HIEE300661R0001输出卡件
电压不会影响自动化功能。o当连接自动化设备的输入和输出时，必须采取措施防止在信号线断线的情况下出现未定义状态。PACSystems*RX3i系统手册附录GFK-2314T 2019年9月计算散热量867计算散热量本节介绍如何计算PACSystems RX3i设备的总散热量。PACSystems RX3i设备必须安装在保护外壳中。外壳必须能够适当地消散安装在内部的所有设备产生的热量。这包括模块、离散输出设备和离散输入设备。每个设备制造商都会发布这些值。如果设备没有精确的值，您可以通过获取类似设备的值来进行近似估计。B-1模块散热对于除电源外的每个背板和模块（单独讨论），请从第4.2节模块负载要求表中查找功率（瓦特）。如果模块使用多个电压类型（例如3.3V和24V继电器），请查找其总功率需求。然后，将机柜中所有模块的散热值相加。示例：负载要求表显示，12插槽通用背板IC695CHS012消耗：3.3Vdc电源1.98瓦+5Vdc电源1.20瓦=背板IC695CHS012 B-2电源总散热3.18瓦总散热通常，电源效率为66%。电源每向PLC输送2瓦特的功率，就会以热量的形式消耗大约1瓦特的功率。找到由上述电源提供服务的背板中所有模块的总功率需求后，将总功率除以2，以找到电源消耗值。请勿使用电源的额定功率（例如30 W）进行计算，因为应用程序可能不会使用电源的全部容量。如果正在使用扩展电源上的+24V直流输出，请计算所消耗的功率，将该值除以2，然后将其添加到电源的总数中。PACSystems*RX3i系统手册附录GFK-2314T 2019年9月电缆屏蔽夹紧组件868 17.2.3.16离散输出模块的散热除了上述模块功率计算外，离散固态输出模块还需要对其输出电路进行计算，该输出电路由另一电源供电。（继电器输出模块不需要此计算。）要计算输出电路功耗，请执行以下操作：▪ 在模块的规格表中，查找输出电压降的值。▪ 使用制造商的文档或其他参考信息，查找连接到模块输出点的每个设备（如继电器、指示灯、电磁阀等）所需的电流值。根据每个设备在应用中的预期用途，估计其“按时”百分比。▪ 将输出电压降乘以电流值乘以估计的持续时间百分比，得出该输出的平均功耗。对模块上的所有输出重复这些步骤，然后对背板中的所有离散输出模块重复这些步骤。示例：IC694MDL340 16点离散120 Vac输出模块的规格表中列出了其输出电压降：最大1.5 V将该值用于模块的所有计算。在此示例中，两个输出点驱动控制液压缸前进和后退行程的电磁阀。电磁阀制造商的数据表显示，每个电磁阀的电流为1.0安培。机器循环时，油缸每60秒前进和缩回一次。前进需要6秒，后退需要6秒。因为油缸前进和缩回所需的时间相等，所以两个电磁阀打开的时间长度相等：每60秒中有6秒，占时间的10%。因此，由于两个螺线管具有相等的电流消耗和接通时间，因此可以对两个输出应用一个计算。使用公式平均功耗=电压降x电流消耗（安培）x百分比（以十进制表示）
voltages from affecting automation functions. o When interfacing the inputs and outputs of the automation equipment, measures must be taken to prevent an undefined state from being assumed in the case of a wire break in the signal lines. PACSystems* RX3i System Manual Appendix GFK-2314T Sept. 2019 Calculating Heat Dissipation 867 Calculating Heat Dissipation This section explains how to find the total heat dissipation of PACSystems RX3i equipment. PACSystems RX3i equipment must be mounted in a protective enclosure. The enclosure must be able to properly dissipate the heat produced by all the devices mounted inside. This includes the modules, discrete output devices, and discrete input devices. Each device manufacturer publishes these values. If an exact value is not available for a device, you can make a close estimate by obtaining the value for a similar device. B-1 Module Heat Dissipation For each backplane and module except power supplies (discussed separately), look up the power in Watts from the table of Module Load Requirements, Section 4.2. If the module uses more than one voltage type (for example, 3.3V and 24V relay), find its total power requirement. Then, add together the heat dissipation values for all the modules in the enclosure. Example: The Load Requirements table shows that the 12-Slot Universal Backplane IC695CHS012 draws: 1.98 Watts from the 3.3Vdc supply +1.20 Watts from the 5Vdc supply =3.18 Watts total heat dissipation of backplane IC695CHS012 B-2 Power Supply Heat Dissipation In general, power supplies are 66% efficient. The power supply dissipates approximately 1 Watt of power in the form of heat for every 2 Watts of power it delivers to the PLC. After finding the total power requirement for all of the modules in the backplane served by a power supply above, divide the total by 2 to find the power supply dissipation value. Do not use the rating of the power supply (such as 30 W) for this calculation because the application may not use the full capacity of the power supply. If the +24Vdc output on an Expansion Power Supply is being used, calculate the power drawn, divide the value by 2, and add it to the total for the power supply. PACSystems* RX3i System Manual Appendix GFK-2314T Sept. 2019 Cable Shield Clamping Assembly 868 17.2.3.1.16 Heat Dissipation for Discrete Output Modules In addition to the module power calculations done above, discrete solid-state output modules require a calculation for their output circuits, which are powered from another supply. (This calculation is not required for Relay Output modules.) To calculate output circuit power dissipation: ▪ In the specification table of the module, find the value for Output Voltage Drop. ▪ Using the manufacturer’s documentation or other reference information, find the required current value for each device (such as a relay, pilot light, solenoid, etc.) connected to an output point on the module. Estimate the percent of “on-time” of each device based on its intended use in the application. ▪ Multiply the Output Voltage Drop times the current value times the estimated percent of ontime to arrive at average power dissipation for that output. Repeat these steps for all outputs on the module, and then for all discrete output modules in the backplane. Example: The specifications table for the IC694MDL340 16-Point Discrete 120 Vac Output Module lists its Output Voltage Drop as: 1.5 V maximum Use that value for all of the calculations for the module. In this example, two output points drive solenoids that control the advance and retract travel of a hydraulic cylinder. The solenoid manufacturer’s datasheet shows that each solenoid draws 1.0 Amp. The cylinder advances and retracts once every 60 seconds that the machine is cycling. It takes 6 seconds to advance and 6 seconds to retract. Because the cylinder takes equal time to advance and retract, both solenoids are on for equal lengths of time: 6 seconds out of every 60 seconds, which is 10% of the time. Therefore, since both solenoids have equal current draws and on-times, one calculation can be applied to both outputs. Use the formula Average Power Dissipation = Voltage Drop x Current Draw (in Amps) x Percent (expressed as a decimal)
