Owner`s manual

vENtiLAtiON NOmOGRAPH
HAzARdOUS LOCAtiON iNfORmAtiON
Reference: Explosion-Proof Blowers: 9503, 9515-01, 9513-05, 9514-05, 9514-06, 9509-01, 9538, 9538-15, 9538-25 and 9525-01* National Electrical Code (NEC)
A hazardous location is an area where the possibility of explosion and fire is created by the presence of flammable gases, vapors, dusts, fibers or flyings.
NOTE: Fibers and flyings are not likely to be suspended in the air, but can collect around machinery or on lighting fixtures
and where heat, a spark or hot metal can ignite them.
* WARNING: Explosion-proof blowers must be used with statically conductive ducting.
VENTILATION INFORMATION
5
8
10
12
15
18
20
23
25
28
30
35
45
40
50
55
60
70
80
90
100
120
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
This reference chart represents
7 complete air exchanges (VOL).
Purging Time
(in minutes)
Manhole Volume
(cubic feet)
Effective Blower
Capacity (CFM)
1500
1400
1200
1
100
1000
800
700
600
500
300
1300
900
400
USE OF ALIGNMENT
CHART:
1. Place straightedge
on manhole volume
(left scale).
2. Place other end of
straightedge on blower
capacity (right scale).
3. Read required purging
time, in minutes, on
diagonal scale.
4. If two blowers are used,
add the two capacities,
then proceed as above.
5. When toxic gases are
encountered, increase
purging time 50%.
6. Effective blower capacity
is measured with one or
two 90° bends in standard
15-foot blower hose.
See chart.
CONFINED BLOWER
SPACE CUBIC FEET PER
VOLUME MIN. (CFM)
(CUBIC FEET) OUTPUT NEEDED*
1000 333
2000 667
3000 1000
4000 1333
5000 1667
6000 2000
7000 2333
8000 2667
9000 3000
10000 3333
*Take into account 90º bends of ducting. See
specifications under each
blower description.
Scan this code to access our
Blower CFM calculator.
VENTILATION AIR
EXCHANGE CHART
Allegro Industries recommends air
exchange at a rate of at least
20 times per hour.
CLASS III
(NEC-500-7)
Those areas in which there are easily ignitable fibers
or flyings present, due to type of material being
handled, stored, or processed.
GROUPS
(NEC-500-3)
The gases and vapors of Class I locations are
broken into four groups by the code: A, B, C,
and D. These materials are grouped according
to the ignition temperature of the substance,
its explosion pressure and other flammable
characteristics. The dust locations of Class II are
designated E, F, and G. These groups are classified
according to the ignition temperature and the
conductivity of the hazardous substance.
NOTE: For detailed group descriptions refer to NEC-500-3.
TYPICAL CLASS III LOCATIONS
•Textilemills,cottongins,cottonseedmillsand
flax processing plants.
•Anyplantthatshapes,pulverizesorcutswood
and creates sawdust or flyings.
CLASS II
(NEC-500-6)
Those areas made hazardous by the presence
of combustible dust.
DIVISION 2
(NEC-500-5, 6, 7)
In the abnormal situation, material is expected
to be confined within closed containers or
closed systems and will be present only through
accidental rupture, breakage or unusual
faulty operation.
TYPICAL CLASS II LOCATIONS
•Grainelevators,ourandfeedmills.
•Plantsthatmanufacture,useorstore
magnesium or aluminum powders.
•Plantsthathavechemicalormetallurgical
processes, producers of plastics, medicines,
and fireworks, etc.
•Producersofstarchorcandies.
•Spice-grindingplants,sugarplantsand
cocoa plants.
•Coalpreparationplantsandother
carbon-handling or processing areas.
CLASS I
(NEC-500-5)
Those areas in which flammable gases or vapors
may be present in the air in sufficient quantities to
be explosive or ignitable.
DIVISION I
(NEC-800-5, 6, 7)
In the normal situation, hazard would be
expected to be present in everyday production
operations or during frequent repair and
maintenance activity.
TYPICAL CLASS I LOCATIONS
•Petroleumreneries,andgasolinestorageand
dispensing areas.
•Industrialrmsthatuseammableliquidsindip
tanks for parts cleaning or other operations.
•Petrochemicalcompaniesthatmanufacture
chemicals from gas and oil.
•Drycleaningplantswherevaporsfromcleaning
fluids can be present.
•Companiesthathavesprayingareaswherethey
coat product with paint or plastics.
•Aircrafthangersandfuelservicingareas.
•Utilitygasplants,andoperationsinvolving
storage and handling or liquefied petroleum gas
or natural gas.
blowers
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