Example (Cont.) SAFE-PAK Models 22445, 25872, 25873 Because of the low sensitivity of the device, maximum lead length is limited to a total switch Latching SAFE-PAK Models 41705, 41715 lead resistance of 200 ohms. HI-LO PAK Models 38705, 38710, 38715, 38720 GROUP CAPACITANCE INDUCTANCE A & B 1 uf .50 mh Instruction Bulletin No. 54477 C 1 uf .50 mh D 1 uf .50 mh For use as an "intrinsically safe switch circuit" and in hazardous locations with non- voltage producing sensors. When SAFE-PAK installation is in accordance with this guide, D. Whenever possible, the actual measured parameters should be used in making these field sensors are suitable for Class I; Divisions 1, 2; Groups A, B, C and D and Class the determination of allowable length. II; Division 2; Groups E, F and G, as defined by Article 500 of the National Electric Code. E. Shielded cable is not required; but if used in the application, the shield must be returned to ground - the same as the PAK mounting bracket. IMPORTANT! Read carefully and completely before installing or connecting SAFE- F. Non-intrinsically safe wiring cannot be run in conduit or open raceways together PAK, Latching SAFE-PAK or HI-LO PAK units. with intrinsically safe wiring. *** Warning: To prevent ignition of flammable or combustible atmospheres, disconnect G. Refer to Fig. 8 for detailed connection to terminal studs. All hardware, including power before servicing. terminal lugs, is supplied with unit. H. Fusing of the SAFE-PAK to be in accordance with Fig. 1. Fuse F1 to be 6 amps 1. Associated Equipment - Caution: The SAFE-PAK must be mounted outside the "slo-blo". 120 VAC for 120 V line voltage; 250 VAC for 240 volts. hazardous area. Only the switch or sensor terminals provide an intrinsically safe I. Protective cover (supplied) must be in place over sensor-connected terminals of switch circuit (see Fig. 1, Fig. 2, Fig 3 or Fig. 4). [Exia] means associated equipment: the PAK after wiring has been completed (See Fig. 9) "Appareillage connexe", located in safe area. Fig. 1. Fig. 8 Connection Diagram: Gems SAFE-PAK Models Recommended Method of Connection to Electrical Terminals FUSE F1 Terminal Lug. Input HEX (Closed-Ring Type) LOAD Nut Note VAC Terminal Stud Anti-Vibrational For 120V application, FUSE F1 Lockwasher [Exia] only one fuse is required in the ungrounded circuit SAFE-PAK Notes Tighten Assembly to Between of the input line. Non-Hazardous 3 and 5 In. Lbs. Location All terminal hardware (including lug) supplied with unit. Hazardous Location Fig. 9 Mounting of Protective Cover over Sensor-Connected Terminals of Unit Sensor Switch Stud Fig. 2. Stud Cover Cover Circuit for Pump-Down Operation Nylon Nylon Stud Nuts Stud Nuts Terminals Non-Hazardous Hazardous Terminals Location Location (High) Fuse F1 N.O. Dry VAC (Hot) On A C S2 LATCHING SAFE-PAK SAFE-PAK Com Com L O A D Off Load Latching (Low) SAFE-PAK S1 N.O. Dry P/N 54477 Rev. AE Fig. 5 Fig. 3 Multiple PAK Units Grouped on Common Earth-Grounded Mounting Plate Circuit for Pump-Up Operation Non-Intrinsically Earth Ground Safe Wiring (2 Places) Non-Hazardous Hazardous Location Location Common (Low) Earth-Grounded Fuse F1 N.C. Dry Mounting Plate PAK Units VAC (Hot) On A C S1 Com Com L O A D Off Load (High) S2 N.C. Dry Latching Resistance to ground SAFE-PAK must be from bracket to earthing member to insure Intrinsically Safe integrity of system (must Wiring To Sensors be below one ohm). Fig. 4 Note: All intrinsically safe wiring must be segregated from non-intrinsically safe Circuit for HI-LO PAK Operation wiring and shall have a minimum insulation thickness of .010". AC LOAD Fig. 6 Fig. 7 Unit Mounting Detail Mounting Plate Grounding Detail AC LOAD SAFE-PAK GEMS Screw  HI-LO PAK Mounting *Lockwasher Plate #10 Screw HI COM LO Non-Hazardous Area *#10 Lockwasher Terminal Lug Hazardous Area *Lockwasher Nut *#10 Lockwasher Mounting Plate HI LO #10 Nut Notes 1. Grounding Hardware to be #8 or larger and Stainless Steel. COM Note 2. *Lockwashers to be internal or external tooth type. 1. *Lockwashers to be internal or external tooth type. Probes in Container or Tank 3. Installation of Sensor Switch and Running of Field Wiring 2. Mounting and Enclosure Considerations A. Field wiring of intrinsically safe circuits is to be segregated from non-intrinsically safe B. The conductors of the intrinsically safe circuit should be sealed in a rigid metal wiring by use of suitable barriers, separate wireways or trays (See Fig. 5). Wire conduit at the point where the wiring enters the hazardous area. The wiring and insulation to be .010" minimum. contacting device should be such that conductive dusts in the area will not close the B. Intrinsically safe and non-intrinsically safe connection points should be located circuit in place of the contacts. sufficiently apart to prevent any possibility of bypassing or miswiring during installation or servicing of equipment. C. Hazardous area field wiring will store energy due to distributed capacitance and C. The enclosure shall contain a cautionary statement as follows: "CAUTION: ANY SUBSTITUTION OF COMPONENTS MAY IMPAIR INTRINSIC SAFETY". inductance in proportion to its length. It is therefore recommended that the characteristics D. The PAK mounting bracket must be grounded to insure intrinsic safety. (available from the manufacturer) of the cable be known and judged against the length of Resistance between bracket and ground electrode should be below one ohm. run and atmosphere of exposure. The following conservative chart is presented as a (See Fig. 6 and Fig. 7 for recommended selection of grounding hardware and guideline in determining the limits of reactance for signal loops in the hazardous area refer to Article 250 of the National Electrical Code for methods and practices.) wiring for the SAFE-PAK series. 3. Installation of Sensor Switch and Running of Field Wiring Example: Typical values of capacitance for a twisted pair of copper wires is between A. The nature of the sensor switch must be that it is a non-voltage-producing, essen- 20 and 60 pf per foot. Inductance of a typical twisted pair is between 0.10 and 0.20 tially resistive device, containing no energy-storing components. uh/ft., thus making a cable run in this example essentially determined by the inductance.