XZ — Medical Low Noise AC/DC PSU 6-Slot

Q: Can I create a negative output from the Xgen?
A: Yes. All outputs in the Xgen are fully isolated outputs, so they can be referenced to a common point creating either a positive or negative output voltage. To create a negative 5V output for example, the +Vout terminal of the module should be connected to the common return (chassis ground, earth ground etc). The –Vout terminal will then deliver the -5V output. All outputs have 500V output-output isolation and 500V output-ground isolation.

Q: Can I connect 2 or more power supplies in parallel for higher current?
A: Yes. The Xgen series of power supplies can be parallel connected for higher power and current applications. The maximum Earth Leakage Current of the system is an important consideration for the system designer. Depending on the application, this figure will vary, for example in industrial equipment it is 3.5mA. The total leakage current from the power supplies should be calculated by adding the individual Maximum Earth Leakage of each power supply. E.g. 6 x XVD (each with maximum Earth Leakage of 300uA) will have a combined maximum Earth Leakage of 1.8mA. Earth Leakage current will vary with input line voltage. It is higher a 220VAC than 110VAC. Excelsys Technologies measures Earth Leakage at the worst case voltage of 250VAC. It is also important to note that other components in the system can contribute to Earth Leakage current and should be considered when calculating the maximum system Earth Leakage current.

Q: Can I use an Xgen in my Medical Equipment?
A: Yes. The Xmite, Xrite, Xvite and Xzite provide medically approved power supplies from 200W to 1340W. Our medically approved power supplies are CE marked for Safety and carry full EN60601-1 approvals meeting 4000KV isolation,less than 300uA Earth Leakage current and required creepage and clearances. Certificates and reports are available in our Technical Support section. For more details on medical power supplies, implementation and considerations, please visit our Medical Electronics section and our Application Notes section.

Q: Are Excelsys products RoHS compliant?
A: Yes. All Excelsys products meet the requirements of the RoHS (Reduction of Hazardous Substances) Directive. Our program of compliance was completed in 2006. The WEEE (Waste Electrical and Electronic Equipment) Directive covers a number of items including; large and small household appliances, Electric and Electronic tools, lighting and consumer equipment. Excelsys Technologies can confirm that our power supplies do not fall under the scope of the WEEE Directive. Note that some power supplies do fall under the scope of the WEEE Directive such as External power supplies.

Q: Can I remotely switch ON/OFF the Xgen?
A: Yes. The Xgen has global Inhibit/Enable function built in that allows users to remotely switch ON/OFF the power supply using a digital or analog signal. Furthermore, each of the isolated outputs can also be individually Inhibited/Enabled allowing users to sequence outputs and control their system start-up. For more details on how to implement these functions, please refer to the Xgen Designers Manual.

Q: Can I parallel connect power supplies for an N+1 redundancy system?
A: Yes. Parallel connecting powers supplies for operation in Redundant mode is an acceptable and often necessary practise for mission critical applications. To ensure correct operation each power supply must be capable of providing the full system load. The the power supplies should have their outputs connected in parallel via diodes. The diodes permit on power supply to fail without affecting the other. For more details see our Xgen Designers Manual and Application Notes section.

Q: I have a number of PowerMods in parallel and want to use the remote sense option, do I need to bring out all of the sense lines to my load?
A: All of the sense lines will need to be connected to the load, but the complexity of the wiring can be reduced by connecting all of the sense lines locally and bringing out one pair of sense lines to the load. Please refer to the designer’s manual for more details on this.

Q: I notice the Xg8 is a dual output, if I have an unbalanced load will it affect cross regulation?
A: No. Both outputs are fully floating and are isolated from each other. They also both have independent regulation which is not effected by the adjacent output.

Q: I notice that when I connect the sense pins the output voltage drops, even at no load. Is this that you would expect?
A: Yes. Due to the voltage ratio of our feedback divider chain when the sense lines are connected we would expect to see approx 200mV drop once the remote sense lines are connected.

Q: I have a battery charging application; do you recommend the use of a blocking diode?
A: The Xgen is designed to sink and source current in order to maintain its regulation set point. We also have a negative current limit to prevent damage to the freewheel fet in the event of excessive energy coming back form the load. In a battery charging application, where this energy is sufficiently high there is a possibility that this may be a source for potential damage, so Excelsys would always recommend a blocking diode for any battery charging application.

Q: Can I use a combination of units in parallel AND in series to give me my required voltage and power requirements?
A: Yes. The Xgen series is the most flexible power supply on the market

Q: Where is the voltage setpoint measured on a configured Xgen?
A: For powerMods Xg1 to Xg5 the output voltage is set at the positive and negative sense pins, i.e. Pin1 and Pin 2 of Connector J3. For powerMod Xg7 the output is set at the +Vout (Pin2) and -Vout (Pin 1) of the J4 connector. For powerMod Xg8 the output is set on the +Vout and -Vout pins for each output, i.e. Pin 4 through to Pin1 respectively of the connector J4.

Q: Are the fans always on and are they constant speed?
A: Yes. The Xgen powerPac consists of a fan cooled semi-enclosed chassis. An always-on consent speed fan is used to enable industry leading power densities of 15W/in3 and the 90% plus efficiencies up to the 1340Watts available. To increase fan life the Global Inhibit can be used to turn off the power supply under no load conditions (fan will be turned off) and for acoustic sensitive applications the Xgen series is available in a Low Acoustic Noise versions.

Q: Can I use a DC input voltage with the Xgen series?
A: Yes. As well as universal input voltage range from 85 to 264VAC the Xgen also works with 120 to 380VDC at the input.

Q: How do I set the voltage on individual powerMods when they are being used in parallel ?
A: First ensure that the powerMods DIPswitch I Share is set to ON for reach powerMod. Then attach the negative parallel link. Adjust the output voltage on powerMod1 to the required output. Measure the voltage difference between the positive terminals of powerMod 1 and power mod 2. Adjust the powerMod 2 voltage to minimize the delta and then attach the positive parallel links. Repeat this for each subsequent powerMod. Full details of this are provided in the powerMod Operation in Section 7 of the Xgen Designers Manual.

Q: Is the OVP (Over Voltage protection) latching or non latching ?
A: Overvoltage protection (OVP) is implemented as a two level scheme. Level One OVP is initiated when the output is between 110 to 115% of the Vset, this is non latching. Level Two OVP fixed relative to Vmax. If the output voltage rises to between 110 to 125% of Vmax the OVP is initiated. This is a latching protection and it is reset by removing and reinstating the input power. Full details of all the protection features of the Xgen series are given in Section 7 of the Designers Manual.