National Instruments FP-RLY-420 User's Manual
Contents
1. Electrical at 30 cpm 300 000 operations at 3 A 35 VDC 100 000 operations at 3 A 250 VAC National Instruments Corp 11 FP RLY 420 Maximum switching frequency Mechanical 20 operations per second Electrical 1 operation per second at maximum load Relays operate time 6 ms typical 8 ms max Relays release time 3 ms typical 4 ms max Relay bounce time 3 ms max Contact material Gold plated silver cadmium oxide Isolation CH GND and CH CH 3 000 Vrms Safety isolation working voltage CH GND only 250 Vrms designed per IEC 1010 as double insulated Physical Indicators Green POWER and READY indicators 8 green output state indicators Weight 160 g 5 6 oz Power Requirements Power from network module 1700 mW Environment Operating temperature 40 to 70 C Storage temperature 55 to 100 C Relative humidity 5 to 90 noncondensing CE Mark Compliance This product meets applicable EU directive s as follows Safety isolation EN 61010 double insulation for 250 Vrms working isolation in2. place when it is firmly seated Figure 1 Module Installation Diagram Alignment Slot Key Latch Guide Rails Terminal Base I O Module National Instruments Corp 3 FP RLY 420 Field Wiring The terminal base has connections for each of the eight relay channels and an external supply to power field devices Each relay channel of the FP RLY 420 has two terminals N O Normally Open and I C Isolated Common The external supply is not needed for the internal operation of the FP RLY 420 however you may connect an external supply to power field devices by connecting to the V and C terminals of the terminal base If you connect an external supply to the V and C terminals the total current supplied cannot exceed 6 A Table 1 lists the terminal assignments for the signals of each channel Table 1 Terminal Assignments Chan nel Terminal Numbers N O I C Vsup COM 0 1 2 17 18 1 3 4 19 20 2 5 6 21 22 3 7 8 23 24 4 9 10 25 26 5 11 12 27 28 6 13 14 29 30 7 15 16 31 32 FP RLY 420 4 www natinst com Figures 2a and 2b show examples of basic wiring connections Figure 2 Basic Field Connection Two Channels Shown Relay Output Circuit The outputs of the FP RLY 420 consist of Form A electromechanical relays The power up state is off open to ensure safe installation In the ON state the N O and I C contacts connect together to form a short circuit
3. ANY circuits that may contain hazardous voltages to the FP RLY 420 This section describes the isolation of the FP RLY 420 and its compliance with international safety standards The outputs are isolated from the backplane of the terminal base with an isolation barrier designed and tested to protect against fault voltages of up to 3000 Vrms In addition the FP RLY 420 provides double insulation compliant to UL and IEC safety standards for working common mode voltages of 250 Vrms Safety standards such as those published by UL and IEC require the use of double insulation between hazardous voltages and any human accessible parts or circuits You should never attempt to use any isolation product between human accessible parts such as DIN rails or monitoring stations and circuits that may be at hazardous potentials under normal conditions unless the product is specifically designed as the FP RLY 420 is for such an application Even when a product like the FP RLY 420 is used in applications with hazardous potentials follow these guidelines to ensure a safe total system The safety isolation of the FP RLY 420 is from input to output not between channels on the same module If any of the channels on a module are wired at a hazardous potential ensure that all other devices or circuits connected to that module are properly insulated from human contact FP RLY 420 10 www natinst com Do not share the external supply voltages
4. Choose the impedance of the loads so that the current switched by any one channel in the ON state is no more than 3 A In the ON state there is an effective resistance of 100 m between the N O and I C terminals which causes a voltage drop For example if the current is 3 A the voltage drop across the N O and I C terminals is 0 3 V V C Vsup N O N O I C a Total Current Less Than 6 Amps I C COM Vsup N O I C COM Load b Total Current Greater Than 6 Amps Load Load N O I C Load National Instruments Corp 5 FP RLY 420 Figure 3 shows the diagram of one channel s relay output circuit Figure 3 Relay Output Circuit The maximum switching capacity of each relay is 3 A up to 250 VAC or 35 VDC To switch greater DC voltages refer to Figure 4 Figure 4 Maximum Current vs DC Volts Contact Protection for Inductive Loads When inductive loads are connected to the relays a large counter electromotive force may occur at relay switching time because of the energy stored in the inductive load These flyback voltages can severely damage the relay contacts and greatly shorten the life of the relay It is best to limit these flyback voltages at your inductive load by installing across your inductive load a flyback diode for DC loads or a metal oxide varistor MOV for AC loads Refer to the next section Guidelines for Selecting Contact P
5. FieldPoint is a trademark of National Instruments Corporation Product and company names mentioned herein are trademarks or trade names of their respective companies 321904B 01 Copyright 1998 1999 National Instruments Corp All rights reserved June 1999 OPERATING INSTRUCTIONS FP RLY 420 8 Channel SPST Relay Module These operating instructions describe the installation features and characteristics of the FP RLY 420 For details on configuring and accessing the FP RLY 420 over a network refer to the user manual for the particular FieldPoint network module you are using with the FP RLY 420 Features The FP RLY 420 is a FieldPoint relay output module with the following features Eight Single Pole Single Throw SPST relay channels Switching capacity 3 A at 35 VDC or 250 VAC On Off LED indicators Hot plug and play operation 3 000 V input to output isolation Double insulated for 250 V safe working voltage 40 to 70 C operation Power Requirement The FP RLY 420 is powered via the local backplane bus from the FieldPoint network module The FP RLY 420 is a high power consumption module and requires more than the nominal power allocated to an I O module from the network module In some applications this could limit the number of I O modules that you can connect to a single network module When defining a FieldPoint system that uses an FP RLY 420 module you must calcula
6. V and C on the terminal base with other devices including other FieldPoint devices unless those devices are also isolated from human contact As with any hazardous voltage wiring ensure that all wiring and connections meet with applicable electrical codes or common sense practices Mount terminal bases in an area position or cabinet that prevents accidental or unauthorized access to wiring with hazardous voltages The isolation of the FP RLY 420 is certified as double insulated for normal operating voltages of 250 Vrms Do not use the FP RLY 420 as the sole isolating barrier between human contact and working voltages of more than 250 Vrms Specifications The following specifications are typical for the range 40 to 70 C unless otherwise noted Input Characteristics Number of channels 8 Relay type 1 Form A SPST Nonlatching Maximum Switching Capacity Resistive Load AC 3 A at 250 VAC DC 3 A at 35 VDC 2 A at 40 VDC 1 A at 55 VDC 0 4 A at 120 VDC Note Above 55 C ambient max 1 5 A per channel Minimum switching voltage 10 mA at 5 VDC On resistance 100 m Off state leakage 0 3 A at 250 VAC Expected Life Mechanical 20 106 operations min
7. e following chart Status Indicators Figure 5 shows the module label and status indicators You can remove the insertable label to see wiring diagrams for the input channels Figure 5 Status Indicators and Module Label Type of Load In Rush Current Resistive load Steady state current Solenoid load 10 to 20 times the steady state current Motor load 5 to 10 times the steady state current Incandescent lamp load 10 to 15 times the steady state current Mercury lamp load Approximately 3 times the steady state current Sodium vapor lamp load 1 to 3 times the steady state current Capacitive load 20 to 40 times the steady state current Transformer load 5 to 15 times the steady state current National Instruments Corp 9 FP RLY 420 After the module has been inserted into a terminal base and power is applied the green POWER indicator lights and the FP RLY 420 informs the network module of its presence When the network module recognizes the FP RLY 420 the network module sends initial configuration information to the FP RLY 420 After receiving this initial information the green READY indicator lights and the FP RLY 420 is in its normal operating mode In addition to the green POWER and READY indicators each channel has a numbered green output state indicator that lights when the channel is in the ON state Isolation and Safety Guidelines Caution Read the following information before attempting to connect
8. l Instruments Corp 7 FP RLY 420 Diode Circuit CR Circuits Varistor Circuit Diagram Notes Use in DC applications only Compared to RC type circuit delays release time 2 to 5 times values stated in catalog For larger voltages use diode with reverse breakdown 10 times circuit voltage and forward load circuit For smaller voltages use reverse breakdown voltage of 2 to 3 times power supply voltage Diagram Notes Circuit A is suitable for AC or DC applications but if used with AC voltage impedance of the load should be smaller than the CR circuit s Do not utilize for timer loads as leakage current can cause faulty operations Circuit B is suitable for AC or DC If the load is a relay or solenoid release times lengthen Effective when connected to both contacts power supply voltage across the load is 100 to 200 V Diagram Notes Effective for AC and DC applications Circuit slightly delays release time Effective when connected to both contacts power supply voltage across the load is 100 to 200 V Load Load Load Load FP RLY 420 8 www natinst com In Rush Current The type of load and its in rush current characteristics together with switching frequency can cause contact welding For loads with in rush current measure the steady state current and in rush current to determine the proper relay Some typical types of loads and the in rush current they create are summarized in th
9. rotection Circuits for more information N O I C COM C V Vsup 20 0 40 60 DC Volts Current Amps 80 100 120 5 1 1 5 2 2 5 3 Safe Operating Region FP RLY 420 6 www natinst com In addition the FP RLY 420 contains its own internal protection MOV to prevent excessively high voltage from being applied across the contacts The MOV is located between the N O and I C contacts of each relay but National Instruments still recommends the use of a protection circuit across your inductive load Guidelines for Selecting Contact Protection Circuits1 Proper selection is critical as the use of a contact protection device can extend contact life When mounting the protection device always locate it near the immediate area of the load or contact Typically you should mount a protective device within 18 in of the load or contact Typically contact protection circuits are provided for an overview but you should thoroughly examine the circuit you are planning to use For more specific information on any of these circuits contact the Technical Services Department at American Zettler Inc Diode and Zener Diode Circuit 1 This section has been reprinted with permission from American Zettler Inc Diagram Notes Use in DC applications only Use when diode circuit causes too long release time Use zener diode with zener voltage about equal to power supply voltage Load Nationa
10. stallation category II EMC Directive Immunity EN 50082 1 1994 Emissions EN 55011 1991 Group I Class A at 10 m Mechanical Dimensions Figure 6 shows the mechanical dimensions of the FP RLY 420 installed onto a terminal base Dimensions are given in inches millimeters Figure 6 Mechanical Dimensions 4 31 109 5 3 60 91 44 4 22 107 19
11. te the power consumption First refer to the specifications section in the user manual for your network FP RLY 420 2 www natinst com module The maximum number of terminal bases per bank multiplied by 1 watt is the total power the network module can supply For example an FP 1000 or FP 1001 can support nine terminal bases 9 1 W 9 W Next refer to the specifications section in the operating instructions for the I O modules Use the Power from Network Module specification For example a bank of modules consisting of four FP RLY 420 and five FP DI 301 modules requires a total of 8 4 W from the FieldPoint network module 4 1 7 W 5 0 325 W 8 4 W This power requirement is less than the 9 W maximum and is therefore acceptable Installation The FP RLY 420 mounts on a FieldPoint terminal base FP TB xx unit The hot plug and play operation of the FP RLY 420 allows you to install it onto a powered terminal base without disturbing the operation of other modules or terminal bases The FP RLY 420 receives operating power from the terminal base To install the FP RLY 420 refer to Figure 1 and follow these steps 1 Slide the terminal base key to either position X used for any module or position 7 used for the FP RLY 420 module 2 Align the FP RLY 420 alignment slots with the guide rails on the terminal base 3 Press firmly to seat the FP RLY 420 on the terminal base The terminal base latch locks the FP RLY 420 into
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