QTD20.241

QTD20.241 24V, 20A, DC INPUT Q-Series DC/DC CONVERTER ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ DC 600V Input Optimized for Intermediate DC-bus of Drive Systems Two Input Fuses for DC 600V included 95% Full Load and Excellent Partial Load Efficiencies Width only 65mm, Weight only 890g 25% BonusPower, 600W for up to 4s Active Filtering of Input Transients Full Power Between -25°C and +60°C Extremely Low Input Inrush Current Surge Reverse Input Polarity Protection DC-OK Relay Contact Quick-connect Spring-clamp Terminals 3 Year Warranty PRODUCT DESCRIPTION SHORT-FORM DATA Modern machines typically use maintenance-free AC-motors which are controlled by frequency converters or servo amplifiers. Such devices have an intermediate DC-bus where all individual drives are connected. The QTD20 DC/DC converter can be connected directly to the intermediate DC-bus. In case of a mains failure, the QTD20 utilizes the power from the DC-bus capacitors which are charged from the kinetic energy of the motor until the motor has come to a complete stop. Output voltage Adjustment range Output current The intermediate DC-bus is usually unfiltered and have high EMI noise so the QTD20 has a very robust input stage and an appropriate input filter included. Additionally, the QTD20 is UL 508 approved and is equipped with input fuses which are rated and tested for 600Vdc applications. L1 f + L2 L3 PE Motor f PE + QTD + PE Motor DC Load, Controller QTD20.241 Accessory ZM1.WALL ZM14.SIDE UF20.241 YR40.241 Output ripple Input voltage Input current Inrush current Efficiency Losses Temperature range Derating Hold-up time Dimensions Weight nominal continuous short term (4s) continuous short term (4s) 20Hz to 20MHz -20%/+40% at 600Vdc at 600Vdc at 600Vdc operational +60 to +70°C at 600Vdc WxHxD MAIN APPROVALS ORDER NUMBERS DC/DC converter Output power DC 24V 24 - 28V 20 – 17.5A 25 – 21.4A 480W 600W < 100mVpp DC 600V 0.85A typ. 1.5A peak 95.0% 25.5W -25°C to +70°C 12W/°C typ. 22ms 65x124x127mm 890g For details and the complete approval list, see chapter 19. Wall mount bracket Side mount bracket Buffer unit Redundancy module UL 508 Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 1/29 QTD20.241 24V, 20A, DC INPUT Q-Series INDEX Page 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. Intended Use ................................................................ 3 Installation Instructions ................................................ 3 Input ............................................................................. 5 Input Inrush Current ..................................................... 6 Output .......................................................................... 7 Hold-up Time ................................................................ 9 DC-OK Relay Contact .................................................... 9 Efficiency and Power Losses ....................................... 10 Lifetime Expectancy ................................................... 11 MTBF .......................................................................... 11 Functional Diagram .................................................... 12 Terminals and Wiring ................................................. 13 Front Side and User Elements .................................... 14 EMC ............................................................................ 15 Environment ............................................................... 16 Protection Features .................................................... 17 Safety Features........................................................... 17 Dielectric Strength ...................................................... 18 Approved, Fulfilled or Tested Standards .................... 19 Regulatory Product Compliance ................................. 19 Page 21. Physical Dimensions and Weight ............................... 20 22. Accessories................................................................. 21 22.1. ZM1.WALL – Wall/Panel mounting .................. 21 22.2. ZM14.SIDE - Side Mounting Bracket................. 21 22.3. UF20.241 - Buffer module ................................ 22 22.4. YR40.241 - Redundancy Module ...................... 22 23. Application Notes....................................................... 23 23.1. Repetitive Pulse Loading .................................. 23 23.2. Peak Current Capability .................................... 24 23.3. External Input Protection ................................. 24 23.4. Charging of Batteries ........................................ 25 23.5. Output Circuit Breakers .................................... 26 23.6. Series Operation............................................... 26 23.7. Parallel Use to Increase Output Power ............ 27 23.8. Parallel Use for Redundancy ............................ 27 23.9. Inductive and Capacitive Loads ........................ 27 23.10. Back-feeding Loads .......................................... 28 23.11. Use in a Tightly Sealed Enclosure ..................... 28 23.12. Mounting Orientations ..................................... 29 The information given in this document is correct to the best of our knowledge and experience at the time of publication. If not expressly agreed otherwise, this information does not represent a warranty in the legal sense of the word. As the state of our knowledge and experience is constantly changing, the information in this data sheet is subject to revision. We therefore kindly ask you to always use the latest issue of this document (available under www.pulspower.com). No part of this document may be reproduced or utilized in any form without our prior permission in writing. Some parts of this unit are patent by PULS (US patent No 091662,063, Des. 424,529, …). TERMINOLOGY AND ABREVIATIONS PE and symbol PE is the abbreviation for Protective Earth and has the same meaning as the symbol . Earth, Ground This document uses the term “earth” which is the same as the U.S. term “ground”. t.b.d. To be defined, value or description will follow later. DC 600V A figure displayed with the AC or DC before the value represents a nominal voltage with standard tolerances included. E.g.: DC 12V describes a 12V battery disregarding whether it is full (13.7V) or flat (10V) 600Vdc A figure with the unit (Vac or Vdc) at the end is a momentary figure without any additional tolerances included. may A key word indicating flexibility of choice with no implied preference. shall A key word indicating a mandatory requirement. should A key word indicating flexibility of choice with a strongly preferred implementation. Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 2/29 QTD20.241 24V, 20A, DC INPUT Q-Series 1. INTENDED USE This device is designed for installation in an enclosure and is intended for commercial use, such as in industrial control, process control, monitoring and measurement equipment or the like. This device is optimized to operate from the intermediate bus of a drive system. It can cope with the EMI disturbances on such busses. Do not use this device in equipment, where malfunctioning may cause severe personal injury or threaten human life without additional appropriate safety devices, that are suited for the end-application. If this device is used in a manner outside of its specification, the protection provided by the device may be impaired. 2. INSTALLATION INSTRUCTIONS WARNING - Risk of electrical shock, fire, personal injury or death. Turn power off before working on the device and protect against inadvertent re-powering. Do not open, modify or repair the device. Use caution to prevent any foreign objects from entering into the housing. Do not use in wet locations or in areas where moisture or condensation can be expected. Do not touch during power-on, and immediately after power-off. Hot surface may cause burns. Obey the following installation instructions: This device may only be installed and put into operation by qualified personnel. This device does not contain serviceable parts. The tripping of an internal fuse is caused by an internal defect. If damage or malfunction should occur during installation or operation, immediately turn power off and send unit to the factory for inspection. Install device in an enclosure providing protection against electrical, mechanical and fire hazards. Install the device onto a DIN rail according to EN 60715 with the input terminals on the bottom of the device. Other mounting orientations require a reduction in output current. Make sure that the wiring is correct by following all local and national codes. Use appropriate copper cables that are designed for a minimum operating temperature of 60°C for ambient temperatures up to +45°C, 75°C for ambient temperatures up to +60°C and 90°C for ambient temperatures up to +70°C. Ensure that all strands of a stranded wire enter the terminal connection. Use ferrules for wires on the input terminals. The device is designed for pollution degree 2 areas in controlled environments. No condensation or frost is allowed. The enclosure of the device provides a degree of protection of IP20. The enclosure does not provide protection against spilled liquids. The isolation of the devices is designed to withstand impulse voltages up to 4kV according to IEC 60664-1. The device is designed as “Class of Protection I” equipment according to IEC 61140. Do not use without a proper PE (Protective Earth) connection. The device is designed to be supplied from a DC input voltage derived from a 3-phase mains network by means of a B6 bridge rectifier. The device is not designed to be used on corner grounded delta systems. Follow the wiring scheme option 1 shown in this document. The input can also be supplied by batteries or similar DC sources. Since the continuous voltage between the input voltage and the PE/earth potential must not exceed 440V r.m.s., the input voltage must be grounded at about half the supply voltage as shown in option 2 in the wiring scheme drawing. Do not ground the positive or negative input voltage pole. Check for correct input polarity. The device will not operate when the voltage is reversed. A disconnecting means shall be provided for the input of the device. The device is designed for convection cooling and does not require an external fan. Do not obstruct airflow and do not cover ventilation grid! The device is designed for altitudes up to 5000m. Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 3/29 QTD20.241 24V, 20A, DC INPUT Q-Series Keep the following minimum installation clearances: 40mm on top, 20mm on the bottom, 5mm left and right side. Increase the 5mm to 15mm in case the adjacent device is a heat source. When the device is permanently loaded with less than 50%, the 5mm can be reduced to zero. The device is designed, tested and approved for branch circuits up to 16A (IEC) and 15A (UL) without additional protection device. If an external fuse is utilized, do not use circuit breakers smaller than 6A B- or 3A C-Characteristic to avoid a nuisance tripping of the circuit breaker. The maximum surrounding air temperature is +70°C. The operational temperature is the same as the ambient or surrounding air temperature and is defined 2cm below the device. The device is designed to operate in areas between 5% and 95% relative humidity. Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 4/29 QTD20.241 24V, 20A, DC INPUT Q-Series 3. INPUT Input Input range max. DC 600V -20%/+40% 480-840Vdc 360-480Vdc 840-900Vdc 1000Vdc max. max. max. 600V R.M.S. ±900Vpk 1000V/µs max. typ. typ. typ. typ. typ. typ. max. 50Vpp 50Hz-40kHz 450Vdc Steady-state value, load independent, see Fig. 3-1 325Vdc Steady-state value, load independent, see Fig. 3-1 0.79A At 24V, 20A, see Fig. 3-3 350ms See Fig. 3-2 70ms At 24V, 20A, only resistive load see Fig. 3-2 110ms At 24V, 20A, resistive load with an additional 20mF capacitor 500mV See Fig. 3-2 Allowed without any limitations nom. Allowed voltage input to Earth Slew rate for voltages between input and Earth (ground) Allowed input ripple voltage Turn-on voltage Shut-down voltage Input current Start-up delay Rise time Turn-on overshoot External capacitors on input Max. 60s or with reduced output current, see Fig. 5-2 Max. 60s or with reduced output current, see Fig. 5-2 Absolute maximum input voltage with no damage to the DC/DC converter. Above 900Vdc, the output will switch off and will turn-on again, when the input voltage falls below 850Vdc. Continuous, IEC 60664-1 Peak value, allowed for transients Fig. 3-1 Input voltage range POUT B A Turn-on Shut-down B A: Input Range B: < 60s or with derating 900Vdc 840Vdc 450Vdc 480Vdc 325Vdc 360Vdc VIN QTD20.241 Fig. 3-2 Turn-on behavior, definitions Fig. 3-3 Input current vs. output load at 24V Input Current, typ. Intput Voltage 1.0A 0.8 Output Voltage - 5% Start-up delay Rise Time Overshoot 0.6 0.4 0.2 Output Current 0 2 4 6 8 10 12 14 16 18 20A Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 5/29 QTD20.241 24V, 20A, DC INPUT Q-Series 4. INPUT INRUSH CURRENT The DC/DC converter is equipped with an active inrush current limitation circuit, which limits the input inrush current after turn-on and after short input voltage interruptions to a very low value. Inrush current*) Inrush energy Inrush delay *) DC 600V 3Apeak 1.6Apeak 1A2s 350ms max. typ. max. typ. Over entire temperature range Over entire temperature range Over entire temperature range The charging current into EMI suppression capacitors is disregarded in the first microseconds after switch-on. Fig. 4-1 Typical turn-on behavior at nominal load and 25°C ambient temperature Input Voltage Output Voltage Input Current Input: Output: Ambient: 600Vdc 24V, 20A 25°C Upper curve: Medium curve: Lower curve: Time base: Input voltage 100V/Div Output voltage 5V/DIV Input current 1A/DIV 100ms/DIV Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 6/29 QTD20.241 24V, 20A, DC INPUT Q-Series 5. OUTPUT Output voltage Adjustment range Factory setting Line regulation Load regulation Ripple and noise voltage Output current – continuous Output current – up to 4s 1) Output power – continuous Output power – up to 4s 1) BonusPower time BonusPower recovery time Overload behavior Short-circuit current 2) Output capacitance nom. max. typ. max. max. max. nom. nom. nom. nom. nom. nom. typ. typ. 24V 24-28V 30V 3) 24.1V 10mV 100mV 100mVpp 20A 4) 17.5A 4) 25A 21.4A 480W 600W 4s 7s Guaranteed At clockwise end position of potentiometer ±0.2%, at full load, cold unit At 480-840Vdc voltage change Static value, 0A→20A 20Hz to 20MHz, 50Ohm At 24V, input: 480-840Vdc, see Fig. 5-1 At 28V, input: 480-840Vdc, see Fig. 5-1 At 24V, input: 480-840Vdc, see Fig. 5-1 and Fig. 5-3 At 28V, input: 480-840Vdc, see Fig. 5-1 and Fig. 5-3 At 24-28V At 24-28V Duration until the output voltage dips, see Fig. 5-3 Overload free time to reset power manager, see Fig. 5-4 min. max. min. max. typ. cont. current 20A 23A 25A 28A 950µF See Fig. 5-1 Continuous, load impedance 50mOhm, see Fig. 5-1 Continuous, load impedance 50mOhm, see Fig. 5-1 Short-term (4s), load impedance 50mOhm, see Fig. 5-1 Short-term (4s), load impedance 50mOhm, see Fig. 5-1 Included in the DC/DC converter 1) BonusPower, short term power capability (up to typ. 4s) The DC/DC converter is designed to support loads with a higher short-term power requirement without damage or shutdown. The short-term duration is hardware controlled by an output power manager. This BonusPower is repeatedly available. Detailed information can be found in chapter 23.1. If the DC/DC converter is loaded longer with the BonusPower than shown in the bonus-time diagram (see Fig. 5-3), the max. output power is automatically reduced to 480W. 2) Discharge current of output capacitors is not included. 3) This is the maximum output voltage which can occur at the clockwise end position of the potentiometer due to tolerances. It is not guaranteed value which can be achieved. The typical value is about 28.5V. 4) Reduce output current according to Fig. 5-2 for the extended input voltage ranges from 360-480Vdc and 840-900Vdc. Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 7/29 QTD20.241 24V, 20A, DC INPUT Q-Series Fig. 5-1 Output voltage vs. output current, typ. Adjustment Range Output Voltage 28V Fig. 5-2 Output current vs. input voltage Allowed Output Current at 24V 25A 20 20 continuous short -t erm 24 16 12 8 4 0 Output Current 0 5 10 15 20 25 30A f or t yp. 4s continuous 3.5mm E.g. screws, small parts yes Output shut-down with automatic restart MOV (Metal Oxide Varistor) included The unit is equipped with two internal input fuses (+ line and line) which protect the unit against internal short circuits and ground faults. The fuses are not user accessible. A tripping of an internal fuse is caused by an internal fault. In case of a protection event, audible noise may occur. 17. SAFETY FEATURES Input / output separation*) Class of protection Isolation resistance PE resistance Touch current (leakage current) *) SELV EN 62477-1 PELV IEC/EN 60204-1, EN 62477-1, IEC 62103, IEC 60364-4-41 I PE (Protective Earth) connection required > 500MOhm Input to output, 500Vdc < 0.1Ohm The leakage current, which is produced by the DC/DC converter itself, depends on the input voltage ripple and need to be investigated in the final application. For a smooth DC input voltage, the produced leakage current is less than 100µA. double or reinforced insulation Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 17/29 QTD20.241 24V, 20A, DC INPUT Q-Series 18. DIELECTRIC STRENGTH The output voltage is floating and has no ohmic connection to the ground. Type and factory tests are conducted by the manufacturer. Field tests may be conducted in the field using the appropriate test equipment which applies the voltage with a slow ramp (2s up and 2s down). Connect all input poles together as well as all output poles before conducting the test. When testing, set the cut-off current settings to the value in the table below. Type test 60s A 2500Vac B 3000Vac C 500Vac D 500Vac Factory test 5s 2500Vac 2500Vac 500Vac 500Vac Field test 5s 2000Vac 2000Vac 500Vac 500Vac Cut-off current setting > 10mA > 10mA > 30mA > 1mA Fig. 18-1 Dielectric strength Input + DC-ok B* ) - B A D Output Earth C + - To fulfil the PELV requirements according to EN 60204-1 § 6.4.1, we recommend that either the + pole, the – pole or any other part of the output circuit shall be connected to the protective earth system. This helps to avoid situations in which a load starts unexpectedly or can not be switched off when unnoticed earth faults occur. B*) When testing input to DC-OK ensure that the max. voltage between DC-OK and the output is not exceeded (column D). We recommend connecting DC-OK pins and the output pins together when performing the test. Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 18/29 QTD20.241 24V, 20A, DC INPUT Q-Series 19. APPROVED, FULFILLED OR TESTED STANDARDS UL 508 UL Certificate Listed equipment for category NMTR - Industrial Control Equipment Applicable for US and Canada E-File: E198865 IEC 61010-2-201 Agency Certificate Electrical Equipment for Measurement, Control and Laboratory Use Particular requirements for control equipment VDMA 24364 Paint Wetting Impairment Substances Test (or LABS-Test) Tested for Zone 2 and test class C1 according to VDMA 24364-C1-L/W for solvents and water-based paints 20. REGULATORY PRODUCT COMPLIANCE EU Declaration of Conformity REACH Regulation (EU) WEEE Regulation The CE mark indicates conformance with the - EMC directive - LVD directive Manufacturer's Declaration EU regulation regarding the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) fulfilled. EU Regulation (EC) 1907/2006. Manufacturer's Declaration EU Regulation on Waste Electrical and Electronic Equipment Registered as business to business (B2B) products. EU Regulation 2012/19/EU KC Certification The KC mark indicate registered under the Clause 3, Article 58-2 of Radio Waves Art of the Republic of Korea EAC TR Registration EAC Certificate EAC EurAsian Conformity - Registration Russia, Kazakhstan and Belarus 8504408200, 8504409000 Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 19/29 QTD20.241 24V, 20A, DC INPUT Q-Series 21. PHYSICAL DIMENSIONS AND WEIGHT Width Height Depth Weight DIN rail Housing material Installation clearances 65mm 124mm 127mm The DIN rail depth must be added to the unit depth to calculate the total required installation depth. 890g Use 35mm DIN rails according to EN 60715 or EN 50022 with a height of 7.5 or 15mm. Body: Aluminium alloy Cover: Zinc-plated steel See chapter 2 Fig. 21-1 Front view Fig. 21-2 Side view Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 20/29 QTD20.241 24V, 20A, DC INPUT Q-Series 22. ACCESSORIES 22.1. ZM1.WALL – WALL/PANEL MOUNTING This bracket is used to mount the QTD20 DC/DC converter on a wall/panel without utilizing a DIN rail. The two aluminum brackets and the black plastic slider of the unit have to be detached, so that the steel brackets can be mounted. Fig. 22-1 Wall/panel mounting Fig. 22-2 Wall/panel mounting Fig. 22-3 Mounting Dimensions - Wall mounting bracket 22.2. ZM14.SIDE - SIDE MOUNTING BRACKET This bracket is used to mount the QTD20 DC/DC converter sideways with or without utilizing a DIN rail. The two aluminum brackets and the black plastic slider of the unit have to be detached, so that the steel brackets can be mounted. For sideway DIN rail mounting, the removed aluminum brackets and the black plastic slider need to be mounted on the steel bracket. Fig. 22-4 Side mounting without DIN rail brackets Fig. 22-5 Side mounting with DIN rail brackets Fig. 22-6 Mounting Dimensions Side mounting bracket Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 21/29 QTD20.241 24V, 20A, DC INPUT Q-Series 22.3. UF20.241 - BUFFER MODULE This buffer unit is a supplementary device for DC 24V power supplies and DC/DC converter. It delivers power to bridge typical mains failures or extends the hold-up time after turn-off of the AC or DC power. In times when the DC/DC converter provides sufficient voltages, the buffer unit stores energy in the integrated electrolytic capacitors. In case of mains voltage fault, this energy is released again in a regulated process. The buffer unit does not require any control wiring. It can be added in parallel to the load circuit at any given point. Buffer units can be added in parallel to increase the output ampacity or the hold-up time. AC Power Supply Buffer Unit(s) Load + - DC 22.4. YR40.241 - REDUNDANCY MODULE The YR40.241 redundancy module is equipped with two input channels (20A each), which are individually decoupled by utilizing MOSFET technology. The output current can go as high as 40A. Using MOSFET instead of diodes reduces the heat generation and the voltage drop between input and output. The YR40.241 does not require an additional auxiliary voltage and is selfpowered even in case of a short circuit across the output. Due to the low power losses, the unit is very slender and only requires 36mm width on the DIN rail. Fig. 22-7 Typical 1+1 Redundant configuration for 20A with one dual redundancy module und two DC/DC converters Fig. 22-8 Typical N+1 Redundant configuration for 60A with two dual redundancy modules and four DC/DC converters Failure Monitor Failure Monitor ++ + - + - -- DC24V,20A OK QTD20.241 + - Input Input 2 1 YR40.241 Redundancy Module ++ + + - - + - + - -- DC24V,20A OK QTD20.241 QTD20.241 Output PE ++ -- DC24V,20A OK + PE - Input Input 2 1 YR40.241 Redundancy Module ++ QTD20.241 Output PE -- DC24V,20A OK + + - - ++ + - + - -- DC24V,20A OK QTD20.241 + PE - PE Input Input 2 1 YR40.241 Redundancy Module ++ QTD20.241 Output + + - 20A Load I -- DC24V,20A OK - PE 60A Load I I + + - - PE PE I I Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany I 22/29 QTD20.241 24V, 20A, DC INPUT Q-Series 23. APPLICATION NOTES 23.1. REPETITIVE PULSE LOADING Typically, a load current is not constant and varies over time. This DC/DC converter is designed to support loads with a higher short-term power demand (=BonusPower). The short-term duration is hardware controlled by an output power manager and is available on a repeated basis. If the BonusPower load lasts longer than the hardware controller allows it, the output voltage will dip and the next BonusPower is available after the BonusPower recovery time (see chapter 5) has elapsed. To avoid this, the following rules must be met: a) The power demand of the pulse must be below 125% of the nominal output power. b) The duration of the pulse power must be shorter than the allowed BonusPower time. (see output chapter) c) The average (R.M.S.) output current must be below the specified continuous output current. If the R.M.S. current is higher, the unit will respond with a thermal shut-down after a period of time. Use the maximum duty cycle curve (Fig. 23-2) to check if the average output current is below the nominal current. d) The duty cycle must be below 0.75. Fig. 23-1 Repetitive pulse loads, definitions Fig. 23-2 Max. duty cycle curve P0 = 10% P0 = 50% P0 = 75% Duty Cycle PPEAK TPEAK T0 0.75 max. 125% 0.6 100% 0.4 P0 = 100% 0.2 P0 PPEAK 0 100 P0 PPEAK T0 TPEAK Example: Base load (W) Pulse load (above 100%) Duration between pulses (s) Pulse duration (s) 105 DutyCycle = T0 = 110 115 120 125% Tpeak Tpeak + T0 Tpeak - (DutyCycle x Tpeak) DutyCycle A load is powered continuously with 240W (= 50% of the rated output load). From time to time a peak power of 600W (= 125% of the rated output load) is needed for 1 second. The question is: How often can this pulse be supplied without overloading the DC/DC converter? - Make a vertical line at PPEAK = 125% and a horizontal line where the vertical line crosses the P0 = 50% curve. Read the max. duty cycle from the duty cycle-axis (= 0.37) - Calculate the required pause (base load) length T0: - Result: The required pause length = 1.7s T0= Tpeak - (DutyCycle x Tpeak) - Max. repetition rate = pulse +pause length = 2.7s DutyCycle = 1s- (0.37 x 1s) 0.37 =1.7s More examples for pulse load compatibility: PPEAK 600W 600W 540W P0 480W 0W 240W TPEAK 1s 1s 1s T0 >25s >1.3s > 0.75s PPEAK 600W 600W 600W P0 240W 240W 240W TPEAK 0.1s 1s 3s T0 >0.16s >1.6s >4.9s Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 23/29 QTD20.241 24V, 20A, DC INPUT Q-Series 23.2. PEAK CURRENT CAPABILITY The DC/DC converter can deliver peak currents (up to several milliseconds) which are higher than the specified short term currents. This helps to start current demanding loads. Solenoids, contactors and pneumatic modules often have a steady state coil and a pick-up coil. The inrush current demand of the pick-up coil is several times higher than the steady-state current and usually exceeds the nominal output current (including the BonusPower). The same situation applies when starting a capacitive load. The peak current capability also ensures the safe operation of subsequent circuit breakers of load circuits. The load branches are often individually protected with circuit breakers or fuses. In case of a short or an overload in one branch circuit, the fuse or circuit breaker need a certain amount of over-current to open in a timely manner. This avoids voltage loss in adjacent circuits. The extra current (peak current) is supplied by the power converter and the built-in large sized output capacitors of the DC/DC converter. The capacitors get discharged during such an event, which causes a voltage dip on the output. The following two examples show typical voltage dips: Fig. 23-3 Peak load with 2x the nominal current for 50ms, typ. Fig. 23-4 Peak load with 5x the nominal current for 5ms, typ. Output Voltage 24V Output Voltage 24V 100A 40A 4V 13V Output Current 0A Output Current 0A 10ms/DIV 1ms/DIV 40A Peak load (resistive) for 50ms Output voltage dips from 24V to 13V. 100A Peak load (resistive) for 5ms Output voltage dips from 24V to 4V. Please note: The DC-OK relay triggers when the voltage dips more than 10% for longer than 1ms. Peak current voltage dips typ. typ. typ. from 24V to 13V from 24V to 4V from 24V to 4V At 40A for 50ms, resistive load At 80A for 2ms, resistive load At 80A for 5ms, resistive load 23.3. EXTERNAL INPUT PROTECTION The unit is tested and approved for branch circuits up to 15A (U.S.A.) and 16A (IEC). An external protection is only required if the supplying branch has an ampacity greater than this. Check also local codes and local requirements. In some countries local regulations might apply. If an external fuse is necessary or utilized, minimum requirements need to be considered to avoid nuisance tripping of the circuit breaker. A minimum value of 6A B- or 3A C-Characteristic breaker should be chosen. Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 24/29 QTD20.241 24V, 20A, DC INPUT Q-Series 23.4. CHARGING OF BATTERIES The DC/DC converter can be used to charge lead-acid or maintenance free batteries. (Two 12V batteries in series) Instructions for charging batteries: a) Set output voltage (measured at no load and at the battery end of the cable) very precisely to the end-of-charge voltage. End-of-charge voltage 27.8V 27.5V 27.15V 26.8V Battery temperature 10°C 20°C 30°C 40°C b) Use a 25A circuit breaker (or blocking diode) between the DC/DC converter and the battery. c) Ensure that the output current of the DC/DC converter is below the allowed charging current of the battery. d) Use only matched batteries when putting 12V types in series. e) The return current to the DC/DC converter (battery discharge current) is typ. 16mA when the DC/DC converter is switched off (except in case a blocking diode is utilized). Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 25/29 QTD20.241 24V, 20A, DC INPUT Q-Series 23.5. OUTPUT CIRCUIT BREAKERS Standard miniature circuit breakers (MCB’s or UL1077 circuit breakers) are commonly used for AC-supply systems and may also be used on DC branches. MCB’s are designed to protect wires and circuits. If the ampere value and the characteristics of the MCB are adapted to the wire size that is used, the wiring is considered as thermally safe regardless of whether the MCB opens or not. To avoid voltage dips and under-voltage situations in adjacent 24V branches which are supplied by the same source, a fast (magnetic) tripping of the MCB is desired. A quick shutdown within 10ms is necessary corresponding roughly to the ride-through time of PLC's. This requires power supplies with high current reserves and large output capacitors. Furthermore, the impedance of the faulty branch must be sufficiently small in order for the current to actually flow. The best current reserve in the DC/DC converter does not help if Ohm’s law does not permit current flow. The following table has typical test results showing which B- and C-Characteristic MCBs magnetically trip depending on the wire cross section and wire length. Fig. 23-5 Test circuit Power Supply AC MCB + + Wire length DC S1... Fault simulation switch *) Load S1 Maximal wire length*) for a fast (magnetic) tripping: 0.75mm² 1.0mm² 1.5mm² C-2A 31m 39m 59m 2.5mm² 86m C-3A C-4A C-6A 24m 15m - 31m 15m - 43m 32m - 68m 41m - B-6A 16m 25m 34m 58m B-10A - - - - - Don’t forget to consider twice the distance to the load (or cable length) when calculating the total wire length (+ and – wire). 23.6. SERIES OPERATION DC/DC converters of the same type can be connected in series for higher output voltages. It is possible to connect as many units in series as needed, providing the sum of the output voltage does not exceed 150Vdc. Voltages with a potential above 60Vdc are not SELV any more and can be dangerous. Such voltages must be installed with a protection against touching. Avoid return voltage (e.g. from a decelerating motor or battery) which is applied to the output terminals. Unit A Input Output + + Unit B Keep an installation clearance of 15mm (left / right) between two power supplies and avoid installing the power supplies on top of each other. Do not use power supplies in series in mounting orientations other than the standard mounting orientation (input terminals on the bottom of the unit). Load Input Output + - - Pay attention that leakage current, EMI, inrush current, harmonics will increase when using multiple DC/DC converters. Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 26/29 QTD20.241 24V, 20A, DC INPUT Q-Series 23.7. PARALLEL USE TO INCREASE OUTPUT POWER DC/DC converters and power supplies from the same series (Q-Series) can be paralleled to increase the output power. The output Unit A voltage shall be adjusted to the same value (±100mV) or the units can be left with the Input factory settings. If more than three units are connected in parallel, a fuse or circuit breaker with a rating of 25A is required on each output. Alternatively, a diode or redundancy module can also be utilized. Keep an installation clearance of 15mm (left / right) between two power supplies and avoid installing the DC/DC converters or power supplies on top of each other. Do not use DC/DC converters or power supplies in parallel in mounting orientations other than the standard mounting orientation (input terminals on the bottom of the unit) or in any other condition where a derating of the output current is required (e.g. altitude, above 60°C, …). + - Output + Unit B Load Input + - - Output Pay attention that leakage current, EMI, inrush current, harmonics will increase when using multiple DC/DC converters. 23.8. PARALLEL USE FOR REDUNDANCY DC/DC converters can be paralleled for redundancy to gain higher system availability. Redundant systems require a certain amount of extra power to support the load in case one DC/DC converter unit fails. The simplest way is to connect two DC/DC converters in parallel. This is called a 1+1 redundancy. In case one DC/DC converter unit fails, the other one is automatically able to support the load current without any interruption. Redundant systems for a higher power demand are usually built in a N+1 method. E.g. five DC/DC converters, each rated for 20A are paralleled to build a 80A redundant system. For N+1 redundancy the same restrictions apply as for increasing the output power, see also chapter 23.7. Please note: This simple way to build a redundant system does not cover failures such as an internal short circuit in the secondary side of the DC/DC converter. In such a case, the defective unit becomes a load for the other power supplies and the output voltage can not be maintained any more. This can be avoided by utilizing redundancy modules, which have decoupling devices (diodes or MOSFETs) included. Further information and wiring configurations can be found in chapter 22.4. Recommendations for building redundant power systems: a) b) c) Use separate input fuses for each DC/DC converter. A separate source for each supply when possible increases the reliability of the redundant system. Monitor the individual DC/DC converter units. Therefore, use the DC-OK relay contact of the QTD20.241. It is desirable to set the output voltages of all units to the same value (± 100mV) or leave it at the factory setting. 23.9. INDUCTIVE AND CAPACITIVE LOADS The unit is designed to supply any kind of loads, including capacitive and inductive loads. Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 27/29 QTD20.241 24V, 20A, DC INPUT Q-Series 23.10. BACK-FEEDING LOADS Loads such as decelerating motors and inductors can feed voltage back to the DC/DC converter. This feature is also called return voltage immunity or resistance against Back- E.M.F. (Electro Magnetic Force). This DC/DC converter is resistant and does not show malfunctioning when a load feeds back voltage to the DC/DC converter. It does not matter whether the DC/DC converter is on or off. The maximum allowed feed-back-voltage is 34Vdc. The absorbing energy can be calculated according to the built-in output capacitor which is specified in chapter 5. 23.11. USE IN A TIGHTLY SEALED ENCLOSURE When the DC/DC converter is installed in a tightly sealed enclosure, the temperature inside the enclosure will be higher than outside. In such situations, the inside temperature defines the ambient temperature for the DC/DC converter. The following measurement results can be used as a reference to estimate the temperature rise inside the enclosure. The DC/DC converter is placed in the middle of the box, no other heat producing items are inside the box Enclosure: Load: Input: Temperature inside enclosure: Temperature outside enclosure: Temperature rise: Rittal Typ IP66 Box PK 9519 100, plastic, 180x180x165mm 24V, 16A; (=80%) load is placed outside the box 600Vdc 54.9°C (in the middle of the right side of the DC/DC converter with a distance of 2cm) 22.6°C 32.6K Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 28/29 QTD20.241 24V, 20A, DC INPUT Q-Series 23.12. MOUNTING ORIENTATIONS Mounting orientations other than all terminals on the bottom require a reduction in continuous output power or a limitation in the maximum allowed ambient temperature. The amount of reduction influences the lifetime expectancy of the DC/DC converter. Therefore, two different derating curves for continuous operation can be found below: Curve A1 Recommended output current. Curve A2 Max allowed output current (results in approximately half the lifetime expectancy of A1). Fig. 23-6 Mounting Orientation A (Standard orientation) Output Current OUTPUT 20A 16 12 8 4 0 10 DC/DC Converter INPUT Fig. 23-7 Mounting Orientation B (Upside down) 20 30 40 50 60°C INPUT 20A 16 12 8 4 0 10 A2 A1 Ambient Temperature 20 30 40 50 60°C DC/DC Convert er OUTPUT Output Current 20A 16 12 8 4 0 10 A2 A1 Ambient Temperature 20 30 40 50 60°C Output Current OUTPUT DC/DC Convert er INPUT 20A 16 12 8 4 0 10 A2 A1 Ambient Temperature 20 30 40 50 60°C INPUT DC/DC Convert er Output Current OUTPUT Fig. 23-10 Mounting Orientation E (Horizontal ccw) Ambient Temperature Output Current Fig. 23-8 Mounting Orientation C (Table-top mounting) Fig. 23-9 Mounting Orientation D (Horizontal cw) A1 20A 16 12 8 4 0 10 A2 A1 Ambient Temperature 20 30 40 50 60°C Oct. 2022 / Rev. 2.3 DS-QTD20.241-EN All parameters are specified at 24V, 20A, 600Vdc input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. www.pulspower.com Phone +49 89 9278 0 Germany 29/29