|
Explosion
Proof Door Operators

IMPORTANT
READ BELOW FIRST
Certain Horton automatic door operators might
be used in Nema Class I, Class II or Class III areas, but special considerations must be
made. The chart below should provide a quick guideline. Please consult
a qualified electrical engineer and/or consultant, prior to specifying a door
operator system in hazardous areas. Failure to consult a qualified
electrical engineer could result in death, injury or property loss. Eastern Door Service, Inc. is providing this
information, as a convenient guideline and it is not guaranteed to be
accurate. Eastern Door Service,
Inc. and its employees are
not qualified electrical engineers or consultants.
IMPORTANT
READ ABOVE FIRST
Quick Reference This Page
NEMA
Classification Notes and Considerations
Models
Notes:
- You may not need to use explosion proof
operators or special equipment if it is completely installed in a corridor or room located
opposite a hazardous area (safe side of door opening). The corridor must be a safe
area and have a greater atmospheric pressure than the hazardous area. Make sure
sliding door hold-open beams are installed on the safe side of the door opening.
- Switches located inside a hazardous area
must be intrinsically safe for Class I areas or sealed for Class II areas.
Intrinsically safe wiring must be ran in a separate conduit. Do not make parallel
switch connections within a hazardous area. All parallel electrical connections must
be made within the safe area or within a purged enclosure.
- You might be permitted to use
electro-mechanical door operators within a Class II area, provided the motor is sealed and
not ventilated. Switches must be dust tight or intrinsically safe. Horton
Automatics uses a non-ventilated motor, which Eastern Door vulcanizes to ensure a dust
tight condition. This is not a NEMA 4 or 12 motor, but is usually accepted by the
local governing authority and your consulting electrical engineer.
- Powered switching devices such as motion
sensors and presence detectors might be acceptable in Class II Division II areas, provided
the devices are rendered dust tight. The governing authority must approve the use of
any such devices.
- Use explosion proof pneumatic or explosion
proof electro-pneumatic operators in all Class I areas.
NEMA
CLASSIFICATION |
OPERATOR REQUIREMENTS |
Class I
Flammable vapors or gases might be present in the room's atmosphere.
Division 1
The condition exists continuously or periodically.
Division 2
The condition exists in the advent of an accident or abnormal condition.
Group A
Acetylene may be present.
Group B
Hydrogen may be present.
Group C
Ethyl-ether, ethlsoe or cyclo-propane may be present.
Group D
Gasoline, lacquer, benzene, butane, hexane, naphtha, propane, alcohol, acetone, benzyl, or
natural gas may be present. |
Pneumatic Explosion Proof
Operator:
Door operator must be all pneumatic or electro-pneumatic with electronic controls
and valves mounted in safe area within 50 feet of the door operator location.
Electronic controls and valves might also be mounted within a purged enclosure box if no
safe area is within 50 feet of the door. (Bebco Industries Type Z enclosure for
division 2 and Type Y enclosure for division 1)Switching
and Actuation:
Intrinsically safe non-powered contacts (dry contact switching) must be used.
Powered switching devices such as motion sensors or infra-red photo beams may not
be used. All dry contact switches are wired to an extremely low voltage low amperage
remote mounted relay module, which are installed in a safe area or purged enclosure.
All switching is done through this module. One module is required for each
switching function; i.e. one for actuation control(s) and one for safety
control(s).
A module is not required for each switch, but all switches must have a separate
pair of wires pulled to each switch location. Never parallel wire or daisy chain
wires within a hazardous area. |
Class II
Combustible dust might be present in the room's atmosphere.Division 1
The condition exists continuously or periodically.
Division 2
The condition exists in the advent of an accident or abnormal condition.
Group E
Metal dust from aluminum, magnesium, or their alloys, as well as other hazardous metals
may be present.
Group F
Carbon black (lamp black), coal or coke dust may be present.
Group G
Flour or other grain dust may be present. |
Door Operator:
Pneumatic or explosion proof door operators are not required, but will meet
requirements for Class II areas. Electromechanical door operators must have a NEMA 4
or NEMA 12. In most conditions a sealed and non-ventilated motor is acceptable, but
should be approved by local code officials. Operator limit switches must be sealed
or intrinsically safe. Rubber boot or seal must be used where the output shaft
protrudes through the operator cover. The control box and electronics must be
installed in a NEMA 4 or NEMA 12 enclosure box. Sloped operator covers should be
used to prevent dust build-up.Door operators
can open a door, when mounted on either side of a wall. The simplest means to
automate doors safely in a Class II area, would be to mount them on the safe side of the
door opening, if such a condition exists. Actuation switches in the Class II area
would still need to comply with conditions described above.
Switching and Actuation:
Intrinsically safe, waterproof switches or air tight switches are all acceptable.
Powered switching such as motion or presence sensors is sometimes permissible
(check with local officials and electrical engineer), but must be sealed in a dust tight
enclosure. |
Class III
Ignitable fibers might be present in the rooms atmosphere. |
Use equipment as described above
for NEMA Class II areas. |
|
EXPLOSION
PROOF DOOR OPERATORS |
| Series
1000EXP |
Horton
series 1000EXP pneumatic sliding door operator systems are used for
light industrial applications and clean room entrances, where NEMA
classification requires an explosion proof or dust proof door operator
system. Acceptable for use in Class 1, Division 1 or 2, Groups A, B or
C and Class 2, Division 1 or 2, Groups D, E, F or G areas. |
| Series
6-1000EXP |
Horton
series 6-1000EXP pneumatic sliding door operator
systems are used for heavy industrial applications. Acceptable
for use in Class 1, Division 1 or 2, Groups A, B or C and Class 2,
Division 1 or 2, Groups D, E, F or G areas. |
| Series
5000EXP |
Horton
series 5000EXP pneumatic
swing door operator systems. Can be used in conjunction with Von
Duprin exit devices with pneumatic latch retraction. Acceptable
for use in Class 1, Division 1 or 2, Groups A, B or C and Class 2,
Division 1 or 2, Groups D, E, F or G areas. |
|