|
Important
Notes About 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.
- Always use explosion
proof pneumatic or explosion proof electro-pneumatic operators
in all Class I areas. Horton Automatics manufactures
pneumatic operators for sliding and swinging doors.
Please contact us for specific details.
|
|
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. |
|
|
