TMOV25SP385M Littelfuse Inc, TMOV25SP385M Datasheet - Page 8

• Manufacturer Part Number: TMOV25SP385M
• Description: TMOV VARISTOR PB FREE 25S
• Manufacturer: Littelfuse Inc
• Series: iTMOV®r

Specifications of TMOV25SP385M

• Varistor Voltage: 682V
• Current-surge: 20kA
• Number Of Circuits: 1
• Maximum Ac Volts: 385VAC
• Energy: 430J
• Package / Case: Disc 25mm 3-Lead
• Suppressor Type: Varistor
• Peak Surge Current @ 8/20µs: 20000A
• Varistor Case: 25mm DISC
• Clamping Voltage Vc Max: 1010V
• Peak Energy (10/1000us): 430J
• Voltage Rating Vdc: 682V
• Voltage Rating Vac: 385V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Maximum Dc Volts: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Product Selection Worksheet
Step 2. Calculate voltage value.
Step 1. Determine the circuit’s operating parameters.
(complete as much of the following information as possible).
1-a. Source and path of the transient
1-b. Normal operating voltage of protected device
1-c. Tolerance of normal operating voltage (1-b)
1-d. Max. allowable voltage of protected device
1-e. Maximum expected surge current and number of hits
(Specify 8x20μs waveform equivalent of surge current)
1-f. Maximum energy applied to device in surge event
1-g. Maximum power applied to device in surge event
1-h. Maximum allowable varistor capacitance (@1kHz; 0V
bias)
will not impair the functionality of the circuit)
1-i. Required safety standards
(Name of standards required, such as UL, CSA, VDE, etc.)
2-a. The required varistor voltage value should be equal to:
If the tolerance is not known, multiply the operating voltage of
protected equipment or device by 1.10 to 1.25 (i.e. 10–25% above
operating voltage value).
____ Operating voltage AC (V) x 1.414 = ______________________
(1.10 to 1.25) = _____________ Required varistor voltage (V)
the operating voltage of the protected equipment or device*
____Operating voltage of equipment or device (V
________Operating voltage of equipment or device (V
(This is the maximum capacitance of the varistor device that
If the operating voltage is in AC (V
________ Source
________ (V
________ (V)
________ (V
________ (A)
________ (Joules) (E=1.4xVxIxT)
________ (W) (P=VxI)
________ (pF)
_________Tolerance (V) = _____________________
the tolerance of the operating voltage.
AC
AC
) , or ________ (V)
) or ________ (V)
or ________ Unknown
________ Path
________ (# of hits)
- or -
x
+
+
Required varistor voltage (V)
Operating voltage (V)
RMS
RMS
RMS
) convert to V
DC
DC
DC
DC
DC
.
)
Revision: November 5, 2009
RMS
Varistor Products
)
DC
DC
4
Step 3. Guidelines for Selecting a Varistor
If a response to one of the requirements below is "False," refer
to appropriate corrective action notes (A-F) at bottom of list:
3-a. Varistor voltage value - Tolerance of varistor ≥ Required
varistor voltage value (2-a)
3-b. Varistor maximum clamping voltage value Maximum
allowable voltage of protected equipment or device (1-d)
(Max. current should be less than or equal to the current at which
maximum clamping voltage is measured).
3-c. Varistor maximum peak current value Maximum expected
surge current (1-e)
Note: If surge current waveform is not 8 x 20μs, use Pulse
Lifetime Ratings curves.
3-d. Varistor maximum energy rating Maximum energy
applied to system (1-f)
3-e. Varistor maximum rated power Maximum power applied
to system (1-g)
3-f. Varistor capacitance Maximum allowable system
capacitance (1-h)
Corrective action notes:
A. Select next varistor on the list (i.e. next varistor with
increasing varistor voltage value) and then re-verify 3-a.
B. Select previous varistor on the list (i.e. previous varistor with
decreasing varistor voltage value) and then re-verify 3-b.
C. Select next varistor diameter level and then re-verify 3-c.*
D. Select next varistor diameter level and then re-verify 3-d.*
E. Select next varistor diameter level and then re-verify 3-e.*
F . Select lower varistor diameter level and then re-verify 3-c,
3-d, 3-e and 3-f.*
* If varistor voltage is below 82V, selecting an 82V ROV may
be preferable over a higher diameter part.
Step 4. Verify the following system conditions.
4-a. Leakage current of the selected varistor is appropriate for
the circuit ______True ______False
4-b. Verify the performance of the varistor under fault
conditions ______Verified
Users should Independently evaluate the suitability of, and test
each MOV device in their application for safety and suitability
with the end application.
Please refer to www.littelfuse.com for current information.
Specifications are subject to change without notice.
______True ______False (A)
______True______False (B)
______True ______False (C)
______True ______False (D)
______True ______False (E)
______True ______False (F)
©2009 Littelfuse, Inc.