Motorola V186 User Manual - Page 71
RTU I/O Expansion - Power Considerations
View all Motorola V186 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 71 highlights
RTU I/O Expansion - Power Considerations When planning a co-located multi-I/O expansion frame configuration (where all frames are located in the same enclosure or 19" rack), it is possible to cascade the power supplies of the expansion frames to the power supply in the main frame. In the system design stage (before ordering), it is critical to calculate the maximal accumulated power consumption from the main frame power supply (or from a power supply located on an expansion frame which is not an expansion power supply) to make sure it is not overloaded. It is also critical to consider the voltage drop due to the cascading of power supplies. Power Consumption The first step in the design is to calculate the number of expansion frames that can be cascaded per the power supply specifications. The following power consumption information should be accumulated for the RTU: Maximal accumulated power consumption of the main frame (CPU, I/O modules, 24 V floating power supplies on modules, radio, etc.) Maximal accumulated power consumption of the each expansion frame (expansion module, I/O modules, floating power supplies on modules) Note: The power consumption information is described in the ACE3600 Owner's Manual and in this document in Appendix C: ACE3600 Maximum Power Ratings. The accumulated power consumption from the main power supply (located in the main frame) should not exceed its maximum current output specifications. Consider the following example: An expanded RTU requires five expansion frames. The accumulated power consumption of all frames exceeds the main power supply specifications. The accumulated power consumption of the main frame and the four first frames exceeds the main power supply specifications. The accumulated power consumption of the main frame and the three first frames does not exceed the main power supply specifications. This means that from the power consumption perspective the first three expansion frames can be cascaded to the power supply in the main frame, the expansion power supply on the fourth expansion frame should be replaced with AC or DC power supply option and the fifth expansion power supply can be cascaded to this added power supply. Voltage Drop The second step is to calculate the number of expansion power supplies that can be cascaded per the allowable input voltage to the expansion power supply. 67