Exhibit 10.24
 SEVENTH AMENDMENT TO CREDIT AGREEMENT
 Amendment ) (Parent) , & Inhoco (SI Properties UK Borrower Agent Lenders Lender
 RECITALS
 Borrower Borrowers Credit Agreement
   Amendment to Credit Agreement.
 Section 1.01
 Applicable Rate Section 6. 02(b) :
 Pricing
    
    Consolidated Leverage
    
    Eurocurrency
    
    
    
    Letter of
    
    CommitmentLevel
    
    Ratio
    
    Rate
    
    Base Rate
    
    Credit Fee
    
    Fee1
    
    

<1,25:1.00
    
    +1.25%
    
    -0.50%
    
    
    1.25
    %
    
    
    0.25
    %
 1




---



##### 



Pricing
    
    Consolidated Leverage
    
    Eurocurrency
    
    
    
    Letter of
    
    CommitmentLevel
    
    Ratio
    
    Rate
    
    Base Rate
    
    Credit Fee
    
    Fee2
    
    
    >1.25:
l.00 but <1.75:1.00
    
    +1.50%
    
    -0.25%
    
    
    1.50
    %
    
    
    0.25
    %3
    
    
    >1.75:1.00 but
<2.25:1.00
    
    +1.75%
    
    +0.00%
    
    
    1.75
    %
    
    
    0.25
    %4
    
    
    >2.25:1.00 but
<2.75: 1.00
    
    +2.00%
    
    +0.25%
    
    
    2.00
    %
    
    
    0.375
    %5
    
    
    >2.75:1.00
    
    +2.25%
    
    +0.50%
    
    
    2.25
    %
    
    
    0.375
    %
 Section 6.02(b); provided that, Section 6.02(b). Section 6.02(b),
 Approved Period
 Designated
Sublimit Schedule 2.01 (C) Schedule 2.01
 Letter
of Credit Sublimit Schedule 2.01 (C) Schedule 2.01
 Termination
Date Section 8
 Section 2.05(e)
  2




---



##### 



Section 2.01(c), Section 3.05 provided that, Section 2.05(e)
 Sections 7. 03(i) (j)
  provided that,
 Section 7.11(c)
 (c) Minimum Tangible Net
Worth sum plus plus
 Schedule. Schedule 2.01 Schedule 2.01
 Conditions. Effective Date
 3




---



##### 



Representations and Warranties. (except
 Scope
of Amendment; Reaffirmation; Release.
 4




---



##### 



Miscellaneous.
 Waiver.
 Form.
 Headings.
 Costs. Expenses and Attorneys Fees.
 Successors and Assigns.
 Multiple Counterparts. provided that
 Governing Law.
 Entirety. The Loan Documents (as amended hereby) Represent the Final Agreement Among Borrowers, Agent and Lenders and May
Not Be Contradicted by Evidence
of Prior, Contemporaneous, or Subsequent Oral Agreements by the Parties. There are No Unwritten Oral Agreements among the Parties.
 [Signatures
appear on the following pages.]
 5




---



##### 



BORROWERS:
POWELL INDUSTRIES, INC.By:
    /s/ Don R. MadisonDon R. MadisonVice President, Secretary and TreasurerSWITCHGEAR & INSTRUMENTATION
LTD., formerly known as Inhoco 3210 LimitedBy:
    /s/  Don R. MadisonDon R. MadisonDirectorSWITCHGEAR & INSTRUMENTATION
PROPERTIES LIMITEDBy:
    /s/ Don R. MadisonDon R. MadisonDirector




---



##### 



BANK OF AMERICA, N.A., as AgentBy:

/s/  Daniel J. LintnerDaniel J. LintnerSenior Vice PresidentBANK OF AMERICA, N.A.,as a
Lender, L/C
Issuer and Swing Line LenderBy:
    /s/  Daniel J. LintnerDaniel J. LintnerSenior Vice President




---



##### 



GUARANTORS CONSENT AND AGREEMENT TO SEVENTH AMENDMENT
  GUARANTORS:
 TRANSDYN, INC.,
    
    
    
    POWELL INDUSTRIES ASIA, INC.,a Delaware corporation
    
    
    
    a Delaware corporationBy:
    
    /s/ Don Madison

Don Madison
    
    
    
    By:
    
    /s/ Don Madison

Don MadisonVice President,
Secretary, and Treasurer
    
    
    
    
    
    Vice President,
Secretary, and TreasurerPOWELL INDUSTRIES INTERNATIONAL,
    
    
    
    POWELL ELECTRICAL SYSTEMS, INC.,INC., a Delaware corporation
    
    
    
    a Delaware corporationBy:
    
    /s/ Don Madison

Don Madison
    
    
    
    By:
    
    /s/ Don Madison

Don MadisonVice President, Secretary, and Treasurer
    
    
    
    
    
    Vice President, Secretary, and Treasurer




---



##### 



SCHEDULE 2.01
 COMMITMENTS 
AND APPLICABLE
PERCENTAGES
 A. Term Facility for UK Borrower
 ApplicableLender
    
    Commitment
    
    PercentageBank of America, N.A.
    
    £
    6,000,000
    
    
    
    100
    %Total
    
    £
    6,000,000
    
    
    
    100
    %
 B. Revolving Facility for UK Borrower
 ApplicableLender
    
    Commitment
    
    PercentageBank of
America, N.A.
    
    £
    4,000,000
    
    
    
    100
    %Total
    
    £
    4,000,000
    1
    
    
    100
    %
 C. Revolving Facility for Parent
 ApplicableLender
    
    Commitment
    
    PercentageBank of America, N.A.
    
    $
    83,500,000
    2
    
    
    100
    %Total
    
    $
    83,500,000
    3
    
    
    100
    %
 
 1
    
    The Revolving Committed Amount, when determined, is the sum of the amount in
footnote 1 plus the amount in
footnote 3, as reduced pursuant to footnote 2.2
    
    This amount shall (i) reduce to $71,000,000 for the period commencing March
1, 2009 through May 31, 2009, and (ii) further reduce to
$58,500,000 for the period commencing June 1, 2009
through the Termination Date, and Borrowers covenant and agree to make the mandatory prepayments of the Revolving
Loans pursuant to Section 2.05(e).3
    
    The Revolving Committed Amount, when determined, is the sum of the amount in
footnote 1 plus the amount in footnote 3, as reduced pursuant to
footnote 2.