class 1 in Aircraft hangar

T mcc

Member
Location
tennessee
Occupation
Electrical Superintendent
I'm currently doing multiple aircraft hangars that have everything below 18" as class 1 area. Each hangar has a bifold door that has a receiver and transmitter just like most common garage door systems. They each are fed with SO cord and terminate above in Controller that isn't in class 1 zone. Since the operating voltage is 24V does cords have to be run in raceway? The transmitter and receiver are both sealed units. They are both shown mounted to floor.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I'm currently doing multiple aircraft hangars that have everything below 18" as class 1 area. Each hangar has a bifold door that has a receiver and transmitter just like most common garage door systems. They each are fed with SO cord and terminate above in Controller that isn't in class 1 zone. Since the operating voltage is 24V does cords have to be run in raceway? The transmitter and receiver are both sealed units. They are both shown mounted to floor.
You might be able to make an argument that the SO cord is OK in a class 1, division 2 area. However, I think the sensor needs to be listed for use in the classified area and there needs to be a seal. If they are factory sealed that may be acceptable.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
The voltage does not change the wiring method requirements found in 501.10. For a Class I, Division 2 area you need to use one of the wiring methods found in 501.10(B).
As Bob said the sensor will need to be suitable for use in a Class I, Division 2 area.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
If you are talking about the obstruction sensing mechanism (light beam) for door safety, that can be mounted above 18" and still work properly for life safety when closing doors.
 

T mcc

Member
Location
tennessee
Occupation
Electrical Superintendent
If you are talking about the obstruction sensing mechanism (light beam) for door safety, that can be mounted above 18" and still work properly for life safety when closing doors.
I thought of that but they are bifold doors and have cables so above 18" is not an option. Cables come down to 6" above floor.
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Mount them in little boxes outside the doors? :)
Is the 18" classified zone still present outside the doors when they are open? Rbalex?
Typically, where a boundary is not created by a physical barrier such as a wall or partition, a small hazard radius will be included beyond various openings like doors and windows. Depending on the hazard radius of the source, the small hazard radius would be 3 to 5 feet.
 
Top