, and ask how the controller prioritizes functions when capacity is limited. The AHF harmonic compensation settings guide explains why priorities must be tested against actual load states. An RFQ that only says “reduce THD” leaves too much ambiguity for a reliable price comparison.
Add physical requirements: indoor or outdoor location, temperature, dust, moisture, available dimensions, mounting form and access restrictions. Include who supplies the CTs, protection, cabinet, cable, drawings, installation labor, commissioning and performance report. Request a line-item base price, optional items, exclusions, lead time, warranty, service response and validity date. If pricing is in different currencies or Incoterms, normalize the commercial basis before ranking proposals.
Finally, ask each supplier to state its sizing calculation and assumptions. Where the proposal differs from the RFQ, require a deviation list. A technically transparent higher quotation can be safer than a lower number that silently excludes the work needed to meet the target.
Questions to ask before accepting the lowest bid
Confirm whether the proposed current rating is a continuous usable rating under the site’s ambient and cabinet conditions. Ask how the unit behaves at its current limit, whether other functions reduce the available harmonic current, and whether parallel units are included or merely “future-ready.” Check whether the quoted enclosure protects against the actual environment, not a hypothetical clean room.
Review the CT arrangement and its cost. Wrong ratio, polarity or location can make an otherwise correctly sized filter underperform. The AHF CT ratio guide details that commissioning risk. Ask who takes responsibility for CT selection, installation and verification. Then compare the acceptance test: does it measure the source current and harmonic result under a representative load, or only show the AHF is powered on?
Read exclusions literally. If a bid excludes commissioning, site travel, interconnecting cable, protection or local service, add a realistic allowance before calling it cheaper. If the proposal relies on a proprietary spare, request availability and lead time. A dated quotation plus an explicit scope is more useful than a generic online “price range.”
Neutral video on filter configuration
The IIT Roorkee lecture below introduces hybrid active filters and shows why filter architecture is a technical choice. It is educational context, not a CNBYG price comparison or a substitute for site-specific sizing. A buyer should not infer that the topology in the lecture is the one proposed for a particular product.
Foire aux questions
What is the typical active harmonic filter price?
There is no dependable universal figure. The rating, voltage, functions, enclosure, location, CTs, installation and service scope differ by project. Use a measured duty and common RFQ packet to obtain dated, comparable quotations.
Does a larger AHF always give better value?
No. Reserve capacity can be justified for measured peak duty, growth or redundancy, but unused rating also increases initial cost. Ask suppliers to show the sizing basis and performance at the intended load states.
Why are two AHF quotes so far apart?
They may include different current ratings, cabinet forms, CTs, protection, commissioning, warranties or commercial terms. Compare line items and exclusions before judging the difference as a product-price difference.
Should I compare AHF cost with passive filters?
Yes, where both are technically viable for the measured system and performance goal. Compare the complete installed design, operating behavior across load changes, maintenance and acceptance method—not equipment price alone. A qualified engineer should assess resonance and system interaction for any passive option.
Request a project-specific proposal
Send the measured load data and scope packet to a qualified supplier. The CNBYG active harmonic filter product page shows the relevant AHF product family; confirm the exact model, rating and available configuration with CNBYG rather than inferring specifications from a photograph. A useful proposal will state the assumed duty, included hardware, exclusions and how performance will be tested. That is the basis for a purchasing decision you can defend later.