Pulse Withstanding Fusible

Flameproof Metal Film Resistors

EMC Series

Application Notes

1.Iftheresistorsaretodissipatefullratedpower,itisrecommendedthattheterminationsshouldnotbesolderedcloserthan4mm

from the body.

2.DuetooperatingtemperaturelimitsimposedbysomePCBmaterials,deratingmaybenecessary.Anestimateofthetemperaturerise

tobeexpectedcanbecalculatedusingthethermalimpedancefiguresgivenunderElectricalData.

3.Toprotectagainstfireunderallconditionsofoverload,apositiveclearanceofatleast13mmshouldbeprovidedbetweenthebodyof

theresistorandanycombustiblematerials.

4.EMCresistorscanalsobesuppliedloosepackedwithradial,goalpostorlancetpre-formedleads,tapepackedwithradialpre-formed

leads,orinZI-formSMDformatpackedinblistertape-seehttp://www.ttelectronics.com/themes/ttelectronics/datasheets/resistors/

ZI-form.pdf

Packaging

OurstandardpackagingforEMCistapedandboxed.ThecriticaldimensionsareshowninFigure1.Thecomponentwireswillnot

protrudebeyondtheoutsideedgeofthetapes.Alternativepackagingisavailablebyrequest.

mm

EMC2

b

68

b

6

6

5

Figure 1

03.17

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.

© TT Electronics plc

http://www.ttelectronics.com/resistors

BI Technologies IRC Welwyn

EMC2RRadialTapedDimensions(mm)

Dimension

Notation Nominal

Tolerance

Component Body Length

L

10.0 Max

Component Body Diameter

D

4.0 Max

Terminal Lead Diameter

d

0.8 Nom

Component Pitch

P

12.7

±0.5

PitchofHoles

Po

12.7

±0.2

DistancebetweenHole&Component

P1

3.85

±0.3

P2

5.85

±0.5

Lead Pitch

F

5.0

+0.75-0.34

WidthofBackingStrip

W

18.0

±0.3

PositionofHole

W1

9.0

±0.25

DiameterofHole

Do

4.0

±0.3

HeighttoLeadForm

Ho

16.0

±0.3

HeightfromLeadForm

Ho1

21.7 Max

HeighttoResistor

Ho2

18.0 Max

Width of Adhesive Tape

W2

15.0

±0.5

Length of protrusion

l

<2.5

Form Dimensions

K1

2.0

±0.3

K2

3.0

±0.5

K3

1.5

±0.25

K4

1.0

±0.2

Also a 2W radial taped version is available as shown below

Application Notes

Application Notes

1. If the resistors are to dissipate full rated power, it is recommended that the terminations should not be soldered closer than

4mm from the body.

2. Due to operating temperature limits imposed by some PCB materials, derating may be necessary. An estimate of the

temperature rise to be expected at the center of the body can be calculated using the thermal impedance figures given under

Electrical Data.

3. For the purpose of UL approval, the following points should be observed:

3.1 To protect against fire under all conditions of overload, a positive clearance of at least 13mm should be provided

between the body of the resistor and any combustible materials.

3.2 A positive clearance of 13mm should be provided between the resistor body or terminations and uninsulated parts of

opposite polarity or uninsulated dead metal parts.

3.3 Limited Short Circuit testing should be performed in the complete appliance.

4. ULW resistors can also be supplied with radial, goalpost or lancet pre-formed leads. In particular ULW2, ULW3, ULW4 and

ULW5 are available in ZI-form SMD format packed in blister tape – see

http://www.ttelectronics.com/sites/default/files/resistors-datasheets/ZI-form.pdf

Also a 2W radial taped version* is available as shown below.

*Although body dimensions differ slightly, ULWP2R Performance and Electrical Data are identical to those of ULW2

ULWP2R Radial Taped Dimensions (mm)

Dimension

Notation Nominal

Tolerance

Component Body Length

L

10.0 Max

Component Body Diameter

D

4.0 Max

Terminal Lead Diameter

d

0.8 Nom

Component Pitch

P

5

±0.5

Pitch of Holes

Po

10

±0.2

Distance between Hole &

Component

P1

3.85

±0.3

P2

5.85

±0.5

Lead Pitch

F

5.0

+0.75 -0.34

Width of Backing Strip

W

18.0

±0.3

Position of Hole

W1

9.0

±0.25

Diameter of Hole

Do

4.0

±0.3

Height to Lead Form

Ho

16.0

±0.3

Height from Lead Form

Ho1

17.0 MAX

Height to Resistor

Ho2

18.0 MIN

Width of Adhesive Tape

W2

15.0

±0.5

Length of protrusion

l

<2.5

Form Dimensions

K1

2.0

±0.3

K2

3.0

±0.5

K3

1.5

±0.25

K4

1.0

±0.2

(Delete redundant subtitle)

(This diagram exists on WP-S,

so just copy it)