When is Hot to Hot? Electrical thermographic survey article for use on a superyacht, yet also applicable for everyday use.

2. ONBOARD | SUMMER 2023 | 53
ONBOARD | SUMMER 2023 | 53
ADVERTORIAL
WHEN IS
HOT TOO
HOT?
ADVERTORIAL
WHEN IS
HOT TOO
HOT?
E
lectricity is one utility that we all
take for granted, and immediately
miss whenever an outage or blackout
occurs. Dead in the water is a cliché that
is thankfully underused, much thanks to the
pool of talent of the engineering crew and
shore based support within our industry,
servicing equipment to exacting standards.
As set forth in the various flag administration
Safety Codes, Class certificates and
insurance prerequisites that are all designed
to bring about compliance and safe maritime
operation.
Compliance measures are applicable to
the size of the yacht, with safety and
maintenance at their forefront. One modern
maintenance technique mentioned in yacht
inspection and maritime advisory notifications
is the endorsement for thermal imaging
cameras.
To capture a moment in time albeit a heat
image (thermogram) is certainly worth more
than a thousand words to the yacht owner.
A thermal camera can, when used properly,
identify electrically generated hotspots in
a quick and timely manner, rapidly steering
crew to perform corrective maintenance,
that if left unnoticed, create excessive
heat likely to cause an outage or worse
an electrical fire.
When overheating occurs within an electrical
system, it can be a sign of loose, over-
tightened, corroded connections, undersized
conductors, or another failure mode due
to high resistance.
Your checklist for periodic yacht based
thermal inspections:
• Electrical switchboards, including the
emergency board
• Distribution boards
• Auxiliary equipment, motors, bearings,
and starter panels
• Transformers
• Cable raceways
• UPS and Li-ion battery systems
• Shore power connections
Most electrical faults tend to occur at the
weakest points in an energised system.
When a component is failing, a run-away
effect can occur, causing the temperature
to dramatically rise. It is Ohm’s law (P=I2R)
that describes this relationship, between
current, electrical resistance, and the power
or heat energy generated.
Abnormal heating associated with high
resistance or excessive current flow is
the main cause of many problems in yacht
electrical systems. Yacht electrical repairs
should be prioritised by safety first, i.e.,
equipment conditions that pose a safety
risk followed by criticality of the equipment
and the extent of the temperature rise.
So when is hot too hot!? NETA (InterNational
Electrical Testing Association) guidelines
dictate immediate action when the difference
in temperature between similar electrical
componentsundersimilarloadsexceeds15°C
(27 °F) or when the difference in temperature
between an electrical component and the
ambient air temperatures exceeds 40°C
(72 °F). Tests are best performed at 40%
load to be effective.
Safety is also paramount whenever an
electrical inspection is performed. The
removal of secondary dead-front guards
is necessary to achieve a direct line of
sight, yet no contact is necessary as the
thermal camera passively detects the radiant
heat from the components. Component
temperatures exceeding thresholds are a
cause for concern, directing the chief to
engage secondary systems before significant
thermaldamageoccurs.Moreover,prompting
part replacement orders and preventative
maintenance scheduling.
Damage caused by overheating is usually
irreversible; the only way forward is to
replace the component part - a challenging
task if no spares are carried onboard.
Disruption is likely, with failure rates
exacerbated by the age of the yacht plus
inspection and maintenance histories.
Typically, third party thermographic surveys
are performed on an annual basis by an
independent Class registered inspection
company - providing the impartiality insurers
and yacht management companies seek,
and of course, complemented with periodic
thermal scans by the yacht engineering
crew trained in the technique.
Remember, energised electrical components
can become hot enough to melt, causing
outages and fire, so plan your independent
thermal survey before your next voyage - it
could be the best thing
you do today.
For more details visit
www.geothermltd.co.uk
Geo Therm’s Tony Dale
discusses the use of thermal
imaging to mitigate yacht
outages and fire
E
lectricity is one utility that we all
take for granted, and immediately
miss whenever an outage or blackout
occurs. Dead in the water is a cliché that
is thankfully underused, much thanks to the
pool of talent of the engineering crew and
shore based support within our industry,
servicing equipment to exacting standards.
As set forth in the various flag administration
Safety Codes, Class certificates and
insurance prerequisites that are all designed
to bring about compliance and safe maritime
operation.
Compliance measures are applicable to
the size of the yacht, with safety and
maintenance at their forefront. One modern
maintenance technique mentioned in yacht
inspection and maritime advisory notifications
is the endorsement for thermal imaging
cameras.
To capture a moment in time albeit a heat
image (thermogram) is certainly worth more
than a thousand words to the yacht owner.
A thermal camera can, when used properly,
identify electrically generated hotspots in
a quick and timely manner, rapidly steering
crew to perform corrective maintenance,
that if left unnoticed, create excessive
heat likely to cause an outage or worse
an electrical fire.
When overheating occurs within an electrical
system, it can be a sign of loose, over-
tightened, corroded connections, undersized
conductors, or another failure mode due
to high resistance.
Your checklist for periodic yacht based
thermal inspections:
• Electrical switchboards, including the
emergency board
• Distribution boards
• Auxiliary equipment, motors, bearings,
and starter panels
• Transformers
• Cable raceways
• UPS and Li-ion battery systems
• Shore power connections
Most electrical faults tend to occur at the
weakest points in an energised system.
When a component is failing, a run-away
effect can occur, causing the temperature
to dramatically rise. It is Ohm’s law (P=I2R)
that describes this relationship, between
current, electrical resistance, and the power
or heat energy generated.
Abnormal heating associated with high
resistance or excessive current flow is
the main cause of many problems in yacht
electrical systems. Yacht electrical repairs
should be prioritised by safety first, i.e.,
equipment conditions that pose a safety
risk followed by criticality of the equipment
and the extent of the temperature rise.
So when is hot too hot!? NETA (InterNational
Electrical Testing Association) guidelines
dictate immediate action when the difference
in temperature between similar electrical
componentsundersimilarloadsexceeds15°C
(27 °F) or when the difference in temperature
between an electrical component and the
ambient air temperatures exceeds 40°C
(72 °F). Tests are best performed at 40%
load to be effective.
Safety is also paramount whenever an
electrical inspection is performed. The
removal of secondary dead-front guards
is necessary to achieve a direct line of
sight, yet no contact is necessary as the
thermal camera passively detects the radiant
heat from the components. Component
temperatures exceeding thresholds are a
cause for concern, directing the chief to
engage secondary systems before significant
thermaldamageoccurs.Moreover,prompting
part replacement orders and preventative
maintenance scheduling.
Damage caused by overheating is usually
irreversible; the only way forward is to
replace the component part - a challenging
task if no spares are carried onboard.
Disruption is likely, with failure rates
exacerbated by the age of the yacht plus
inspection and maintenance histories.
Typically, third party thermographic surveys
are performed on an annual basis by an
independent Class registered inspection
company - providing the impartiality insurers
and yacht management companies seek,
and of course, complemented with periodic
thermal scans by the yacht engineering
crew trained in the technique.
Remember, energised electrical components
can become hot enough to melt, causing
outages and fire, so plan your independent
thermal survey before your next voyage - it
could be the best thing
you do today.
For more details visit
www.geothermltd.co.uk
Geo Therm’s Tony Dale
discusses the use of thermal
imaging to mitigate yacht
outages and fire