® Type Q/QRL Quencharc Capacitor RC Snubber Network • Relay contact protection • Noise reduction on controllers/drivers Arc Suppressor Snubber Network • 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 L Max. T Max. ® ¤ Quencharc ITW PAKTRON Q/QRL Arc Suppressor ¤ QUENCHARC Snubber Network ITW PAKTRON H Max. ¤ QUENCHARC UL/CSA version .25" Max. .850" Min. ARCING, SPARKING, and TRANSIENTS often cause premature failures in relays, switches, thyristors, triacs, contactors, and related products. Paktron ¤ QUENCHARCS extend operating life when properly selected and applied. D Typ. VoLTAgE WAVEFoRM CURRENT WAVEFoRM Electrical Schematic Non-polarized UNSUPPRESSED SUPPRESSED UNSUPPRESSED SUPPRESSED 100V/div .1ms/div 100V/div .5ms/div 100V/div .1ms/div 100V/div .1ms/div PF Value Voltage Type Ohms Watt L T H D Part VDC/VAC MAX MAX MAX Typical Code µF ±10% Number 104 .1 600 / 250 QC 22 .5 1.08 (27.4) .39(9.9) .66 (16.7) .82 (20.8) 104M06QC22 104 .1 600 / 250 QC 47 .5 1.08 (27.4) .39(9.9) .66 (16.7) .82 (20.8) 104M06QC47 104 .1 600 / 250 QC 100 .5 1.08 (27.4) .39(9.9) .66 (16.7) .82 (20.8) 104M06QC100 104 .1 600 / 250 QC 150 .5 1.08 (27.4) .39(9.9) .66 (16.7) .82 (20.8) 104M06QC150 104 .1 600 / 250 QC 220 .5 1.08 (27.4) .39(9.9) .66 (16.7) .82 (20.8) 104M06QC220 104 .1 600 / 250 QC 330 .5 1.08 (27.4) .39(9.9) .66 (16.7) .82 (20.8) 104M06QC330 104 .1 1200/480 QH 39 2.0 1.60(40.6) .64(16.3) 1.04(26.4) 1.29(32.7) 104M48QH39 104 .1 1600/660 QV 39 2.0 2.18(55.3) .54(13.7) 1.00(25.4) 1.80(45.7) 104M66QV39 254 .25 600 / 250 QD 22 .5 1.45(36.8) .42(10.6) .75(19.0) 1.20(30.5) 254M06QD22 254 .25 600 / 250 QD 47 .5 1.45(36.8) .42(10.6) .75(19.0) 1.20(30.5) 254M06QD47 254 .25 600 / 250 QD 100 .5 1.45(36.8) .42(10.6) .75(19.0) 1.20(30.5) 254M06QD100 254 .25 600 / 250 QD 150 .5 1.45(36.8) .42(10.6) .75(19.0) 1.20(30.5) 254M06QD150 504 .5 600 / 250 QE 22 .5 1.45(36.8) .59(15.0) .92(23.4) 1.20(30.5) 504M06QE22 504 .5 600 / 250 QE 47 .5 1.45(36.8) .59(15.0) .92(23.4) 1.20(30.5) 504M06QE47 504 .5 600 / 250 QE 100 .5 1.45(36.8) .59(15.0) .92(23.4) 1.20(30.5) 504M06QE100 504 .5 600 / 250 QE 150 .5 1.45(36.8) .59(15.0) .92(23.4) 1.20(30.5) 504M06QE150 504 .5 200 / 125 QA 22 .5 1.08(27.4) .37(9.4) .64(16.3) .82(20.8) 504M02QA22 504 .5 200 / 125 QA 47 .5 1.08(27.4) .37(9.4) .64(16.3) .82(20.8) 504M02QA47 504 .5 200 / 125 QA 100 .5 1.08(27.4) .37(9.4) .64(16.3) .82(20.8) 504M02QA100 504 .5 200 / 125 QA 220 .5 1.08(27.4) .37(9.4) .64(16.3) .82(20.8) 504M02QA220 105 1.0 200 / 125 QB 22 .5 1.45(36.8) .39(9.9) .66(16.7) 1.20(30.5) 105M02QB22 105 1.0 200 / 125 QB 47 .5 1.45(36.8) .39(9.9) .66(16.7) 1.20(30.5) 105M02QB47 Dimensions in inches, metric (mm) in parenthesis. RoHS-6 Compliant UL/CSA Recognized Across-the-Line Application Note: Complies with UL1414 / CSA-C22.2 No.1 104 .1 125 VAC QRL 150 .5 1.08(27.4) .44(11.18) .66(16.7) .82(20.8) 104MACQRL150 104 .1 125 VAC QRL 680 .5 1.08(27.4) .44(11.18) .66(16.7) .82(20.8) 104MACQRL680 RoHS-6 Compliant 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 PAGE 18 • ITW Paktron • P.O. Box 4539, 1205 McConville Road, Lynchburg, Virginia 24502 • Tel 434-239-6941 • Fax 434-239-4730 • www.paktron.com ® Type Q/QRL Quencharc Capacitor RC Snubber Network ® oPERATINg HOW QUENCHARC WORKS TEMPERATURE RANGE –55°C to +85°C at full rated The most popular and commonly used method of voltage. arc suppression is to connect a resistor-capacitor and the rate of voltage change, which is important network as shown in Figures A and B. The in transient suppression of triac switching, is: DISSIPATION FACTOR preferred method of connection is across the 2 dv d i di i The nominal dissipation factor = L + (RL + RC) + contacts it wants to protect. However, the network 2 dt dt dt C is determined from the can be hooked across the load, as is shown by the following equation: dashed line, when all inductance of the load circuit Equation (3) tells us that by knowing the circuit DF = 2fCR + .006 is considered lumped together. conditions with given values of L and coil resistance where: that limit the current prior to contact opening, the f = test frequency in hertz rate of voltage rise is inversely proportional to Eo Eo C = nominal capacitance capacitance. In other words, the larger the L RL value in farads L RL capacitance, the greater is the transient R = nominal value of series suppression. However, when the contact closes, C RC resistor in ohms. the additional energy stored in the capacitor has to C RC be discharged through the contact. Hence, a DIELECTRIC WITHSTANDING Figure A compromise has to be made in the selection of Figure B VOLTAGE both resistance and capacitance. Unit shall withstand a DC In an effort to provide a simple answer to When the contacts potential of 1.6 times the DC designers’ requests for proper values of resistance open, the voltage across the uncharged capacitor is voltage rating. Testing con- and capacitance, some relay manufacturers came zero and the transient voltage starts charging the out with empirical formulas and nomographs. For ducted at 25°C. capacitor. In the meantime, the gap of the contact is 1 instance, C.C. Bates gives the equations DC LIFE TEST steadily widened, and by the time the capacitor is Unit shall withstand a test charged to its full potential, the contact gap is potential of 125% of the rated widened well beyond the minimum breakdown 2 I E o voltage for a period of 500 C = R = potential of air, thus preventing the arcing. When the 50 10 10I(1+ ) hours at a temperature of E contact closes, the inrush current from the capacitor o 85°C. A failure shall consist of: may damage the contact, and here resistance is where • Capacitance change greater needed to limit the maximum current to Eo/Rc C = capacitance in mF during the contact closure. than 5%. I = load current in amperes prior to contact The induced voltage on opening the • Dissipation factor greater than opening contact is R = resistance in ohms in series with capacitor original limits. RC E = source voltage o V = IRC = E (1) o LONG TERM STABILITY RL The choice of resistance and capacitance value The capacitance shall not however, is quite flexible. In fact, the choice is so and, as can be seen, the larger the value of a series change more than 2% when simple that one does not need a nomograph at all. resistor, the higher the induced voltage. On the stored at ambient temperature Besides, a nomograph published by a certain relay other hand, the lower series resistance makes the manufacturer may be for the particular relays the and humidity for a period of 2 current on contact closure higher. The time firm manufactures, not necessarily universal. years or less. dependence of the voltage is given by: 1 Bates, C.C., “Contact Protection of PhySICAL t di 1 V(t) = L + (RL +RC)i + Eo + idt Electromagnetic Relays.” Electro-mechanical * C ° dt Design, August, 1966. TOLERANCE Capacitor ± 20%, Resistor contact protection at all. If you spot arcing, ® ± 10%. CHOOSING A QUENCHARC connect a .1 mF + 100 ohm, 250 VAC, QC100 ® In choosing a Quencharc , first of all, check ® CONSTRUCTION* (our most widely used Quencharc ), across the maximum switching current rating of the Metallized polyester the contacts, and observe the levels of contacts to be protected. This value differs for suppression, voltage on break and current on capacitor in series with a make. The suppressed voltage should be different types of contact materials and carbon composition resistor. below 250V, which provides 70 volts of safety different types of relays. The maximum CASE margin from the breakdown potential of air. If current during the contact closure with an RC Coated with a UL94V-0 the voltage is still above 250V, try a .25 mF + network is E /R , where E is the source o c o flame retardant epoxy. 220 ohms or a .5 mF + 330 ohms range. If you voltage and R is the resistance value of the c WIRE LEADS need a higher capacitance than 1.0 mF, you network. The quantity E /R must be lower o c #20 AWG (.032") capacitor may be better off with a Zener or a varistor in than the maximum switching current for terms of cost and space. For most relays and end. #18 AWG (.040") for obvious reasons. Next, the selection of triacs .1 mF + 100 ohms provides a satisfactory QH & QV styles. Resistor capacitance is best done with an oscilloscope. suppression. end .025" to 0.045". Connect the oscilloscope probe to the relay When protecting contacts in AC circuits, the MARkING wiper and ground the other plate of the contact. same general guidelines as for DC circuits can ® ITW, Quencharc , Without an RC network across the contacts, be used, but the wattage of the resistor must capacitance, resistance, check the amplitude of the transient voltage on be considered if current flow is sustained for a contact break and the amplitude of the current voltage. long enough period of time to heat the on contact make. If the voltage is less than component. Compute the impedance of the 300V and the current less than the maximum 2 * 39 ohm resistors are power RC unit to obtain a current value, then use I R switching current rating of the relay, and if you wire-wound and time considerations to determine whether don’t see any arcing, you may not need the the standard network resistor is adequate. ITW Paktron • P.O. Box 4539, 1205 McConville Road, Lynchburg, Virginia 24502 • Tel 434-239-6941 • Fax 434-239-4730 • www.paktron.com • PAGE 19