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Two-mode Safety and
Battery System Service
Safety Overview
PowerPoint Presentation 1
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Two-mode Safety and
Battery System Service
• Personal Protective Equipment
• Required
• Recommended
• Precautions
• Electrical Safety
• Vehicle Safety
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Personal Protective
Equipment (PPE)
•
Refers to the safety materials and equipment used when working nearby or servicing
high voltage systems
•
Proper guidelines and correct use of PPE should be executed each and every time a
high voltage system is serviced
•
Two types of PPE
• Required
• Recommended
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Required Personal
Protective Equipment
•
Required PPE:
• Safety glasses with side shields
• Class 0 insulation gloves
•
Class 0 insulation gloves are a protective system consisting of:
• Leather outer glove
• Rubber inner glove
•
Rubber inner glove provides insulation against electrical current
•
Protective leather glove shields the rubber insulation from being
altered or destroyed
•
Class 0 insulation gloves create a barrier between electrical current
and user
Danger: Class 0 insulation gloves resist voltage up to 1000 volts.
Class 0 insulation gloves must be worn when servicing high voltage
systems. If they are not used, serious injury or death may occur.
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Required Personal
Protective Equipment
•
Class 0 insulation glove inspection procedure must be performed prior to servicing high
voltage systems:
•
Remove rubber glove from the outer leather protector
•
Inflate the glove and pinch the opening tightly to seal the opening and prevent air
loss
•
Press the glove to increase pressure inside the glove, and inspect for pin holes, air
leaks, wear, tear, or abrasions
•
In addition to inspecting gloves, there is also a date stamp on each glove that must
be certified up to date
•
Each glove must be re – certified every six months, in order to ensure proper glove
protection
•
If any of the criteria mentioned are not met, do NOT use the gloves
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Required Personal
Protective Equipment
•
Safety glasses, which must include side
shields, are also a PPE requirement
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Recommended Personal
Protective Equipment
•
Rubber soled shoes are recommended when working on high voltage
systems
•
These types of shoes are non – conductive, and help isolate the wearer
from the earth ground
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Recommended Personal
Protective Equipment
•
Because electrical shock is almost
always associated with burns, it is
recommended that non – synthetic
clothing be worn when servicing high
voltage systems
•
Any cotton clothing is non – synthetic
and suitable to wear when servicing
these systems
•
Wearing synthetic clothing may result
in burns to skin, since this type of
clothing melts at high temperatures
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Recommended
Precautions
Before Servicing High Voltage Systems:
•
•
•
Remove any jewelry that can conduct
electricity and cause shock, such as:
•
Watches
•
Rings
•
Necklaces
Remove metal objects from pockets that
may fall and create arc flash hazard, such
as:
•
Mechanical pencils
•
Tools
Remove or cover metal on clothing
* Arc flash is produced when current suddenly flows due to loss of isolation between electrodes.
•
Characterized by unexpected dissipation of instantaneous power across conductive path.
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Recommended
Precautions
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Electrical
Safety
There are two factors of
electricity on the body,
voltage and current.
• Voltage - pressure
that causes electron
flow
• Current - flow of
electricity through a
circuit.
(which could include the
human body)
The higher the voltage and
current flow, the more severe
damage to your body if it
becomes part of the circuit.
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Electrical
Safety
•
Current passing through the body can cause electric shock, resulting in potential
injuries such as:
– Surface and internal tissue burns
– Broken bones and muscle damage resulting from falls
• At 16 mA, the muscles clamp on to whatever the person is holding.
– Nervous system effects
• Breathing can stop at 30 mA.
• Ventricular fibrillation can occur at 75 to 100 mA.
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Electrical
Safety
•
Ventricular fibrillation means the
heart is twitching and there is no
blood flow to the body.
•
The heart can be damaged
because it is in the path of most
common pathways:
– Hand to hand
– Hand to foot
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Electrical
Safety
Circuits completed through grounding:
Across the Body:
Across the Hand:
To avoid these conditions:
• Use category III rated DMM and test leads rated to 1,000 volts
when measuring the high voltage bus
• Use PPE
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Electrical
Safety
When you become part of the circuit:
Across the Body:
Across the Hand:
Pretty Obvious
To avoid these conditions:
• Use category III rated DMM and test leads rated to 1,000 volts
when measuring the high voltage bus
• Use PPE
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Vehicle
Safety
High Voltage Interlock Circuit (HVIC)
– When any service cover is
removed, the High Voltage source
is interrupted to prevent access to
energized electrical circuits
– Features:
• Manual Disconnect Lever
• HV DC cable extension cover
• PIM Motor Cable Cover
• Transmission Cable Access
Cover
Danger: The HVIC system should NOT be relied on to disconnect the high voltage sources to the vehicle, since
this interlock circuit will have no effect if the high voltage contactors fail in the closed position. If the contacts
were stuck, a cover could therefore be removed, and the system would still be active. Relying on the HVIC
system to disable high voltage may cause serious injury or death.
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Vehicle
Safety
“Live-Dead-Live”
Live - Check your DMM against a
known voltage source
(vehicle’s 12 volt battery)
Dead - Check circuits for no
voltage present
Live - Check DMM against same
known voltage source to
assure checks were valid
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Vehicle
Safety
When Servicing a Two-mode Hybrid Vehicle Remember To:
•
Wear PPE
•
Verify vehicle is off and NOT in Auto Stop
•
Attach keys and manual disconnect lever
•
Store in a safe, secure place
•
Never leave a high voltage system exposed
•
Use a Category III DMM and test leads rated up to 1000 volts
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Any Questions?
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