Omega Products SBG54803 Installation Manual

SBG54803 Solid-State Relays
for Intrinsic Safety Use

Instruction Sheet M1775/0594

DESCRIPTION

The OMEGA® SBG54803 Dual Channel Zener Barrier is a
solid-state, energy-limiting device for transmitting direct cur­rent signals of less than 20V and less than 100mA in an in­trinsically safe manner. The unit is designed to be used in
conjunction with indicating equipment in hazardous areas
defined as Class I, Division 1, and inclusive of Groups A
through D. This zener barrier is used where circuit common
is earth-ground-referenced.

THE AMBIENT TEMPERATURE OPERATING RANGE
OF THIS DEVICE IS 0° TO 60°C. (+32° TO +140°F).

UNPACKING

Remove the Packing List and verify that you have received all
equipment. If you have any questions about the shipment,
please call the OMEGA Customer Service Department at
1-800-622-2378 or [phone]. When you receive the
shipment, inspect the container and equipment for any signs of
damage. Note any evidence of rough handling in transit.
Immediately report any damage to the shipping agent.

NOTE

The carrier will not honor any claims unless all shipping material
is saved for their examination. After examining and removing
contents, save packaging material and carton in the event
reshipment is necessary.

Important: Read carefully and completely before
installing or connecting the solid-state relays.

CONSIDERATIONS FOR INSTALLATION AND USE

Only one sensor per channel may be connected to a barrier
(See Figure 1).

Hazardous

Area

Sensor

Non-Hazardous Area

Zener

Barrier

6

8

5

7

Stud Cover Must Be In

Place When Barrier Is In Use

Earth Ground Bracket

2

4

1

3

Fig. 1. Installation Diagram

(One Sensor Shown)

All barriers used for multiple barrier
mounting must be of the same polarity.

Mounting

Panel

Important

At Two Points

(See Fig. 3)

Term.

Equip.

Non-Intrinsically
Safe Wiring
To Receiver

Zener

Barriers

The barrier and receiving station must be located in a non­hazardous location.

The mounting bracket on the barrier must be connected to an
earth ground from both mounting points and two lines for
redundancy. The grounding should be adequate for conduc­tion of line generated fault currents. The resistance of either
line to earth ground should be maintained at less than one
ohm.

To serve multiple tank installations, additional barriers may
beplaced in an enclosure using a common earth ground
(See Figure 2). In this enclosure, the intrinsically safe wiring
should be segregated from non-intrinsically safe wiring by
independent raceways, wiring trays or other adequate means
to insure the integrity of the installation. Additionally, when
internal terminations are used, intrinsically safe wiring and
non-intrinsically safe wiring should not be adjacent or
arranged in such a way as to create the potential to miswire
or bypass the barrier during servicing or testing. (See

typical installation depicted in Figure 2.)

Common, commercially available
signal wire may be used for field
wiring and distances of up to
1000 ft. are acceptable using
twisted wire. Characteristics of
the signal line should not be

Product must be maintained and in­stalled in strict accordance with the
National Electrical Code. Failure to
observe this warning could result in
serious injuries or damages.

WARNING

modified by addition of capacitive
or inductive components.

Intrinsically

Safe Wiring

To Transmitter

Rail**

**6" Mounting Rail:

SBG-RAIL-6
12" Mounting Rail:

SBG-RAIL-12
18" Mounting Rail:

SBG-RAIL-18

Earth Ground

(See Fig. 3)

Resistance to ground must be
from bracket to earthing member
to insure integrity of system.
(Must be below one ohm.)

Fig. 2. Multiple Barrier Mounting

SBG61783 MountingClip

(Optional)

Zener Barrier

#10 Screw

#10 Lockwasher*

#10
Nut

#10 Lockwasher*

Mounting

Plate

Each sensor must have its own ground return wire to pin 5.

The governing parameters for various groups are as follows:

GroupGroup

Group

GroupGroup

Hydrogen

& Acetylene

Ethylene

Methane

Note: *Values are for any one loop in the hazardous area.
(i.e., Terminals 7 to 5 or 8 to 5)

A & B

C

D

CapicitanceCapicitance

Capicitance

CapicitanceCapicitance

0.4 µF

1.2 µF

3.2 µF

**

*

**

InductanceInductance

Inductance

InductanceInductance

0.9 mH

5.0mH

10.0mH

**

*

**

Field Testing of Barrier

A. Never conduct tests while circuit is active. The use of
instruments between input and output terminals will
bypass the barrier.

Detail of Earth Grounding

*Lockwasher

Nut

Nut

1. Grounding Hardware to be #8 or larger and stainless
steel

2. *(Lockwashers to be internal or external tooth type)

Screw

Notes

Mounting

Plate

*Lockwasher

Terminal Lug

*Lockwasher

Fig. 3. Details of Mounting and Grounding

B. All testing is to be done with circuit inactive using the

following instruments:

1. Ohmmeter with resolution down to less than 1 ohm.

2. D. C. power supply with an output of 0 to +25 VDC.

3. D. C. voltmeter.
C.

Test performance (See Fig. 5)

Step 1:

Disconnect all leads to unit under test except to the

earth

grounding mounting tabs.

Step 2:

a. Measure the resistance between terminals 1 & 7 and then
2 & 8. This resistance should be 250 ohms ±5% (± instru­ment tolerance).
b. Measure the resistance between terminals 5 & 3 and then
terminal 5 and the mounting tab. Both readings should be
below one ohm.
c. Apply 24 volts to terminals 7(+) and 5 (common). Then

read the voltage between the terminals 1 (+) and 3 (common)

*.

This voltage must be between 18.5 and 21.5 volts. In the
same fashion, conduct this same test with the voltage con­nected across 8 (+) and 5 (common) and measure the output
across 2 (+) and 3 (common).
d. Connect an ohmmeter between the mounting tab (not the
mounting screw) and the earth ground reference. The read­ing must be less than one ohm. The barrier must pass all

parts of this test or it is unacceptable.

* The fuses located in the circuits 7-1 and 8-2 are

rated at 100mA. Therefore, care should be exercised
in testing this device so that no accidental current
greater than 100mA enters or leaves terminal 1 or 2.

Note: Every effort should be made to keep these barriers clean and
free of contaminating atmospheres. A periodic check should be made
to verify that they are in good condition, physically and electrically.

Mounting

Tab

1-5/8"

(41.3 mm)

2-3/4"

(69 mm)

6" (152.4 mm)

5-1/2" (139.7 mm)

Output Terminals No. 6-32 Thd.

8

8

5

7

7/22" (5.6 mm) Dia.

3 Mtg. Holes

4-3/4" (120.7 mm)

Housing

Fig. 4. Dimensions

4

2

1

7

Input Terminals

No. 6-32 Thd.

Rail-Mounting

(Optional)

Hazardous

Area

Sensor

DC Input to

MM

odelodel

M

odel

odelodel

MM

NumberNumber

Number

NumberNumber

SBG54803SBG54803

SBG54803

SBG54803SBG54803

Housing material is blue Lexan.

Barrier, Max.

Voltage

20

7

5, 6

8

Fuse Rating
Current, mA

100

Non-Hazardous

Area

120Ω

120

Ω

20 V

20 V

120Ω 120Ω

Zener Barrier

Fig. 5. Intrinsically Safe Loop Schematic

Series

Signal

Polarity

Positive

Resist.

10Ω

20 V
20 V

10Ω

1

3, 4

2

Table 1. Specifications

Applications

Groups

Class i & II, Div 1, 2

Ω

270

Groups A, B, C, D

Power

Supply

Logic

Reactive Limits

Capacitance

µµ

µF

µµ

0.4

Indication

Receiver

Inductance

mHmH

mH

mHmH

0.9

Input
Power

Ambient

Oper.

Temp.

0° to +60°C

Weight

495g

P/N 158351P/N 158351

P/N 158351

P/N 158351P/N 158351