RHE28 Installation & Startup Guide – Doc. No. 8.2.1.07 – Ver. 1.31
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Digital inputs can be operated with an active DC signal instead of a switch. The maximum input
voltage must not exceed 30V DC. Note that inputs require a switching current of 0.6mA; the
minimum input voltage for a high reading is 14.4V DC.
3.2.3.4
Analog Input
The RHE28 can be equipped with a 4-20 mA analog input for connecting an external transmitter
(such as a pressure sensor) with a passive 4-20 mA output. The RHE28 transmitter provides
power to the connected devices’ output.
The 4 – 20mA analog input is connected to terminal 60 (positive) and terminal 61 (negative). It is
highly recommended that shielded cable be used and that the shield is connected to terminal 68
(PE) at the transmitter.
The analog input in RHE28 transmitters certified for use with an RHM in a hazardous area includes
certified barrier circuitry for connection with an intrinsically safe device.
The negative (AIG) terminal of the input is internally connected to PE, so it is important to connect
only devices that are floating.
Figure 12: Analog Input
Summary of Contents for RHE28
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