254M06QD150 - ITW PANCON - Product.Network

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Type Q/QRL Quencharc®Capacitor

RC Snubber Network

VOLTAGE WAVEFORM

UNSUPPRESSED

100V/div .1ms/div

SUPPRESSED

100V/div .5ms/div

CURRENT WAVEFORM

UNSUPPRESSED

100V/div .1ms/div

SUPPRESSED

100V/div .1ms/div

Q/QRL

Arc Suppressor

Snubber Network

UL/CSA version

Code

Value

µF

Voltage

VDC/VAC

Type Ohms

±10% Watt L

MAX

Typical

Part

Number

104 0.1 600 / 250 QC 22 0.5 1.08 (27.4) 0.39(9.9) 0.66 (16.7) 0.82 (20.8) 104M06QC22

104 0.1 600 / 250 QC 47 0.5 1.08 (27.4) 0.39(9.9) 0.66 (16.7) 0.82 (20.8) 104M06QC47

104 0.1 600 / 250 QC 100 0.5 1.08 (27.4) 0.39(9.9) 0.66 (16.7) 0.82 (20.8) 104M06QC100

104 0.1 600 / 250 QC 150 0.5 1.08 (27.4) 0.39(9.9) 0.66 (16.7) 0.82 (20.8) 104M06QC150

104 0.1 600 / 250 QC 220 0.5 1.08 (27.4) 0.39(9.9) 0.66 (16.7) 0.82 (20.8) 104M06QC220

104 0.1 600 / 250 QC 330 0.5 1.08 (27.4) 0.39(9.9) 0.66 (16.7) 0.82 (20.8) 104M06QC330

104 0.1 1200 / 480 QH 39 2.0 1.60(40.6) 0.64(16.3) 1.04(26.4) 1.29(32.7) 104M48QH39

104 0.1 1600 / 660 QV 39 2.0 2.18(55.3) 0.54(13.7) 1.00(25.4) 1.80(45.7) 104M66QV39

254 0.25 600 / 250 QD 22 0.5 1.45(36.8) 0.42(10.6) 0.75(19.0) 1.20(30.5) 254M06QD22

254 0.25 600 / 250 QD 47 0.5 1.45(36.8) 0.42(10.6) 0.75(19.0) 1.20(30.5) 254M06QD47

254 0.25 600 / 250 QD 100 0.5 1.45(36.8) 0.42(10.6) 0.75(19.0) 1.20(30.5) 254M06QD100

254 0.25 600 / 250 QD 150 0.5 1.45(36.8) 0.42(10.6) 0.75(19.0) 1.20(30.5) 254M06QD150

504 0.5 600 / 250 QE 22 0.5 1.45(36.8) 0.59(15.0) 0.92(23.4) 1.20(30.5) 504M06QE22

504 0.5 600 / 250 QE 47 0.5 1.45(36.8) 0.59(15.0) 0.92(23.4) 1.20(30.5) 504M06QE47

504 0.5 600 / 250 QE 100 0.5 1.45(36.8) 0.59(15.0) 0.92(23.4) 1.20(30.5) 504M06QE100

504 0.5 600 / 250 QE 150 0.5 1.45(36.8) 0.59(15.0) 0.92(23.4) 1.20(30.5) 504M06QE150

504 0.5 200 / 125 QA 22 0.5 1.08(27.4) 0.37(9.4) 0.64(16.3) 0.82(20.8) 504M02QA22

504 0.5 200 / 125 QA 47 0.5 1.08(27.4) 0.37(9.4) 0.64(16.3) 0.82(20.8) 504M02QA47

504 0.5 200 / 125 QA 100 0.5 1.08(27.4) 0.37(9.4) 0.64(16.3) 0.82(20.8) 504M02QA100

504 0.5 200 / 125 QA 220 0.5 1.08(27.4) 0.37(9.4) 0.64(16.3) 0.82(20.8) 504M02QA220

105 1.0 200 / 125 QB 22 0.5 1.45(36.8) 0.39(9.9) 0.66(16.7) 1.20(30.5) 105M02QB22

105 1.0 200 / 125 QB 47 0.5 1.45(36.8) 0.39(9.9) 0.66(16.7) 1.20(30.5) 105M02QB47

UL/CSA Recognized Across-the-Line Application Note: Complies with UL1414 / CSA-C22.2 No.1

104 0.1 125 VAC QRL 150 0.5 1.08(27.4) 0.44(11.18) 0.66(16.7) 0.82(20.8) 104MACQRL150

104 0.1 125 VAC QRL 680 0.5 1.08(27.4) 0.44(11.18) 0.66(16.7) 0.82(20.8) 104MACQRL680

Type QRL: UL Recognized for 125 VAC across-the-line. UL File No. E33628

CSA Certified for 125 VAC across-the-line. CSA File No. LR32208

Dimensions in inches, metric (mm) in parenthesis.

Non-polarized

Electrical

Schematic

Energy Efficient Noise Suppression

• Relay contact protection • Noise reduction on controllers/drivers

• dv/dt suppression on thyristor and triacs • EMI/RFI reduction

• No lag time in suppression • Available voltages: 125 VAC - 660 VAC

• Type QRL – UL/CSA version • RoHS-6 Compliant

www.paktron.com PAGE 19

Type Q/QRL Quencharc®Capacitor

RC Snubber Network

The most popular and commonly used method of arc

suppression is to connect a resistor-capacitor network

as shown in Figures A and B. The preferred method of

connection is across the contacts it wants to protect.

However, the network can be hooked across the load,

as is shown by the dashed line, when all inductance of

the load circuit is considered lumped together.

When the contacts open, the voltage across the

uncharged capacitor is zero and the transient voltage

starts charging the capacitor. In the meantime, the gap

of the contact is steadily widened, and by the time the

capacitor is charged to its full potential, the contact

gap is widened well beyond the minimum breakdown

potential of air, thus preventing the arcing. When the

contact closes, the inrush current from the capacitor

may damage the contact, and here resistance is

needed to limit the maximum current to Eo/Rc during

the contact closure.

The induced voltage on opening the contact is:

and, as can be seen, the larger the value of a series

resistor, the higher the induced voltage.

On the other

hand, the lower series resistance makes the current

on contact closure higher. The time dependence of

the voltage is given by:

and the rate of voltage change, which is important in

transient suppression of triac switching, is:

Equation 3 tells us that by knowing the circuit

conditions with given values of L and coil resistance

that limit the current prior to contact opening, the

rate of voltage rise is inversely proportional to

capacitance. In other words, the larger the

capacitance, the greater is the transient suppression.

However, when the contact closes, the additional

energy stored in the capacitor has to be discharged

through the contact. Hence, a compromise has to be

made in the selection of both resistance and

capacitance.

In an effort to provide a simple answer to designers’

requests for proper values of resistance and

capacitance, some relay manufacturers came out

with empirical formulas and nomographs. For

instance, C.C. Bates1 gives the equations:

where

C = capacitance in µ

I = load current in amperes prior to contact opening

R = resistance in ohms in series with capacitor

Eo = source voltage

The choice of resistance and capacitance value

however, is quite flexible. In fact, the choice is so

simple that one does not need a nomograph at all.

Besides, a nomograph published by a certain relay

manufacturer may be for the particular relays the firm

manufactures, not necessarily universal.

1Bates, C.C., “Contact Protection of Electro-

magnetic Relays.” Electro-mechanical Design,

August, 1966.

Eo

C

L RL

RC

Eo

C

L R

L

C

Figure A Figure B

HOW QUENCHARC® WORKS

OPERATING

TEMPERATURE RANGE –55°C to

+85°C at full rated voltage.

DISSIPATION FACTOR

The nominal dissipation factor is

determined from the

following equation:

DF = 2fCR + 0.006

where:

f = test frequency in hertz

C= nominal capacitance value in

farads

R = nominal value of series resistor

in Ω.

DIELECTRIC WITHSTANDING

VOLTAGE

Unit shall withstand a DC poten-

tial of 1.6 times the DC voltage

rating. Testing conducted at 25°C.

DC LIFE TEST

Unit shall withstand a test potential

of 125% of the rated voltage for a

period of 500 hours at a tempera-

ture of

85°C. A failure shall consist of:

• Capacitance change greater than 5%.

• Dissipation factor greater than origi-

nal limits.

LONG TERM STABILITY

The capacitance shall not change

more than 2% when stored at

ambient temperature and humidity

for a period of 2 years or less.

PHYSICAL

TOLERANCE

Capacitor ± 20%, Resistor

± 10%.

CONSTRUCTION*

Metallized polyester

capacitor in series with a carbon

composition resistor.

CASE

Coated with a UL94V-0 flame

retardant epoxy.

WIRE LEADS

#20 AWG (0.032") capacitor end.

Resistor end 0.025" to 0.032".

MARKING

, Quencharc®,

capacitance, resistance, voltage.

* 39Ω resistors are power wire-

wound

CHOOSING A QUENCHARC®

In choosing a Quencharc®, first of all, check the maximum switching current rating of the contacts to be

protected. This value differs for different types of contact materials and different types of relays. The maxi-

mum current during the contact closure with an RC network is Eo/Rc, where Eo is the source voltage and Rc is

the resistance value of the network. The quantity Eo/Rc must be lower than the maximum switching current

for obvious reasons. Next, the selection of capacitance is best done with an oscilloscope.

Connect the oscilloscope probe to the relay wiper and ground the other plate of the contact. Without an RC

network across the contacts, check the amplitude of the transient voltage on contact break and the ampli-

tude of the current on contact make. If the voltage is less than 300V and the current less than the maximum

switching current rating of the relay, and if you don’t see any arcing, you may not need the contact protection

at all. If you spot arcing, connect a 0.1 µF + 100, 250 VAC, QC100 (our most widely used Quencharc®), across

the contacts, and observe the levels of suppression, voltage on break and current on make. The suppressed

voltage should be below 250V, which provides 70 volts of safety margin from the breakdown potential of air.

If the voltage is still above 250V, try a 0.25 µF + 220 or a 0.5 µF + 330 range. If you need a higher capaci-

tance than 1.0 µF, you may be better off with a Zener or a varistor in terms of cost and space. For most relays

and triacs 0.1 µF + 100 provides a satisfactory suppression.

When protecting contacts in AC circuits, the same general guidelines as for DC circuits can be used, but the

wattage of the resistor must be considered if current flow is sustained for a long enough period of time to

heat the component. Compute the impedance of the RC unit to obtain a current value, then use I2R and time

considerations to determine whether the standard network resistor is adequate.

V = IRC = RC Eo

dv = L di + (RL + RC) di + i

dt dt dt C

V(t) = L di + (RL +RC)i + Eo + 1

t idt

dt C °

(1)

(2)

(4)

(3)

C = I2 R = Eo

10 10I(1+ 50 )