Littelfuse TCMOV Varistor Series - Manual (Page 6)

© 2014 Littelfuse, Inc. 236
Revised: January 16, 2014
Varistor Products
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/tcmov34s.html for current information.
TCMOV Varistor Series
Thermally Protected Varistors > TCMOV Series
UL 1449
An Underwriters Laboratory standard covering the safety
requirements for Surge Protective Devices intended for
permanently connected, cord-connected and direct plug-in
applications.
SCCR
The suitability of an Surge Protective Device for use on an
AC power circuit that is capable of delivering not more than
a declared rms symmetrical current at a declared voltage
during a short circuit condition.
Maximum Non-Repetitive Surge Energy (W
TM
)
This is the maximum rated transient energy which may be
dissipated for a single current pulse at a specified impulse
duration, with the rated RMS voltage applied, without
causing device failure.
Nominal Voltage (V
N(DC)
)
This is the voltage at which the device changes from the
off (standby state) to the on (clamping state) and enters
its conduction mode of operation. The voltage value is
usually characterised at the 1mA point and has a specified
minimum and maximum voltage range.
Term Definitions
Rated AC Voltage (V
M(AC)RMS
) – MCOV
This is the maximum continuous sinusoidal RMS voltage
that may be applied. This voltage may be applied at any
temperature up to the maximum operating temperature of
the device.
Maximum Non-Repetitive Surge Current (I
TM
)
This is the maximum peak current which may be applied
for a single 8/20µs impulse, with rated line voltage also
applied, without causing device failure. The pulse can
be applied to the device in either polarity with the same
confidence factor.
Nominal Discharge Current (I
N
)
Peak value of the current, selected by the manufacturer,
through the SPD having a current waveshape of 8/20µs
where the SPD remains functional after 15 surges.
Voltage Protection Rating (V
PR
)
A rating selected from a list of preferred values as given
in UL 1449 and assigned to each mode of protection. The
value of VPR is determined as the nearest highest value
taken from UL 1449 to the measured limiting voltage
determined during the transient-voltage surge suppression
test using the combination wave generator at a setting of
6kV, 3kA.
Application Example
TCMOV Switch Voltage DC Current (Amps) Contact Resistance Max. Insulation Resistance Min.
Dialectric Strength
0.5mA/Minute
Switch 30V 0.1A 50mΩ 100MΩ 500VAC
Switch Specification
S1 OFF
S3 Common
S2 ON
P1
P2
Primary side Secondary side
Galvanic isolation
Note: EXAMPLE ONLY - Connection to S2-S3 and S1-S3
depends on customer indication circuit and can vary.
R
LED
* LED is off when the product is normal (S2,S3 connected),
LED is on when the product disconect opens (switch change
status; S1,S3 connected as shown by dotted line ).
Thermal
Disconnect
MOV
S1 OFF
(Normal Open)
S3 Common
S2 ON
(Normal close)
P1
P2
Primary side Secondary side
Galvanic isolation
P1 P2
To Protected Circuit
S2
S1
P1
P2
Primary side Secondary side
Galvanic isolation
R
LED
* LED is off when the product is normal
LED is on when the product disconect opens
To Protected Circuit
LF9
TCMOV34S321MP
1208
S2
S1
P1
P2
Primary side Secondary side
Galvanic isolation
P1 P2
LF9
TCMOV34S321TP
1243
S2 S1
S3
S2 S1
Thermal
Disconnect
MOV
MP Device Lead Configuration TP Device Lead Cofiguration
MP Device Application Example TP Device Application Example
Thermal
Disconnect
MOV
Thermal
Disconnect
MOV