Gems Sensors & Controls 22445, 25872, 25873, 41705, 41715 Instruction Bulletin

Example (Cont.)

Because of the low sensitivity of the device, maximum lead length is limited to a total switch
lead resistance of 200 ohms.

GROUP

A & B

C

D

CAPACITANCE

1 uf

1 uf

1 uf

INDUCTANCE

.50 mh

.50 mh

.50 mh

D. Whenever possible, the actual measured parameters should be used in making

the determination of allowable length.

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.

F. Non-intrinsically safe wiring cannot be run in conduit or open raceways together

with intrinsically safe wiring.

G. Refer to Fig. 8 for detailed connection to terminal studs. All hardware, including

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

"slo-blo". 120 VAC for 120 V line voltage; 250 VAC for 240 volts.

I. Protective cover (supplied) must be in place over sensor-connected terminals of

the PAK after wiring has been completed (See Fig. 9)

Fig. 8

Recommended Method of Connection to Electrical Terminals

Terminal Lug.

HEX

Nut

Anti-Vibrational

Lockwasher

(Closed-Ring Type)

Terminal Stud

Tighten Assembly to Between
3 and 5 In. Lbs.

All terminal hardware (including
lug) supplied with unit.

Notes

Fig. 9

Mounting of Protective Cover over Sensor-Connected Terminals of Unit

SAFE-PAK Models 22445, 25872, 25873
Latching SAFE-PAK Models 41705, 41715
HI-LO PAK Models 38705, 38710, 38715, 38720

Instruction Bulletin No. 54477

For use as an "intrinsically safe switch circuit" and in hazardous locations with non­voltage producing sensors. When SAFE-PAK installation is in accordance with this guide,
these field sensors are suitable for Class I; Divisions 1, 2; Groups A, B, C and D and Class
II; Division 2; Groups E, F and G, as defined by Article 500 of the National Electric Code.

IMPORTANT! Read carefully and completely before installing or connecting SAFE­PAK, Latching SAFE-PAK or HI-LO PAK units.

*** Warning: To prevent ignition of flammable or combustible atmospheres, disconnect

power before servicing.

1. Associated Equipment - Caution: The SAFE-PAK must be mounted outside the
hazardous area. Only the switch or sensor terminals provide an intrinsically safe
switch circuit (see Fig. 1, Fig. 2, Fig 3 or Fig. 4). [Exia] means associated equipment:
"Appareillage connexe", located in safe area.

Connection Diagram: Gems SAFE-PAK Models

Note

For 120V application,
only one fuse is required
in the ungrounded circuit
of the input line.

Input

VAC

Fig. 1.

FUSE F1

FUSE F1

SAFE-PAK

Sensor Switch

LOAD

[Exia]

Non-Hazardous

Location

Hazardous

Location

P/N 54477

Rev. AE

Stud

Cover

Terminals

Nylon

Stud Nuts

Stud

Cover

Terminals

LATCHING SAFE-PAK SAFE-PAK

Nylon

Stud Nuts

(High)

N.O. Dry

(Low)

N.O. Dry

Circuit for Pump-Down Operation

Fig. 2.

Hazardous

Location

S2

S1

Non-Hazardous

Location

On

A
C

Com

L
O
A
D

Off

atching

SAFE-PAK

Fuse F1

VAC (Hot)

Com

Load