Section 3: Series 3700A cards power usage Series 3700A Switch and Control Cards Reference Manual3-2 3700AS-909-01 Rev. B / December 2011Power budgeting and calculationIndividual relay power consumption generally depends on the type of relay. Latching-type relaysconsume power only briefly in order to open or close. These types of relays are not of concern forpower budgeting purposes. Nonlatching types of relays continuously consume power in order tomaintain their state. These types of relays must be considered for power budgeting purposes.Another power consideration is the fact that each plug-in card uses system power in order to operate.This continuous power draw is known as quiescent power. Quiescent power directly takes away fromthe power that is available to operate relays. So it must also be taken into account when budgeting forpower consumption.The following table shows the power consumption of channel and backplane relays for various Series3700A plug-in cards. The quiescent power is also shown. For latching-type relays NA is used.Model Quiescent power (milliwatts) Channel relay powerconsumption (milliwatts) eachBackplane relay powerconsumption (milliwatts)each3720 975 NA 1003721 1350 NA 1003722 475 NA 1003723 700 100 (2-Pole) 10050 (1-Pole) 1003724 1150 20 1003730 780 NA 1003731 780 67 1003732 780 17 1003740 1000 NA (independent) 100200 (high current) 1003750 3300NOTE: The 3300 is reduced whenpower is disabled to each analogoutput channel (820 each) ordisabled to the totalizers (730 for all4; cannot be individually disabled)See Example 5 (on page 3-6),Example 6 (on page 3-7), andExample 7 (on page 3-7).0 each (digital input channel)365 each (digital output channel)470 each (analog output)0 each (totalizers)
