ST-22445 Gems Sensors Inc, ST-22445 Datasheet - Page 2

• Manufacturer Part Number: ST-22445
• Description: SAF PAK 95-135 VAC
• Manufacturer: Gems Sensors Inc

2.
3. Installation of Sensor Switch and Running of Field Wiring
C. The enclosure shall contain a cautionary statement as follows: "CAUTION:
D. The PAK mounting bracket must be grounded to insure intrinsic safety.
A. The nature of the sensor switch must be that it is a non-voltage-producing, essen-
B. Intrinsically safe and non-intrinsically safe connection points should be located
A. Field wiring of intrinsically safe circuits is to be segregated from non-intrinsically safe
Mounting and Enclosure Considerations
(See Fig. 6 and Fig. 7 for recommended selection of grounding hardware and
refer to Article 250 of the National Electrical Code for methods and practices.)
Resistance between bracket and ground electrode should be below one ohm.
ANY SUBSTITUTION OF COMPONENTS MAY IMPAIR INTRINSIC SAFETY".
tially resistive device, containing no energy-storing components.
insulation to be .010" minimum.
sufficiently apart to prevent any possibility of bypassing or miswiring during
installation or servicing of equipment.
wiring by use of suitable barriers, separate wireways or trays (See Fig. 5). Wire
N.C. Dry
N.C. Dry
(High)
( L o w )
Hazardous
Location
AC
S1
Circuit for HI-LO PAK Operation
Circuit for Pump-Up Operation
S2
Probes in Container or Tank
HI
HI
HI-LO PAK
Non-Hazardous
AC
GEMS
COM
Fig. 3
Fig. 4
Location
Com
Off
COM
On
LOAD
    
SAFE-PAK
LO
Latching
LO
A
C
L
O
A
D
Non-Hazardous Area
Hazardous Area
Load
LOAD
Fuse F1
VAC (Hot)
Com
3. Installation of Sensor Switch and Running of Field Wiring
B. The conductors of the intrinsically safe circuit should be sealed in a rigid metal
C. Hazardous area field wiring will store energy due to distributed capacitance and
Note: All intrinsically safe wiring must be segregated from non-intrinsically safe
wiring and shall have a minimum insulation thickness of .010".
SAFE-PAK
Mounting Plate
1. *Lockwashers to be internal or external tooth type.
guideline in determining the limits of reactance for signal loops in the hazardous area
Example: Typical values of capacitance for a twisted pair of copper wires is between
20 and 60 pf per foot. Inductance of a typical twisted pair is between 0.10 and 0.20
uh/ft., thus making a cable run in this example essentially determined by the inductance.
contacting device should be such that conductive dusts in the area will not close the
circuit in place of the contacts.
inductance in proportion to its length. It is therefore recommended that the characteristics
(available from the manufacturer) of the cable be known and judged against the length of
wiring for the SAFE-PAK series.
Earth-Grounded
conduit at the point where the wiring enters the hazardous area. The wiring and
run and atmosphere of exposure. The following conservative chart is presented as a
Multiple PAK Units Grouped on Common Earth-Grounded Mounting Plate
Mounting Plate
Common
Unit Mounting Detail
Earth Ground
Intrinsically Safe
Wiring To Sensors
(2 Places)
Fig. 6
Note
#10 Screw
#10 Nut
*#10 Lockwasher
*#10 Lockwasher
Fig. 5
1. Grounding Hardware to be #8 or larger and Stainless Steel.
2. *Lockwashers to be internal or external tooth type.
Mounting Plate Grounding Detail
Mounting
Plate
*Lockwasher
Resistance to ground
must be from bracket to
earthing member to insure
integrity of system (must
be below one ohm).
Non-Intrinsically
Fig. 7
Safe Wiring
Notes
PAK
Screw
Units
Nut
Terminal Lug
*Lockwasher