SERIES H,HD,HP,HT,HTD,HPT ENGINEERING DATA SHEET CONTACTOR 60 AMP Balanced-Force Design Hermetically sealed Designed to the performance standards of MIL-PRF-6106 PRINCIPLE TECHNICAL CHARACTERISTICS Contacts rated at 28 Vdc and 115 Vac,400 Hz, 1 Ø and 115/200 Vac 400Hz, 3 Ø Weight 400 g Special units available upon request, including models with auxiliary contacts. Optional Ground Fault Protection (GEP) Feature Available. APPLICATION NOTES: 101 102 104 105 007 Contact factory for information on MIL-qualified part numbers. CONTACT ELECTRICAL CHARACTERISTICS Contact rating per pole and load type [1] Resistive Inductive [2] Motor Intermediate current Load transfer [3] Load current in Amps 28 Vdc 50 20 20 10 - 50 [5] 20 [5] - Featuring LEACH© power and control solutions www.esterline.com 115 Vac 400 Hz 60 60 12.5/60 AMERICAS 6900 Orangethorpe Ave. P.O. Box 5032 Buena Park, CA 90622 . . Tel: (01) 714-736-7599 Fax: (01) 714-670-1145 115/200 Vac 400 Hz 3Ø 115 Vac 60 Hz DELTA 60 60 40 15 12.5/60 30 30 30 - 65 [5] 65 [5] 12.5/60 EUROPE 2 Rue Goethe 57430 Sarralbe France . . Tel: (33) 3 87 97 31 01 Fax: (33) 3 87 97 96 86 ASIA Units 602-603 6/F Lakeside 1 No.8 Science Park West Avenue Phase Two, Hong Kong Science Park Pak Shek Kok, Tai Po, N.T. Hong Kong Tel: (852) 2 191 3830 Fax: (852) 2 389 5803 Data sheets are for initial product selection and comparison. Contact Esterline Power Systems prior to choosing a component. Date of issue: 01/11 - 60 - Page 1 of 5 COIL CHARACTERISTICS (Vdc) SERIES H,HD,HP,HT,HTD,HPT CODE A Vdc B Vdc C Vdc F Vac 400Hz N [6] Vdc Nominal operating voltage 28 12 6 115 28 Maximum operating voltage 29 14.5 7.3 124 29 - Nominal 18 9 4.5 90 18 - High temp test 20 10 5 95 20 - Continuous current test 22.5 11 5.7 100 22.5 Drop-out voltage, maximum 7 4.5 2.5 30 7 Coil resistance in Ohms ±10% at +25° C 200 50 12 - 200 Coil current max. mA at +25° C - - - 90 - Pick-up voltage, maximum GENERAL CHARACTERISTICS Temperature range -55°C to +71°C Minimum operating cycles (life) at rated resistive load 50,000 Minimum operating cycles (life) at 25% rated resistive load 200,000 Dielectric strength at sea level - All circuits to ground and circuit to circuit 1500 Vrms - Coil to ground and aux. contacts 1000 Vrms Dielectric strength at altitude: 15,240 m - Main contacts 700 Vrms - Coil and aux. contacts 500 Vrms Insulation resistance - Initial 100 M Ω min - After environmental tests 50 M Ω min Sinusoidal vibration 10 G / 70 to 2000 Hz Shock (6 ms duration) 50 G Maximum contact opening time under vibration and shock 10 µs Operate time at nominal voltage (Including bounce) 50 ms max 35 ms max. [5] Release time at nominal voltage (Including bounce) - DC 25 ms max - AC 80 ms max Contact bounce at nominal voltage 3 ms max Weight 400 grams max. 330 grams max. [5] Power requirements: - at pick-up +25° C 0.980 watt - at nominal D.C. voltage 4.35 watt max. Overload @ 115/200 Vac, 400Hz. @ 28 Vdc 400 Amp 125 Amp Rupture @ 115/200 Vac, 400Hz. @ 28 Vdc 500 Amp 150 Amp Date of issue: 01/11 - 61 - Page 2 of 5 NUMBERING SYSTEM SERIES H,HD,HP,HT,HTD,HPT H - X 0 X [7] HD - X 0 X [8] HP - X 0 X [4] HT - X 0 X [7]HTD - X 0 X [8]HTP - X 0 X Relay family_____________________________________| | | | 1-Mounting Style(A,B,Etc.)____________________________| | | 2-Terminal & Circuit (1,2,3,Etc.)_________________________| | 3-Coil Voltage(A,B,C,F & N)___________________________________| NOTES [1] Auxiliary contact rating - see page 5, note [2]. [2] Inductive load life, 20,000 cycles. [3] Applicable military specification: MS27751, MIL-6106/26, MIL-PRF-6106/43. [4] Suitable for transfer between unsyncronized A.C. power sources at the ratings indicated: 12.5 amperes for series "H, HD, HP"; (MS27751-1,-7,-8,-9,-10 & -15). 60 Amperes for series "HT, HTD, HTP"; (MS27751-11,-12,17,-18,-19 & -20). [5] Terminal type 6, 8, & 10. [6] Suppressed "N" coil has back EMF suppression to 42 volts max. Consult factory. [7] Non-hermetic, gasket sealed version. [8] Non-hermetic, non-metallic cover gasket sealed version. (Not available with mounting style C). Date of issue: 01/11 - 62 - Page 3 of 5 CONFIGURATION STYLES SERIES H,HD,HP,HT,HTD,HPT STANDARD TOLERANCE: XX ± .76, XXX ± .25mm Date of issue: 01/11 - 63 - Page 4 of 5 TERMINAL CONFIGURATION AND CIRCUIT DIAGRAMS TERMINAL TYPE 1 TERMINAL TYPE 2 3 PDT 3 PST - N.O. C3 C2 C2 C1 C1 B2 B3 B1 B2 A2 B1 +X1 -X2 C1 C1 A2 A1 12 B3 B3 B2 B2 B1 B1 11 A3 A3 23 A2 A2 22 1 C2 C2 B1 -X2 C3 C3 B2 + 23 11 C1 1 A1 A1 + +X1 -X2 -X2 1 1 2 1 TERMINAL TYPE 7 3 PDT WITH SPDT AUX. MOUNTING STYLE "C" ONLY SPST - N.O. DM WITH SPST - N.O. SPST - N.C. AUX. A1 A2 22 23 13 12 12 11 11 C3 A3 TERMINAL TYPE 10 IS A GENERAL CATAGORY USED FOR ALL TERMINAL TYPES NOT ILLUSTRATED FOR OTHER VARIATIONS OF TERMINAL CONFIGURATIONS PLEASE CONTACT FACTORY. SPST - N.C. DB WITH 1 PDT AUX. 11 + +X1 C1 +X1 B3 -X2 B2 -X2 1 + 1 B1 SPDT - DB/DM WITH 1PDT AUX. 13 12 11 A4 C2 12 A3 A4 A1 A2 + +X1 2 -X2 A3 2 2 2 TERMINAL TYPE 9 TERMINAL TYPE 8 13 + +X1 + +X1 -X2 TERMINAL TYPE 6 3 PDT WITH SPST - N.C. AUX. 22 C2 + +X1 3 PDT WITH SPST - N.O. AUX. 12 A3 A2 TERMINAL TYPE 5 TERMINAL TYPE 4 TERMINAL TYPE 3 3 PST - N.O. WITH SPST - N.O. & SPST - N.C. AUXILIARY CONTACTS A1 A1 SERIES H,HD,HP,HT,HTD,HPT 1 2 A2 A1 + +X1 -X2 1 2 3.17 MAX 3.17 MAX +X1 + -X2 TERMINAL TYPE 1, 4, 5 STANDARD COIL "A","B","C","F" TERMINAL TYPE 7 + +X1 -X2 SUPPRESSED COIL "N" 1 POLARITY INDICATION APPLIES TO D.C. COILS ONLY 2 AUXILIARY CONTACT RATING: 28 VDC OR 115 VAC 2.50 MAX RESISTIVE 5 AMP INDUCTIVE 3 AMP LAMP 1 AMP CONTACT BOUNCE AT NOMINAL VOLTAGE (SECONDS) .004 MAX NOTE: OTHER AUXILIARY CONTACT FORMS ARE AVAILABLE. PLEASE CONTACT FACTORY. TERMINAL TYPE 2, 3, 6, 8, 10 NOT E : A lthough all configuration and/or terminal type options are available, some combinations may require a setup charge and be subject to minimum order size. Date of issue: 01/101 - 64 - Page 5 of 5 N°101 Application notes DERATING OF CONTACTS FOR DC VOLTAGES ABOVE NOMINAL RATING To establish a standard for the derating of relay contacts is, at best, a subjective practice. Limitations are governed by the type of relay, contact gap, maximum voltage capabilities of the relay contact system, and the contact material. The most common method is to derate the contacts by use of the Power Formula, using the known current and voltage. This method is valid only for Resistive Loads, and is an approximation only; keeping in mind the limitations mentioned above. Power = IE (Current x Voltage) I2 E2 = 2/3 I1E1 Example: A designer is working with a 55 volt DC system and has a relay rated at 10 amps resistive at 28 volts DC. What is the maximum current that can be switched at 55 Vdc. I1 = 10 Amperes E1 = 28 VDC E2 = 55 VDC I2 = ? (Current ratings at 55 VDC Resistive) I2 E2 = 2 I1 E1/3 I2 = 2 I1 E1/E23 = 2 (10 x 28)/55 x 3 = 560/165 I2 = 3.4 Amperes at 55VDC In addition, the user should always be concerned about the following: 1. Derating contacts that are rated for less than 10 Amperes at nominal voltage. 2. Derating contacts for use in system voltages above 130 Volts DC Date of issue: 6/00 - 14 - Page 1 of 1 N°102 Application notes RELAYS AND TEMPERATURE VARIATIONS Most relay parameters are specified as maximum values over the rated temperature range of the specific relay. Users often find that key parameters differ significantly at ambient temperature (20-25°C) and sometimes fall into the trap of specifying their system around these ambient parameters. Additionally the actual temperature experienced by the relay can be far in excess of existing ambient temperatures due to the heat generated by the coil current and the contact load. Figure 1 is the summary of temperature effects on relay electrical characteristics. Temperature Resistance Current Operating Voltage Release Voltage Operate Time Release Time Increase UP DOWN UP UP UP UP Decrease DOWN UP DOWN DOWN DOWN DOWN Fig. 1 The following formulas are sometimes useful in calculating the effects shown above. 1. Change in coil resistance due to change of ambient temperature can be calculated by the following formula. R = R20 [1 + .0039 (T-20)] Where: R = Coil resistance at given temperature R20 = Coil resistance at 20°C T = °C Ambient temperature "Rule of Thumb" : For each 10°C change of temperature, coil resistance will change approximately 4%. 2. High and low temperature pick up voltage: E2 = E1K2, Where: E2 = Pick Up Voltage at T2 temperature E1 = Pick Up Voltage at 20°C K2 = Coefficient of correction found on the graph in Fig. 2 at T2 Date of issue: 6/00 - 15 - Page 1 of 2 3. Calculation of coil temperature rise when R initial and R final are known: Delta T = (234.5 + T1) (R2/R1 - 1) Delta T = Temperature rise (°C) T1 = Initial temperature (°C) R1 = Initial resistance (Ohms) R2 = Final resistance (Ohms) R2 = K2R1 Temperature can also be found by making the R2/R1 ratio = the coefficient of correction graph in Fig. 2, and then finding the corresponding temperature. TEMPERATURE CORRECTION CHART FOR RESISTANCE Fig. 2 EXAMPLE: Catalog indicates coil resistance of 290 ohm at 25°C. What is the value at 125°C? From the chart: 290 x 1.39 = 403.31 Ohms. Date of issue: 6/00 - 16 - Page 2 of 2 N°104 Application notes "SMART" CONTACTORS SMART CONTACTORS are hybrid devices combining standard production power relays with an electronic module and electrical sensor. Their primary purpose is to control the flow of power to equipment without the use of the conventional circuit breaker panel. They are controlled by and provide information to a logic network or host computer. The functions and requirements of "SMART CONTACTORS" will vary, depending on the power distribution or control system involved. Leach International provides "SMART" capability from 25 amperes to 305 amperes, single and three phase AC, and up to 1000 amperes DC. In addition to I²t curves, devices can be configured to respond to current, voltage or power. The standard operating temperature range is -55°C to +71°C, and weights will vary in junction of the application. The photos below show two current applications: Fig. 1. Used in APU start circuit on board commercial aircraft. Fig. 2. Used in three phase secondary bus distribution onboard military fighter aircraft. Figure 1 Date of issue: 6/00 Figure 2 - 23 - Page 1 of 1 N°105 Application notes AIRCRAFT GROUND FAULT DETECTION AND PROTECTION Leach International, the innovator of the "Smart Contactor" in response to the need for ground fault protection, has developed several contactors with capabilities to detect and isolate ground faults. As aircraft become more electrical and, as existing aircraft age, the problems with wiring and wire harnesses become more significant. Incidents resulting in catastrophic loss of aircraft have been attributed to faults of this category. Conventional electromechanical protection devices, i.e., circuit breakers are not suitable for detecting and isolating this type of fault. The use of a Ground Fault Sensing Contactor (GFSC) provides protection for personnel and equipment against this type of fault. Ground Fault Concept The concept of ground fault detection is an established and proven technique. A common method of fault detection is to compare the total electrical current flowing to the load with the current that returns from the load. A difference between these two values indicates that the current is returning to the source through an unexpected path, i.e., ground fault. Several configurations of these devices have been designed and developed for airborne applications and are currently flying on a number of commercial aircraft. These units have the capability to compare the load current through the device versus current measured by an external sensor and trip (open) the contactor if the difference between the current values exceeds a predefined level. The external sensor is normally used on the return path of the current to its source; therefore comparison is performed between the input current (to the load) and the output current (from the load). LEACH Ground Fault Protection The Ground Fault Protection (GFP) feature may be incorporated into existing Leach International products. The "H" contactor, for example, is a 3PDT device that is used extensively in aircraft and military vehicle electrical systems. This device, rated for 60 amperes, is fairly compact and light. Leach, using miniaturization techniques and exotic magnetic material has managed to incorporate the GFP within this assembly with minimal impact to its size. The interface and the footprint of this unit remains intact, allowing direct replacement of existing units with units featuring GFP. The height of the unit is increased by .40" and its weight is increased by only 2 ounces. One of the major achievements with this design is the reduction in "release" time of the contactor. Due to potential danger of a fault, it should be expeditiously interrupted and isolated. The normal release time of the contactors (greater than 20 ms) is not acceptable for this application. Personnel injury (electrocution) and substantial damage to the wiring or aircraft equipment could occur within this period. It is imperative that the fault be detected and interrupted within 10 ms or faster to minimize the damage. Leach, with the aid of a proprietary circuit, has managed to reduce the release time of the contactor to less than 8 ms without any degradation to its performance. The GFP circuit can be incorporated in a majority of Leach International products including smaller relays. Obviously, the determinant for the size of the relay is the potential fault current. Date of issue: 3/02 - 24 - Page 1 of 1 N°007 Application notes SUPPRESSOR DEVICES FOR RELAY COILS The inductive nature of relay coils allows them to create magnetic forces which are converted to mechanical movements to operate contact systems. When voltage is applied to a coil, the resulting current generates a magnetic flux, creating mechanical work. Upon deenergizing the coil, the collapasing magnetic field induces a reverse voltage (also known as back EMF) which tends to maintain current flow in the coil. The induced voltage level mainly depends on the duration of the deenergization. The faster the switch-off, the higher the induced voltage. All coil suppression networks are based on a reduction of speed of current decay. This reduction may also slow down the opening of contacts, adversly effecting contact life and reliability. Therefore, it is very important to have a clear understanding of these phenomena when designing a coil suppression circuitry. Typical coil characteristics On the graph below, the upper record shows the contacts state. (High level NO contacts closed, low level NC contacts closed, intermediate state contact transfer). The lower record shows the voltage across the coil when the current is switched off by another relay contact. The surge voltage is limited to -300V by the arc generated across contact poles. Discharge duration is about 200 mircoseconds after which the current change does not generate sufficient voltage. The voltage decreases to the point where the contacts start to move, at this time, the voltage increases due to the energy contained in the NO contact springs. The voltage decreases again during transfer, and increases once more when the magnetic circuit is closed on permanent magnet. Operating times are as follows: Time to start the movement 1.5ms Total motion time 2.3ms Transfer time 1.4ms Contact State Date of issue: 6/00 -8- Page 1 of 4 Types of suppressors: Passive devices. The resistor capacitor circuit It eliminates the power dissipation problem, as well as fast voltage rises. With a proper match between coil and resistor, approximate capacitance value can be calculated from: C = 0.02xT/R, where T = operating time in milliseconds R = coil resistance in kiloOhms C = capacitance in microFarads The series resistor must be between 0.5 and 1 times the coil resistance. Special consideration must be taken for the capacitor inrush current in the case of a low resistance coil. The record shown opposite is performed on the same relay as above. The operation time becomes: - time to start the movement 2.3ms - transfer time 1.2ms The major difficulty comes from the capacitor volume. In our example of a relay with a 290 Ω coil and time delay of 8 ms, a capacitance value of C=0.5 uF is found. This non polarized capacitor, with a voltage of 63V minimum, has a volume of about 1cm3. For 150V, this volume becomes 1.5 cm3. Date of issue: 6/00 -9- Page 2 of 4 The bifilar coil The principle is to wind on the magnetic circuit of the main coil a second coil shorted on itself. By a proper adaptation of the internal resistance of this second coil it is possible to find an acceptable equilibrium between surge voltage and reduction of the opening speed. To be efficient at fast voltage changes, the coupling of two coils must be perfect. This implies embedded windings. The volume occupied by the second coil reduces the efficiency of the main coil and results in higher coil power consumption. This method cannot be applied efficiently to products not specifically designed for this purpose. The resistor (parallel with the coil) For efficient action, the resistor must be of the same order of magnitude as the coil resistance. A resistor 1.5 times the coil resistance will limit the surge to 1.5 times the supply voltage. Release time and opening speed are moderately affected. The major problem is the extra power dissipated. Semi-conductor devices The diode It is the most simple method to totally suppress the surge voltage. It has the major disadvantage of the higher reduction of contact opening speed. This is due to the total recycling, through the diode, of the energy contained in the coil itself. The following measurement is performed once again on the same relay. Operation times are given by the upper curve: - time to start the movement 14ms - transfer time 5ms These times are multiplied by a coefficient from 4 to 8. The lower curve shows the coil current. The increase prior to NO contact opening indicates that the contact spring dissipates its energy. At the opening time the current becomes constant as a result of practically zero opening speed. Due to this kind of behavior, this type of suppression must be avoided for power relays. For small relays which have to switch low currents of less than 0.2 A, degradation of life is not that significant and the method may be acceptable. Date of issue: 6/00 - 10 - Page 3 of 4 The diode + resistor network It eliminates the inconvenience of the resistor alone, explained above, and it limits the action of a single diode. It is now preferred to used the diode + zener network. The diode + zener network Like the resistor, the zener allows a faster decurrent decay. In addition it introduces a threshold level for current conduction which avoids the recycling of energy released during contact movement. The lower curve on the opposite record demonstrates those characteristics. Voltage limitation occurs at 42V. The two voltages spikes generated by internal movement are at lower levels than zener conduction. As a result, no current is recycled in the coil. The opening time phases are as follows: - time to start the movement 2.6ms - total motion time 2.4ms - transfer time 1.4ms The release time is slightly increased. The contacts' opening speed remains unchanged. Date of issue: 6/00 - 11 - Page 4 of 4