ABYC Definition of Ignition Protection

E11.4.15    Ignition protection - the design and construction of a device such that under design operating conditions:

 

a. it will not ignite a flammable hydrocarbon mixture surrounding the device when an ignition source causes an internal explosion, or

 

b. it is incapable of relasing sufficient electrical or thermal energy to ignite a hydrocarbon mixture, or

 

c. the source of ignition is hermetically sealed

 

 

What this means

 If gasoline vapour is present in a space all of the electrical equipment in the space must be ignition protected to avoid causing a fire.  Unless specifically labelled "Ignition Protected" all electical equipment is assumed to be capable of causing small sparks which can start a fire.  Even fuses can cause a fire when they blow unless they are specifically designated as ignition protected fuses.  The standard also applies to spaces with CNG or propane in specified concentrations.  Ignition protected equipment is specially designed to prevent sparks either because the electrical connections are in a hermetically sealed container or because they have been designed to prevent heat transfer to the atmosphere.

 

To comply with the standard gasoline powered boats must have ignition protected equipment in the engine compartment, and the engine compartment must be sealed from any spaces in which non-ignition protected equipment is located.  Any boats with gasoline stored below decks must have only ignition protected equipment in the area where the gasoline is stored.  The storage area must be sealed from any other area where non-ignition protected equipment is located.

 

"Explosion Proof" is not the same as ignition protected, this more severe standard is defined in the National Electrical Code of the NFPA.  Explosion proof equipment is also considered ignition protected.

 

 

Applicable Standards

 

Test standards include SAE J1171, External Ignition Protection of Marine Electrical Devices and

 

UL 1500 , Ignition Protection test for Marine Products, and

 

USCG electrical system requirements in Title 33 CFR 183.410(a)

 

 

Additional information

 

ABYC E.11.5.3  contains additional information on the subject including diagrams showing how compartments are to be isolated.

 

See also the Blue Sea Systems paper on ignition protection.

(This list is a work in progress and does not include every item)

All the Blue Sea battery switches are ignition protected

All the Bussmann 187-Series and 285-Series circuit breakers are ignitions protected

All the ANL Fuses are ignition protected EXCEPT those of 600 Amps and up

No fuses other than ANL or Terminal Fuses are ignition protected by themselves but some qualify when used in a sealed fuse holder like this Safety Fuse Block for Mega fuses, or the Safety Fuse Block for Midi fuses, or the SafetyHub series of products.  Ignition protected fuse blocks for Maxi Fuses, Ignition protected fuse blocks for Class-T fuses, 

The Blue Sea Systems Pacific Series Battery Chargers are ignition protected

More to follow, this is not an exhaustive list and just an introduction to the subject. Its good to note though that ignition protection makes products more expensive and so manufacturers like to point out when something is ignition protected.  So if it doesnt say it is then it probably isnt.  !!