Pulse Withstanding Fusible Flameproof Metal Film Resistors EMC Series

The EMC Series resistors are designed for applications requiring reliable fusing and flameproof protection, particularly in 240V mains environments. They offer good pulse handling capabilities and a compact size relative to their power rating, making them suitable for surface-mount applications. The UL1412 recognition and UL94-V0 flameproof rating ensure safety and compliance.

Product Attributes

• Brand: TT Electronics (BI Technologies, IRC, Welwyn)
• Certifications: UL1412 recognised (values 22R and above), UL file number E234469, UL94-V0 flameproof protection, RoHS3 compliant
• Material: Metal film deposited on a high purity ceramic rod, solder-coated copper wire terminations
• Construction: Force-fitted end caps, welded termination wires, cement protection
• Color: Indelible ink marking, color coded with five bands (four for value/tolerance, fifth yellow for fusibility)
• Origin: Not specified

Technical Specifications

Performance Data

Pulse Performance

Graphs for Single Rectangular Pulse and IEC61000-4-5 1.2/50s Pulse are provided in the original document, illustrating Pk Power vs Pulse Duration and Pk Voltage vs Value respectively. Specific data points are not extracted here.

Fusing Performance

EMC resistors fuse open circuit at overload powers exceeding 60W within the time indicated on the Fusing Characteristic. Their fusing performance at lower overload powers is not specified. EMC resistors fuse safely in the event of a 115Vrms / 240Vrms overload (line / mains short circuit condition) without burning or emitting incandescent particles. After fusing, the resistance is at least 100 times greater than the original nominal value.

Fusing Characteristic (Constant Voltage)

Initial Power (W) | Max. Fusing Time (s)

40 | 0 (4R7-8R2)

50 | 5 (4R7-8R2) / 10 (10R-68R)

60 | 10 (4R7-8R2) / 15 (10R-68R)

70 | 20 (10R-68R)

80 | 20 (10R-68R)

90 | 20 (10R-68R)

100 | 20 (10R-68R)

Flammability

The resistor coating is UL94-V0 rated and will not burn or emit incandescent particles under any condition of applied temperature or power overload.

Marking

EMC resistors are colour coded with five bands. Four of the bands indicate value and tolerance in accordance with IEC62. Parts with 20% tolerance have no fourth band. A fifth yellow band denotes constant voltage fusibility.

Shelf Life

12 months at room temperature (R% 2)

Climatic

Category 50/155/56 (R% 3)

Temperature rapid change

(R% 0.5)

Resistance to solder heat

(R% 0.5)

Maximum Load at Rated Power

1000hrs @ 70C (R% 1)

Application Notes

• Terminations should not be soldered closer than 4mm from the body for full rated power dissipation.
• Derating may be necessary due to operating temperature limits imposed by some PCB materials.
• A positive clearance of at least 13mm should be provided between the resistor body and any combustible materials to protect against fire under all conditions of overload.
• EMC resistors can be supplied with radial, goalpost or lancet pre-formed leads, or in ZI-form SMD format packed in blister tape.

Packaging

Standard packaging is taped and boxed. Alternative packaging is available by request.

Ordering Procedure Example

EMC2-33RMI (EMC2, 33 ohms 20%, Pb-free)

• EMC2: Type
• 33R: Value
• M: Tolerance (M = 20%)
• I: Packing (I = Ammo 2000/box)

Other options include:

• Leadforming: Blank = Axial, R = Radial taped
• Tolerance: K = 10%
• Packing: R = Reel 1500/reel, T15 = Tape 1500/reel

General Note: TT Electronics reserves the right to make changes in product specification without notice or liability. All information is subject to TT Electronics own data and is considered accurate at time of going to print.