National Instruments FP-RLY-420 - Manuals

Page 2 - Installation; Slide the terminal base key to either position X (used for any

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 instr...

Page 3 - Field Wiring; nel; COM

© 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...

Page 4 - Figures 2a and 2b show examples of basic wiring connections.; Relay Output Circuit; In the ON state, there is an effective resistance of 100 m

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....

Page 5 - Figure 3 shows the diagram of one channel’s relay output circuit.; Contact Protection for Inductive Loads; Guidelines for Selecting Contact Protection Circuits

© 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 V...

Page 6 - Diode and Zener Diode Circuit; Diagram

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 pr...

Page 7 - Diode Circuit

© National 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...

Page 8 - Status Indicators; Type of 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 ...

Page 9 - Isolation and Safety Guidelines; Caution; Read the following information before

© 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 initia...

Page 10 - Specifications; Input Characteristics; Nonlatching; Note; Expected Life

FP-RLY-420 10 www.natinst.com • Do not share the external supply voltages (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 m...

Page 11 - Maximum switching frequency; Physical; EMC Directive

© National Instruments Corp. 11 FP-RLY-420 Maximum switching frequency Mechanical ................................. 20 operations per secondElectrical..................................... 1 operation per second at maximum load Relays operate time........................... 6 ms typical, 8 ms max. Re...