At places such as water purification plants, sewage treatment plants and dams, there are often cases where instruments are damaged due to lightning.
This arrester is used for protecting transmitters and receiving instruments from surge voltage induced in transmission
lines due to lightning etc. Two types of arresters, fieldmount type and panel-mount type, are available.
The arrester, using FUJl's Z-trap, offers high performance
and reliability, and is optimum for protecting semiconductor circuits in instruments from surges.
Panel-mount type (PXC)
1. Used as the arrester element is the Z-trap, which was
developed at FUJl's central research laboratory and is already being widely used in products. The Z-trap is a
gapless arrester made from a sintered body which consists mainly of zinc oxide, and offers the following remarkable features.
• An excellent voltage limiting characteristic.
• A large surge absorption capacity despite its small size.
• Can absorb rapidly pulsating surge because of its fast
• Voltage and current characteristics are symmetrical,
so surges of both positive and negative polarity are
equally absorbed.
• Stable against repetitive surge.
• High reliability.
2. Performance is boosted by adding secondary and tertiary
protective circuits made up of resistors and zener diodes
as back-up circuit elements together with the Z-trap. This
provides excellent protection for semiconductors.
3. This is the panel-mount type (PXC) for receiving instrument protection.
The panel-mount type can be wired systematically at the
bottom of the instrument panel together with external
wiring and junction terminal board.
4. Being an exclusive arrester for FUJI instruments the antisurge characteristic of the system instruments and the
excellent protection afforded by the arrester combine to
allow utilizing the system with no worry whatever.
The arrester can also be used with 4 to 20mA signal circuits of other manufacturers instruments.
Synthetic resin, junction terminal
strip structure
Arrester element
FUJI-Z trap
Secondary protective cct. Resistors, zener diodes
Tertiary protective cct.
Working voltage: 27V DC or less (for 4 to 20mA DC)
Wiring method: 2 wire system
Internal resistance:
Between terminals 1–2, 5–6;
10Ω each … total 20Ω
(max. 24Ω)
Discharge starting voltage:
85V DC ± 15%
Protective performance:
Limiting voltage; 50V or less between transmission line
and ground or another transmission line
(at 100A discharge)
Operation delay; nearly 0 µs
Impulse discharge withstand current;
2000A with 8 x 20 µs impulse wave
No. of repetitive discharges;
400 times with 8 x 20 µs impulse wave,
100A discharge current and 15 sec. repeating interval.
Note: Although this is a highly effective arrester, there are no devices that guarantee 100% protection against any type of lightning. From the data collected so far it can be said that the
surge voltage induced by most lightning is done in (10x200) µs
with crest value 5kV. In certain regions it is said to strike over
a hundred times every year. It is probable that protection might
be insufficient against impulses generated due to high voltages in direct lightning.
Error due to addition of arrester:
Less than 0.1%
Grounding system:
Grounding in coupled condition with instrument
Grounding construction JIS class 1 or
special class 3
Ambient temperature:
0 to 45°C
Mounting method:
On copper busbar with two M4 screws
External dimensions (HxWxD):
55 x 70 x 39mm
Approx. 250g
Finish color:
Synthetic resin (black)
Zener diodes
Nov. 22, 2001
Panel-mount type
1 2 3 4 5 6 7 8
P XC 1 0 0 02
Working voltage/signal current
24V DC 4 to 20mA
2-wire system
Cautions on use
(1) PXC has an internal resistance of 20 Ω, so when both arresters are used the wiring resistance becomes 40 Ω.
(2) PXC is intended for signal circuits, but if an arrester for a power supply circuit is necessary, we recommend FUJl's Z-trap.
(3) Be sure to perform grounding correctly. The protected instrument and arrester should be grounded together, while
keeping the grounding resistance as low as possible.
(4) If the commercial frequency induced potential (common mode) to ground exceeds 35V AC, measuring error may result.
Perform wiring so as to avoid as much as possible any induction from power sources or the like.
(5) Before carrying out withstand voltage and insulation resistance tests on instruments or wiring, disconnect the arrester
from the circuit.
1. Product name and code symbol
Caution on Safety
*Before using this product, be sure to read its instruction manual in advance.
Head Office
Gate City Ohsaki, East Tower, 11-2, Osaki 1-chome,
Shinagawa-ku, Tokyo 141-0032, Japan
Instrumentation Div.
International Sales Dept.
No.1, Fuji-machi, Hino-city, Tokyo, 191-8502 Japan
Phone: 81-42-585-6201, 6202 Fax: 81-42-585-6187
Information in this catalog is subject to change without notice.
Printed in Japan