Datasheet

“ZNR” Transient/Surge Absorbers
“ZNR” Transient/Surge Absorbers, Type D, Series E
Handling Precautions
In case that a ZNR Surge Absorber (Type D Series E)(hereafter referred to as the ZNR, or product name) is used,
if an abnormality takes place because of peripheral conditions of the ZNR(material, environments, power source
conditions, circuit conditions, etc. in equipment design),  re, electric shock, burn, or product failure may be occur.
The precautions for this product are described below, understand the content thoroughly before usage. For more ques-
tions, contact us.
Safety Precautions
1. Precautions to be strictly observed
1.1 Con rmation of performance ratings
Use the ZNR within its rated range of performance such as the Max. allowable voltage, withstanding surge current , withstanding
energy, impulse life(surge life), average pulse power, and operating temperature range. If used outside the range, the ZNR can
be degrade and have element fracture, which may result in smoking and ignition.
1.2 To avoid accidents due to unexpected phenomena, take the following measures
1) In the event of fracture of the ZNR, its pieces may scatter ; hence, put the case or cover of the set product in place.
2) Do not install the ZNR near combustible substances(polyvinyl chloride wires, resin moldings, etc.). If it is diffi cult to do, install
a nonfl ammable cover.
3) Across-the-line use
When the ZNR is used across a line, put a current fuse in series with the ZNR
(Refer to Item 2.1.1). (4) and Table 1.
4) Use between line to ground
(1) If the case that the ZNR is used between a line to the ground, the short-circuit of the ZNR may not blow the current fuse
because of grounding resistance, which may cause smoking and ignition of the ZNR’s exterior resin. As the measure
against it, install an earth leakage breaker on the power supply side of the ZNR position. If no earth leakage breaker is
installed, use a thermal fuse together wth a current fuse in series. (Refer to Table 1.)
(2) If the case that the ZNR is used between a live part to metal case, an electric shock may develop at a shortcircuit of the
ZNR ; hence, ground the metal case to the ground or keep it from the human body.
2.Application notes
2.1 Pay attention to the following items to avoid the shortened life and failure of the ZNR
1) Circuit conditions
(1) Select a ZNR of which the maximum voltage including fl uctuations in source voltage allows for the maximum
permissible circuit voltage. (Refer to Table 1.)
(2) In cases that surges are intermittently applied at short intervals(for example, in case that the voltage of the noise
simulator test is implemented etc.), do not let them exceed the ZNR’s rated power.
(3) Select a ZNR recommended in Table 1.
<1> Across-the-line use
If possible, use a Part No. marked with
✽
in case of voltage temporarily rises load unbalance of separately-wired
loads, short between hot and neutral-line, open of neutral line in single-phase-three-wired system, and due to
resonance at switching for a capacitive, inductive load.
<2> Used between line to ground
Use a different Part No. from “Across-the-line use” as table 1, because of raising voltage in case of “Line
to Ground Fault”.
Use a Part No. marked with
✽✽
in table 1, in case of the insulation resistance test(500 VDC) for equip ment.
When using a Part of the varistor voltage that the insulation effi ciency examination can not be cleared, there
is a case where the surge absorber can be done by removing it from the circuit depending on the circuit
condition(Refer examination of Japan Domestic Safety Regulations).
Use a Part No. marked with
✽✽✽
in table 1, in case of the withstanding voltage test(1000 VAC or 1200 VAC)
for equipment.
Aug. 201303
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