Features
■ 72 V rated
■ Radial leaded devices
■ Cured, fl ame retardant epoxy polymer
insulating material meets UL 94V-0
requirements
■ RoHS compliant*
■ Agency recognition:
Applications
Almost anywhere there is a low voltage power
supply, up to 72 V and a load to be protected,
including:
■ Security and fi re alarm systems
■ Loudspeakers
■ Power transformers
MF-RX/72 Series - PTC Resettable Fuses
*RoHS Directive 2002/95/EC Jan 27 2003 including Annex.
Specifi cations are subject to change without notice.
Customers should verify actual device performance in their specifi c applications.
Electrical Characteristics
Model V max.
Volts
I max.
Amps
Ihold Itrip Initial
Resistance
1 Hour (R1)
Post-Trip
Resistance
Max. Time
To Tr i p
Tripped
Power
Dissipation
Amperes
at 23 °C
Ohms
at 23 °C
Ohms
at 23 °C
Amperes
at 23 °C
Seconds
at 23 °C
Watts
at 23 °C
Hold Trip Min. Max. Max. Typ.
MF-RX020/72 72 40 0.20 0.40 1.50 2.84 4.40 1.0 2.2 0.40
MF-RX025/72 72 40 0.25 0.50 1.00 1.95 3.00 1.25 2.5 0.45
MF-RX030/72 72 40 0.30 0.60 0.76 1.36 2.10 1.5 3.0 0.50
MF-RX040/72 72 40 0.40 0.80 0.52 0.86 1.29 2.0 3.9 0.55
MF-RX050/72 72 40 0.50 1.00 0.41 0.77 1.17 2.5 4.0 0.75
MF-RX065/72 72 40 0.65 1.30 0.27 0.48 0.72 3.25 5.3 0.90
MF-RX075/72 72 40 0.75 1.50 0.18 0.40 0.60 3.75 6.3 0.90
MF-RX090/72 72 40 0.90 1.80 0.14 0.31 0.47 4.5 7.2 1.00
MF-RX110/72 72 40 1.10 2.20 0.15 0.25 0.38 5.5 8.2 1.50
MF-RX135/72 72 40 1.35 2.70 0.12 0.19 0.30 6.75 9.6 1.70
MF-RX160/72 72 40 1.60 3.20 0.09 0.14 0.22 8.0 11.4 1.90
MF-RX185/72 72 40 1.85 3.70 0.08 0.12 0.19 9.25 12.6 2.10
MF-RX250/72 72 40 2.50 5.00 0.05 0.08 0.13 12.5 15.6 2.50
MF-RX300/72 72 40 3.00 6.00 0.04 0.06 0.10 15.0 19.8 2.80
MF-RX375/72 72 40 3.75 7.50 0.03 0.05 0.08 18.75 24.0 3.20
Environmental Characteristics
Operating/Storage Temperature ........................... -40 °C to +85 °C
Maximum Device Surface Temperature
in Tripped State .................................................. 125 °C
Passive Aging ....................................................... +85 °C, 1000 hours ............................................... ±5 % typical resistance change
Humidity Aging ..................................................... +85 °C, 85 % R.H. 1000 hours ............................. ±5 % typical resistance change
Thermal Shock ..................................................... +85 °C to -55 °C, 10 times ................................... ±10 % typical resistance change
Solvent Resistance ............................................... MIL-STD-202, Method 215 ................................... No change
Vibration ............................................................... MIL-STD-883C, Method 2007.1, .......................... No change
Condition A
Test Procedures And Requirements For Model MF-RX/72 Series
Test Test Conditions Accept/Reject Criteria
Visual/Mech. ......................................................... Verify dimensions and materials ........................... Per MF physical description
Resistance ............................................................ In still air @ 23 °C .................................................. Rmin ≤ R ≤ Rmax
Time to Trip ........................................................... 5 times Ihold, Vmax, 23 °C ................................... T ≤ max. time to trip (seconds)
Hold Current ......................................................... 30 min. at Ihold ..................................................... No trip
Trip Cycle Life ....................................................... Vmax, Imax, 100 cycles ........................................ No arcing or burning
Trip Endurance ..................................................... Vmax, 48 hours ..................................................... No arcing or burning
UL File Number .................................................... E 174545
*RoHS COMPLIANT