Phase Converter Warranties by Maker (2026): What Lifetime Covers and What Voids It

Phase converter warranties run from one year to "lifetime." At American Rotary and Phoenix, the lifetime term covers only the control panel. At NAPCco, the lifetime term covers panel labor only. NAPCco covers panel parts for 10 years. After year 10, you pay for replacement parts, and NAPCco still covers the labor.

The idler motor is the motor that works with the control panel to make 3 phase power from your single phase supply. American Rotary and Phoenix buy their idler motors from motor makers, and the motor maker's warranty covers the idler. That term is shorter than the lifetime panel term: two years from Baldor on American Rotary units, and three years from North American Electric Motors or Techtop on Phoenix units.

American Rotary, NAPCco and Ronk say in writing that their warranties stay with the original buyer. A used converter may come with no warranty at all. The warranty documents of American Rotary, Phoenix and NAPCco also say a licensed electrician must do the install. The makers' warranties list what they don't cover, such as an install that fails local code, the wrong supply voltage, and repairs the maker didn't approve.

Built for Production read the warranty terms of eight phase converter makers on October 15, 2026, to put them side by side. Six of them publish a full warranty document: American Rotary, Phoenix, NAPCco, Phase Technologies, Kay and Ronk. Phase-A-Matic and ARCO print only the length, such as "1-YEAR WARRANTY," on a brochure or product page, with no terms beyond that.

We check every document in this guide again each month and update this page when a term changes. Dated copies of each maker's document are linked near the end of this guide. The warranty papers that ship with your unit are the ones that apply. If a term here decides your purchase, ask the seller for that maker's current warranty document in writing before you order.

How long is each maker's phase converter warranty?

Rotary converter warranties run from ARCO's one year to lifetime panel coverage at American Rotary and Phoenix. Three parts can carry separate terms: the control panel, the idler motor and the rotor. The rotor is the spinning part inside the idler motor.

• American Rotary's warranty page lists its lifetime coverage for "AR, AD, ADX, AI and AMP Smart Series Only." If you're looking at its AUL line, ask for that manual's warranty section before you buy.
• Kay's three manuals (2014, 2021 and 2026) say 61 months from shipment. Its phasemaster.us warranty page says 62 months. The five years from installation is the same in all four.
• Phase-A-Matic's term appears only as one bullet in its rotary brochure. The brochure prints no start date, no parts or labor split and no idler term. We found no warranty page on its site.
• ARCO prints "1-YEAR WARRANTY" in the feature list on each of the seven series pages we read. We found no document that says what the year covers.

Static converter terms run 12 months to two years. Phase-A-Matic's static brochures say "GUARANTEED 12 MONTHS AGAINST MANUFACTURING DEFECTS," NAPCco's static warranty sets parts at twelve months, and Kay's Type MP page lists a "Two year warranty."

What does a "lifetime" phase converter warranty cover?

In converter warranties, "lifetime" covers the control panel at American Rotary and Phoenix, panel labor at NAPCco, the rotor at Phoenix, and bearings at Kay. No maker's warranty document puts the whole idler motor under a lifetime term.

• American Rotary: control panels "are warranted against defects in material and workmanship for a lifetime." DIY panels are excluded, and the AD-STK panel gets 1 year. American Rotary's manuals at revisions R2.6 to R2.9 don't mention the rotor, so there's no separate rotor promise in writing. If rotor coverage matters to you, ask American Rotary before you buy.
• Phoenix Phase Converters: control panels are "backed by a lifetime warranty, safeguarding against defects in materials and craftsmanship." The idler motor as a whole has the motor maker's three years. The rotor inside it "comes with a lifetime warranty for the original owner."
• NAPCco: the document is titled "Rotary Phase Converter Limited Lifetime Warranty." The lifetime part is labor. NAPCco "will maintain the control panel and perform repairs caused by normal use at no charge for the useful life of the panel." Panel parts are covered 10 years and capacitors 1 year.
• Kay Industries: the term is five years, with one lifetime clause. Kay "will replace all defective bearings regardless of cause for the life of the converter."

The FTC's Businessperson's Guide to Federal Warranty Law says "lifetime" "can be used in at least three ways": the life of the product, as long as the original buyer owns it, or as long as the original buyer lives. The guide tells sellers to say which "life" they mean. NAPCco's lifetime labor runs for the useful life of the panel. Kay's bearing promise runs for the life of the converter. American Rotary and Phoenix don't say whose life their panel coverage runs for.

Where Phoenix's own pages disagree

If you buy Phoenix, ask which document governs your unit, and get the answer in writing. Its pages say different things:

• Idler motor. Its Industrial Grade Rotary Phase Converter product page says, "Every converter ships with a lifetime warranty on the motor and panel." Its Warranty Policy page, its August 2025 Technical and Installation Manual and its NL / PL Installation and Operation Manual give the idler motor three years.
• Wear items. Phoenix's homepage FAQ says, "Wear items (contactors, fuses) are covered for 1 year." Its August 2025 manual says, "Normal wear items are excluded."
• Shipping. The Warranty Policy page says you pay to ship a control panel to Phoenix, and Phoenix pays to send it back. The homepage FAQ says, "If a covered part fails, we ship a replacement next-day air at our cost."
• Full terms. The homepage FAQ says, "Full warranty terms are on the back of every invoice." Read the back of your invoice before you file a claim.

Who covers the idler motor on a rotary phase converter?

At American Rotary, Phoenix and NAPCco, the company that built the idler motor covers it under its own warranty.

• American Rotary: Baldor covers the idler. Repairs go to a Baldor Authorized Service Center. "American Rotary will not accept Baldor idler returns or repairs sent to American Rotary."
• Phoenix Phase Converters: North American Electric Motors or Techtop covers the idler. Repairs go to that motor maker's Authorized Service Center. Phoenix will not accept idler returns sent to it.
• NAPCco: the idler is "Covered separately by the manufacturer and subject to their terms and conditions." Its Pro-Line PL-10 spec sheet adds a footnote: "Idler Motor warranty covered by ABB/Baldor." NAPCco's warranty gives no idler term length.
• Kay Industries: the document names no separate idler term. Its one term covers "all products of our manufacture." If another company made the idler on your unit, that wording may leave the idler out, so ask Kay before you buy.
• Ronk: the document names no separate idler term. Its term covers "RONK MANUFACTURED Goods," and anything Ronk sells from another maker carries that maker's warranty only. Ask Ronk who made the idler on your unit.
• Phase-A-Matic: its R-5 product page says to call Phase-A-Matic for warranty repair stations in your area.

How do you file a phase converter warranty claim?

Some makers set a deadline for reporting a defect. Ronk's is 30 days from when you find it. After you report it, get the maker's approval before you ship a part or start a repair. Phase Technologies, which makes the Phase Perfect digital phase converter, gives that approval as a return authorization number called an RMA. Ronk does the same. Ronk's warranty calls it an RGA, a Return Goods Authorization.

American Rotary's manual calls the idler the "generator." When you read its warranty section, "generator" means the idler motor.

Who pays shipping on a phase converter warranty claim?

At American Rotary, Phoenix and NAPCco, you pay to ship a control panel in, and the maker pays to ship it back on a covered repair. Phase Technologies' manual and its web page (as read October 15, 2026) disagree on who pays the return trip. Kay and Ronk don't promise to pay shipping in either direction.

Kay's document says defective parts are "renewed or replaced at our option F.O.B. factory without charge." Ronk's warranty says Ronk will repair or replace defective goods "FOB Seller's Nokomis, IL factory." F.O.B. (free on board) is a shipping term that names the maker's factory as the hand-off point for the shipment, and neither document says who pays the freight to or from it. Kay adds that it isn't liable for "transportation, labor or expense." Ask either maker who pays the freight before you ship anything.

Phase Technologies' V4.7 manual says, "Return transportation is provided by Phase Technologies." Its Warranty, Shipping & Returns page, as read October 15, 2026, says, "Transportation of RMA products is the responsibility of the customer." Ask Phase Technologies which one applies before you ship.

Damage you find when the truck arrives goes through a freight claim, which is separate from the warranty. Our freight delivery checklist covers what to do before you sign.

Does a phase converter warranty transfer if you buy used?

A second owner gets no coverage at American Rotary, NAPCco or Ronk. Phase Technologies wants the original sales order for a claim, and Phoenix's lifetime rotor coverage is for the original owner only. In the makers' words:

• American Rotary: "Warranty is non-transferable and will remain with original purchaser/end user."
• NAPCco: "Warranty is valid for the original purchaser only and is non-transferable."
• Ronk: "The Limited Warranty applies only to the original user of the Goods."
• Phase Technologies: "The original Sales Order must be presented to initiate a return or to obtain 'in-warranty' service." A second owner may not have that sales order. Coverage runs "from the date of purchase by the original purchaser."
• Phoenix Phase Converters: the rotor's lifetime coverage is "for the original owner."

Kay, Phase-A-Matic and ARCO say nothing about transfer.

The term can also run out on a unit that sat unsold or uninstalled. Kay's term ends 61 months after the unit left the factory, even if nobody installed it. Ronk's 36 months start the day the unit ships, and its document says the period "shall not be extended" for a unit that sat unused. Price a used converter as if it has no warranty, because it may not.

What voids a phase converter warranty?

All six makers with a full warranty document say their warranty doesn't cover improper installation: American Rotary, Phoenix, NAPCco, Phase Technologies, Kay and Ronk.

NAPCco's warranty also says the customer is responsible for making sure the install meets all codes and "passes any required inspections."

We don't play electrician. A licensed electrician installs your converter to the maker's manual, the NEC and local code.

How long are digital phase converter and VFD warranties?

Digital phase converters carry one year as standard at Phase Technologies (Phase Perfect), NAPCco (TritonPro Maxx) and Ronk (Electro-Phase, 12 months). Standard terms on VFDs (variable frequency drives) run from 12 months to 3 years, depending on the maker. If you're still deciding between types, our rotary vs digital vs VFD guide covers the trade-offs.

Digital phase converters

Phase Perfect's first year is what Phase Technologies calls its Reliable Power Guarantee. It covers "defects, power surges, lightning, and most accidental damage." Repairs for accidental damage carry a fixed deductible. Phase Technologies offers to extend the Reliable Power Guarantee to up to 5 years on eligible systems, at purchase or during the first year. Its sales department quotes the price.

VFDs with single phase input

• Invertek's clock starts at manufacture. A drive that sat on a shelf has used part of its term before you buy it. Warranty Plus+ "must be purchased when placing your product order."
• WEG voids coverage on drives from unauthorized sellers. Its policy says, "Purchases of WEG products from unauthorized dealers or distributors void warranty coverage." Before you order a WEG drive, ask the seller whether it is an authorized WEG distributor.
• WEG wants notice within 60 days of the failure.
• WEG doesn't pay freight. "WEG is not responsible for any expenses incurred in installation, removal from service, transportation (freight), or consequential expenses."

Will a phase converter void your machine's warranty?

Your machine's maker decides whether converter power affects the machine's warranty. Before you buy a converter, ask the machine's maker in writing whether it covers the machine on converter power, and which converter type it accepts.

Copies of each maker's warranty document

We saved a copy of each document this guide quotes on October 15, 2026. Each copy opens with a cover page that names the document, the date or revision the maker printed on it, and where we got it. These are the terms as they read that day. Makers change their terms, so before you buy, ask the maker for its current version and compare it with the copy.

ARCO prints its term only on its product pages, so there's no document to copy.

What to check before you buy a phase converter

Run this list on any converter or drive before you order.

• The document and its date. Get the warranty for your exact line, with its revision or date. Product page headlines and FAQ lines can differ from the warranty document.
• The term for each part. Control panel, idler motor, rotor, capacitors and wear items can each have a different term.
• The idler claims path. Whose motor it is, which service center handles it, and whether the converter maker must OK the repair in writing first.
• Freight both ways. Who pays to ship the part in, and who pays to send it back.
• When the clock starts. Purchase (NAPCco, Phase Technologies, TECO-Westinghouse), shipment (Ronk, Kay's 61 months), installation (Kay's five years, WEG) or manufacture (Invertek).
• Who can claim. Original buyer only at American Rotary, NAPCco and Ronk. Phase Technologies wants the original sales order to start a claim, so keep yours.
• The install requirement. A licensed electrician, and an install that meets local code.
• The claim steps and deadlines. Who issues the return authorization, what paperwork the maker wants, and how many days you have to report a defect.
• Your machine's warranty. Ask the machine's maker in writing.

If you're down to two or three makers and want to go through the warranty document for the line you're considering, call (855) 923-2610 or email contact@builtforproduction.com. We'll go through it with you: the term for each part, who pays freight, who can claim, and what voids it.