<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2006-11-09</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000835910</issuerCik>
        <issuerName>AMERICAN POWER CONVERSION CORP</issuerName>
        <issuerTradingSymbol>APCC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000923734</rptOwnerCik>
            <rptOwnerName>SCHNEIDER ELECTRIC SA</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>43-45 BD FRANKLIN ROOSEVELT</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>RUE IL-MALMAISON</rptOwnerCity>
            <rptOwnerState>I0</rptOwnerState>
            <rptOwnerZipCode>92500</rptOwnerZipCode>
            <rptOwnerStateDescription>FRANCE</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21383663</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On October 28, 2006, Schneider Electric, SA (&quot;Schneider Electric&quot;), Trianon Inc. (&quot;Merger Sub&quot;), and American Power Conversion Corporation (the &quot;Issuer&quot;) entered into an Agreement and Plan of Merger (the &quot;Merger Agreement&quot;), pursuant to which the Issuer will become an indirect wholly owned subsidiary of Schneider Electric.  In connection with the execution of the Merger Agreement, on October 28, 2006, Schneider Electric entered into a Voting Agreement (the &quot;Voting Agreement&quot;) with Rodger B. Dowdell, Jr. and Neil E. Rasmussen, (the &quot;Shareholders&quot;), with respect to shares of common stock of the Issuer (?Common Stock?) held by the Shareholders representing an aggregate number of shares equal to 9.56% of the shares of Common Stock outstanding on the date of the Voting Agreement.</footnote>
        <footnote id="F2">On November 9, 2006, Rodger B. Dowdell, Jr. exercised stock options to acquire 1,255,300 shares of Common Stock  and the shares of Common Stock received by Mr. Dowdell in connection with the exercise of the stock options became subject to the Voting Agreement.  Furthermore, according to the Schedule 14A filed by the Issuer with the Securities and Exchange Commission on November 13, 2006, as of November 9, 2006, the Shareholders held 21,383,663 shares of Common Stock, which included (i) the shares received by Mr. Dowdell in connection with his November 9, 2006 exercise of stock options and (ii) 466,000 shares of Common Stock that are issuable pursuant to the exercise of stock options beneficially owned, by Neil E. Rasmussen, which will become subject to the Voting Agreement when and if the underlying stock options are exercised.</footnote>
        <footnote id="F3">Pursuant to the Voting Agreement, Schneider Electric may be deemed to have beneficial ownership pursuant to Section 13(d) of the Securities Exchange Act of 1934, as amended (the &quot;Exchange Act&quot;) of 21,383,663 shares of Common Stock beneficially owned by the Shareholders.  Neither the filing of this statement nor any of its contents shall be deemed to constitute an admission by Schneider Electric that it is the beneficial owner of any of the common stock referred to herein for purposes of Section 16 of the Exchange Act or for any other purpose, and such beneficial ownership is expressly disclaimed.  Schneider Electric has no &quot;pecuniary interest&quot; in the common stock referred to herein.   For additional information regarding the Voting Agreement and the Merger Agreement, see the Schedule 13D and the Schedule 13D/A filed by Schneider Electric with the Securities and Exchange Commission on November 6, 2006 and November 15, 2006, respectively.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Juan Pedro Salazar, Senior Vice President and General Counsel</signatureName>
        <signatureDate>2006-11-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
