422ELC
1
05038.R3 11/03
www.protekdevices.com
DIGITAL PROCESS DATA LINE PROTECTOR
Only One Name Means ProTek'TionTM
APPLICATIONS
RS-422 Data Lines
Digital Process Control Loop
Long Line Digital Systems
Digital Transmission
Telemetry Systems
Smoke Detector & Fire Alarm Systems
IEC COMPATIBILITY (EN61000-4)
61000-4-2 (ESD): Air - 15kV, Contact - 8kV
61000-4-4 (EFT): 40A - 5/50ns
61000-4-5 (Surge): 8/20s - 95A, Level 4 (Line-Gnd) & 48A, Level 4 (Line-Line)
FEATURES
LOW CAPACITANCE - 25PF
Designed for EIA Standard RS-422 Data Lines
Permanent Two-Stage 2 Line Pair Protector
Subnanosecond Response Time
Common & Differential Mode Protection
Automatic Reset - Does Not Interrupt Service
Effective Against Lightning, Inductive Switching and ESD
MECHANICAL CHARACTERISTICS
Weight: 142 grams (Approximate)
Flammability Rating UL 94V-0
Device Marking: Logo, Date Code, Terminal Designations & Part Number
DESCRIPTION
The 422ELC is low capacitance, two-stage transient voltage protector that provides
primary and secondary protection against lightning, inductive switching and electro-
static discharge (ESD) transient threats. The first stage diverts the transient current
through the ground terminal return path and the second stage clamps the voltage to a
safe level without interruption of service.
The 422ELC is designed to protect data lines from differential (line-line) and common-
mode (line-to-ground) transients. Terminals 1 & 2 and 3 & 4 for the 422ELC are
designed as line pairs. A transient voltage suppressor is connected across each line
pair for differential mode protection. Each line pair is referenced to ground.
This product can also be used on telephone, signal/data lines, security, timing and
control interface circuits. For most applications, the product should be located as close
as possible to the equipment being protected. A low impedance grounding system is
important to maintain a low voltage clamp between the line-to-ground connection.
Capacitance over the operating voltage range is important. If capacitance is nonlinear,
distortion, loss of data or access to the I/O port can occur (See Figure 1).
05038
422ELC
FIGURE 1
LINEAR CAPACITANCE VS
NON-LINEAR CAPACITANCE
0 2 4 6 8 10
V
OP
- Data Line Operating Voltage - Volts
C - Capacitance - pF
1,000
100
1,0
Industry Standard
Low Capacitance
Solid State Protector
ProTek's 422ELC
2
www.protekdevices.com
05038.R3 11/03
422ELC
DEVICE CHARACTERISTICS
INSTALLATION INSTRUCTIONS
There are five (5) terminals on the
LINE SIDE
and five (5) terminals on
the
EQUIPMENT SIDE
of the 422ELC, 4 data lines and one ground.
Both grounds are connected together internally. A single low impedance
ground is sufficient. Incoming data lines are cut or disconnected from
the equipment to insert the 422ELC product. The incoming lines are to
be connected to the line side terminals as the equipment side lines are
connected to the equipment side terminals. The location of the product
should be as close to the equipment as possible. The 422ELC series is
designed with a short circuit failure mode to give maximum protection. A
fuse, fussable link, or circuit breaker is recommended for each data/
signal line on the input side for those that require an open circuit failure
mode.
Caution:
A low DC resistance ground may not be a good ground.
Lightning contains a broad spectrum of frequencies up to 1 MHz. A low
impedance path to ground at the transient frequencies is necessary. A
ground strap is recommended or a #6 AWG stranded wire. For wire
lengths over 1.5 meters, there may be some excessive line to earth
potential under severe thunderstorm conditions.
30.0
MAXIMUM
CLAMPING
VOLTAGE
Line - Line
500A, 8/20s
V
C
VOLTS
MAXIMUM
CAPACITANCE
@ 0V, 1 MHz
C
pF
MAXIMUM
LINE THRUPUT
RESISTANCE
R
OHMS
12
30.0
1
25
MAXIMUM RATINGS @ 25
0
C
MAXIMUM
CLAMPING
VOLTAGE
Line - Ground
500A, 8/20s
V
C
VOLTS
MAXIMUM
LEAKAGE
CURRENT
@ 12 V
OP
I
D
A
ELECTRICAL CHARACTERISTICS @ 25
0
C Ambient Temperature
Peak Operating Line Voltage (V
OP
)
Operating Line Current (I
O
)
Maximum Transient Voltage
Maximum Transient Current
(8/20s waveform)
Operating & Storage Temperature
Response Time
12V
200mA
20kV
10kA/Wire
40kA/Protector
-55C to 100C
< 1 nanosecond
3
www.protekdevices.com
05038.R3 11/03
422ELC
COPYRIGHT ProTek Devices 2003
SPECIFICATIONS: ProTek reserves the right to change the electrical and or mechanical characteristics described herein
without notice (except JEDEC).
DESIGN CHANGES: ProTek reserves the right to discontinue product lines without notice, and that the final judgement
concerning selection and specifications is the buyer's and that in furnishing engineering and technical assistance,
ProTek assumes no responsibility with respect to the selection or specifications of such products.
PACKAGE OUTLINE & DIMENSIONS
ProTek Devices
2929 South Fair Lane, Tempe, AZ 85282
Tel: 602-431-8101 Fax: 602-431-2288
E-Mail:
sales@protekdevices.com
Web Site:
www.protekdevices.com
INSTALLATION DIAGRAM
422ELC Case Outline
EQUIPMENT
1
2
4
GND
3
2
1
4
GND
3
WARNING:
LINE
3.8" MAX
(95.5mm)
3.25"0.015"
(82.6mm0.38mm)
2.25" MAX
(57.2mm)
Mounting
Hole for #8
Screw
1.19" MAX
(30.2mm)
#6 Screw
0.61" MAX
(15.5mm)
Adhesive Mylar Label
Terminal Screw
1.125"
(30.2mm)
Unprotected Side Protected Side
1
2
GND
3
4
1
2
GND
3
4
(Line Input
T
e
r
m
inal)
Data Line From Outside World
(Equipment T
e
r
m
inal)
T
o
T
r
ansmit/Receiv
e
Circuits
Earth Ground
Earth Ground
Note:
Both ground terminals are common. Use second ground wire
to reduce impedance on long runs to earth ground connections
Terminal Strip
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