ISOLATED RAIL

ISOLATED

COMMON

BOURNS

MODEL 2027-15-B

GAS DISCHARGE TUBE

EQUIPMENT

COMMON AND/OR

GROUND

COMMON

GROUND

BLDG. 1 BLDG. 2

COMMON

GROUND

EQUIPMENT

COMMON AND/OR

GROUND

Figure 1

BALANCED OR DIFFERENTIAL INTERFACE

(i.e., RS-422)

EQUIPMENT

COMMON AND/OR

GROUND

COMMON

GROUND

BLDG. 1 BLDG. 2

COMMON

GROUND

EQUIPMENT

COMMON AND/OR

GROUND

EQUIPMENT

COMMON AND/OR

GROUND

COMMON

GROUND

BLDG. 1 BLDG. 2

COMMON

GROUND

EQUIPMENT

COMMON AND/OR

GROUND

Figure 3

CURRENT LOOP, 4-20 mA

1800 Series

Data Line Protector

INSTALLATION INSTRUCTIONS

Speciﬁ cations are subject to change without notice.

The device characteristics and parameters in this data sheet can and do vary in different applications and actual device performance may vary over time.

Users should verify actual device performance in their speciﬁ c applications.

Bourns

Part No.

Peak

Signal

Voltage

Series DC

Resistance

Per Line

Max.

Short

Circuit

Current

Recommended

Fuse rating

1810 / 1820-10 10 V 10 Ω 220 mA 200 mA

1810 / 1820-15 15 V 15 Ω 180 mA 150 mA

1811 / 1820-28 28 V 22 Ω 150 mA 125 mA

1812 / 1820-50 50 V 51 Ω 75 mA 75 mA

Bourns

Model 1800 Series Data Line Protectors provide bi-

directional protection. Therefore, they can be used in both

positive and negative supply systems.

Each 1800 Series unit protects one differential pair (see Fig. 1),

or two individual data lines (see Fig. 2), or one current loop (see

Fig. 3). Cable shields can be passed through and may either be

grounded or not grounded at the protector via the grounding link

as shown in Fig. 4.

Place protector(s) as close as possible to the equipment to be

protected.

General

Typical Connections

WARNING: If maximum continuous or short circuit current may

exceed speciﬁ ed values, a current-limiting fuse must

be installed between the power supply or current source and the

equipment side of the protector. See above table.

Bourns

Part No.

Peak

Signal

Voltage

Series DC

Resistance

Per Line

Max.

Short

Circuit

Current

Recommended

Fuse rating

1810 / 1821-10 10 V 10 Ω 350 mA 300 mA

1810 / 1821-15 15 V 15 Ω 300 mA 300 mA

1811 / 1821-28 28 V 22 Ω 250 mA 250 mA

IMPORTANT: Common Ground = Chassis, Power and Earth

Ground. However, when earth grounding of electronic common

is not permissible, protector(s), including rail, may have to be

isolated from earth ground via a Bourns

Model 2027-15-B

Spark Gap as shown in Fig. 4.

Figure 2

UNBALANCED INTERFACE - TWO INDIVIDUAL CIRCUITS

(i.e., RS-232)

Figure 4

WHEN EARTH

GROUNDING IS NOT

PERMISSIBLE

BUSBAR

PLATE

ORILL #29

TAP 8-32 INF-28

9.53

(0.375)

19.05

(0.75)

3.45

(0.136)

DIA.

ORILL #38

2.57

(0.101)

DIA.

ALIGNMENT

48.51

(1.91)

MOUNTING/

GROUNDING

SCREW

95.25

(3.75)

FEED-THRU (E3/L3)

GROUNDING

SCREW

3.18

(.125)

8-32 UNF-2A

44.45

(1.75)

LENGTH

23.62

(0.93)

DIA.

27.94

(1.1)

TS-35 RAIL MOUNTING (See Figure 5)

1. Using the clamp assembly, each protector can be installed or

removed without disturbing other protectors.

2. Protector establishes ground connections with the rail via the

clamp assembly. Tighten screw ﬁ rmly.

3. Rail must be connected to common ground. A solid or

stranded No. 6 AWG tin-plated copper wire is recommended.

Length to be as short as possible and not to exceed 10 feet.

BUS BAR OR PLATE MOUNTING (See Figure 6)

1. Remove clamp assembly from protector.

2. Drill and tap bus bar or plate as shown.

3. Protector establishes ground connection with the bus bar or

plate via the 8-32 mounting/grounding screw. Tighten ﬁ rmly.

4. Bus bar or plate must be connected to common ground.

A solid or stranded No. 6 AWG tin-plated copper wire is

recommended. Length to be as short as possible and not to

exceed 10 feet.

Mounting Instructions

WIRE PREPARATION

Minimum usable wire size is No. 24 AWG. Maximum usable wire

size is No. 14 AWG. Strip insulation to 0.3 inches.

LINE TERMINALS L1, L2, L3

Connect the line (ﬁ eld) wires which are subject to high voltage

surges to protector terminals L1 and/or L2. Connect the cable

shield (if any) to protector terminal L3. L3 is internally connected

to E3.

WARNING: Never connect ﬁ eld lines which are subject to

high voltage surges to the protector equipment terminals

E1 and/or E2. The protector may be damaged.

EQUIPMENT TERMINALS E1, E2, E3

Connect the equipment to be protected to protector terminals E1

and/or E2. Connect the cable shield (if any) to protector terminal

E3 unless it is desirable to ﬂ oat the shield at this point (see

Figures 1 and 2). E3 is internally connected to L3.

SHIELD GROUND OPTIONS (See Figure 4)

The shield is normally grounded at the protector with the E3/L3

grounding link in position A. If the shield is to be ungrounded,

move the grounding link to position B. Re-tighten mounting and

grounding screws ﬁ rmly.

Data Line Connections (See Figures 1-3)

Speciﬁ cations are subject to change without notice.

The device characteristics and parameters in this data sheet can and do vary in different applications and actual device performance may vary over time.

Users should verify actual device performance in their speciﬁ c applications.

10/13

Asia-Paciﬁ c: Tel: +886-2 2562-4117 • Fax: +886-2 2562-4116

Europe: Tel: +41-41 768 5555 • Fax: +41-41 768 5510

The Americas: Tel: +1-951 781-5500 • Fax: +1-951 781-5700

www.bourns.com

1800 Series

Data Line Protector

INSTALLATION INSTRUCTIONS

RAIL

E3/L3

GROUNDING

LINK

18.80

(0.74)

83.31

(3.28)

MOUNTING/GROUNDING

SCREW

FEED-THRU (E3/L3)

GROUNDING SCREW

CLAMP

ASSEMBLY

TS-32 RAIL P/N 36213

28.96

(1.14)

49.02

(1.93)

Figure 5

TS-32 RAIL MOUNTING

Figure 6

RECOMMENDED BUS BAR OR PLATE MOUNTING