RS PRO Metal Oxide Varistor 2.57nF, Clamping 395V, Varistor 240V

Our RS Pro metal oxide varistors have been designed to meet the abnormal overvoltage requirements outlined in Section 39.4 of the UL1449 standard (4th edition). Under sustained voltage conditions, the Metal Oxide Varistor (MOV) lead that is connected to the thermal link opens. Meeting UL1449 4th edition requirements, these MOVs are ideal for surge protection devices without generating high cost or creating a complicated approach.

When used above their rated specification, traditional MOVs can fail to short circuit conditions or fail to open when exposed to sustained steady state overvoltage. However, the integrated thermal link used in our RS Pro range responds to temperature and voltage. This response ensures that when the MOV exceeds a certain temperature or voltage, the MOV disconnects from the line.

Our range of thermally protected MOVs react instantly to unexpected overvoltage situations and offer an excellent level of protection to components downstream. RS Pro MOVs are wave solderable, helping you to reduce cost by eliminating the rework caused by hand soldering operations.

The thermal link in our MOVs must only be used to provide protection to the varistor in cases of abnormal overvoltage. Never use a thermally protected varistor in series with the load. Our metal oxide varistors are intended for use in UL 1449 compliant surge protection device modules. However, your module design should allow for the possibility that under extreme overvoltage conditions some units may exhibit heating, arcing and venting before opening. We recommend application testing for this range.

Thermally protected
Wave solderable
At normal operating voltages, these MOVs have low leakage current
High surge current rating up to 40 kA
Operating temperature range of -55°C to +85°C
Storage temperature range of -55°C to +125°C
Three leaded options have a fuse on either the second lead or third lead
Patented Products (U.S Patent #6636403 and IE010410)
94V-0 epoxy rating
ISO and TS16949 certification
UL1449, UL1414/CUL recognition
VDE certification

RS Pro thermally protected metal oxide varistors are suitable for a range of applications including:
AC line power supplies
AC panel protection modules
AC power meters
AC-DC power supplies
Transient Voltage Surge Suppressor (TVSS) Products
Surge protected strips
Uninterruptible power supplies
DIN Rails
White goods
Inverters

Our RS Pro metal oxide varistors have an integrated thermal protection device, so care must be taken when soldering the devices into place. These MOVs can be hand soldered or wave soldered. With hand soldering, we recommended heat sinking the leads of the device. With wave soldering, ensure that the preheat stage and solder bath temperatures are closely controlled.