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Product Innovation ReportHow Corrosion on the Negative Battery Terminal Destroys ECIMs
Test-proven Field Retrofit Solution Offered
27 May 2014
Hood Tech Proprietary 5/27/2014
Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
Applicability
• Mark 4 Commercial Launcher• HTL4.1 (STUAS Launcher)
Hood Tech Proprietary 5/23/2014
Negative Battery Lead Corrosion Destroys ECIMs; Field Retrofit Solution
Offered
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Problem Report• NSW (T3) reports melted blue wires inside the ECIM and
uncommanded system shut-down following Compressor start attempt.
• Replacing ECIM resulted in melted ECIM wires on the new ECIM.
• Upgrading compressor start circuit at compressor did not help; a third ECIM was destroyed with the same symptoms as the first two.
• The site is located near salt water. Battery terminal corrosion and evidence of arcing reported from the site, which confirms the root cause analysis.
Hood Tech Proprietary 5/27/2014
Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
Field Failure (photo 1 of 5)
4Hood Tech Proprietary 5/27/2014
Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
Field Failure (photo 2 of 5)
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Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
Field Failure (photo 3 of 5)
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Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
Field Failure (photo 4 of 5)
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Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
Field Failure (photo 5 of 5)
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Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
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Root cause:•Corrosion build-up prevents compressor start current from returning directly to negative battery terminal. Instead, it passes first through ECIM, returning via trailer chassis and generator negative battery leads.
•Overloaded blue wire shorts with leads carrying +12VDC or +24VDC inside ECIM, which causes internal voltage droop and system shut-down.
Hood Tech Proprietary 5/27/2014
Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
Hood Tech Re-enactmentCompressor Start Commanded with Wiring Fault (simulated corrosion) as shown in Previous Slide.
>100 amps observed through clamp-on ammeter.
10Hood Tech Proprietary 5/27/2014
Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
Compare Damagewith Fielded Launcher. Image taken after 5-seconds of “Compressor-Start” Commanded
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+24V (orange)Shorted to-12V (blue), causing systemto shut down
Hood Tech Proprietary 5/27/2014
Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
Compare Damage
12Hood Tech Proprietary 5/27/2014
Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
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Test-proven RemedyArrange negative battery leads as shown and add a 10A fuse to protect
ECIM from large start currents demanded by compressor starter.
Note: HTL4.2 ECIMHas introduced this fuse protection inside the ECIM
Hood Tech Proprietary 5/27/2014
Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution
Offered
Retrofit Kit
Hood Tech Proprietary 5/27/2014
Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
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As Installed
Hood Tech Proprietary 5/27/2014
Negative Battery Terminal Corrosion Destroys ECIMs; Field Retrofit Solution Offered
Hood Tech Proprietary 15
Stainless steel clamping bolt grounds negative battery terminal to trailer chassis
Isolated and fuse-protected post terminates ECIM –battery lead
ECIM -battery lead(Not included)
