The Littelfuse TMOV and iTMOV thermally protected varistors represent a
new development in integrated circuit protection (patent pending). Both
versions are comprised of radial leaded MOVs (Metal Oxide Varistors)
with an integrated thermally activated element designed to open in the
event of overheating due to the abnormal over-voltage, limited current,
conditions outlined in UL1449.
The iTMOV varistor differs from the TMOV varistor by the inclusion of a
third lead for the purpose of indicating that the MOV has been disconnect-
ed from the circuit. This lead facilitates connection to monitoring circuitry.
The TMOV and iTMOV varistors offer quick thermal response due to the
close proximity of the integrated thermal element to the MOV body. The
integrated configuration also offers lower inductance than most discrete
solutions resulting in improved clamping performance to fast over-voltage
transients. Additionally, TMOV and iTMOV varistors are wave solderable,
thus simplifying end product assembly by reducing the expense and
rework associated with hand soldering operations.
The TMOV and iTMOV varistors are both recognized surge suppression
components to UL 1449. The TMOV and iTMOV varistor’s integrated
thermal element, in conjunction with appropriate enclosure design, helps
facilitate TVSS module compliance to UL1449 for both cord connected
and permanently connected applications.
TMOV and iTMOV varistors are compatible for use with industry standard
wave-soldering processes or recommended hand-soldering methods.
Features
• Patent Pending Integrated Thermal Protection Device
• Designed to facilitate compliance to UL1449 for TVSS product
• High peak surge current rating up to 10kA
• Wave solderable
• Standard lead form and spacing option
• Low Leakage
• -55°C to +85°C Operating Temperature Range
• Three-lead version available for indication purposes.
AGENCY APPROVALS:
CSA recognized.
20mm Devices-Recognized under the components program of Underwriters
Laboratories UL1449 and UL1414. Includes selected tests from UL1020,
regarding thermal cutoffs for devices with voltage ratings up to 420VAC.
14mm Devices-Devices are approved as an MOV to UL1449 and UL1414.
Approval to selected UL1020 requirements pending. Devices (14mm and
20mm) with ratings greater than 420VAC are not affected by these abnormal
voltage conditions.
Accelerated Aging Testing-14 and 20mm devices
comply with Acclerated Aging Test requirements per. ANSI/IEEE C62.11 and
may be used in secondary surge arrestors without repeating this test.
Documented in UL file E75961.
AGENCY FILE NUMBERS: ULE56529 (UL1414)
ULE75961 (UL1449)
CSA LR91788
Applications
• TVSS Products
• AC Panel Protection Modules
• AC Line Power Supplies
• Surge Protected Strip Connectors
• AC Power Meters
• Relocatable AC Power Taps
• GFCI (Ground Fault Current Interupter)
• UPS (Uninterruptable Power Supply)
• White Goods
• Plug-in TVSS
• Inverters
• AC/DC Power Supplies
