User's Manual

905U-L Wireless I/O Installation Manual
905U-L Wireless I/O Page 21 of 40
Version 1.9
Installing the power supply
The unit works with a 9-30 VDC 0.6 Amp CSA certified Class 2 power supply. For use in
Class 1 Div 2 explosive areas, the power supply must be approved for Class 1 Div 2 use.
Warning – explosion hazard
Do not disconnect while circuit is live unless area is known to be non-hazardous.
The following table shows the power supply requirements:
Power supply
905U-L-T
905U-L-R
12V
600 mA
250 mA
24V
300 mA
125 mA
The power supply can be a floating supply or negatively grounded.
The transmitter provides a 24V DC regulated supply for analog loop power. The supply is
rated at 35 mA and should ONLY be used for powering analog loops.
To install the power supply:
1. Connect the positive lead to Power Supply Input.
2. Connect the negative lead to Ground.
Note
To ensure internal surge protection works correctly, you must earth each unit using the
Earth terminal.
You should connect the module to the same ground/earth point as the antenna mounting
to avoid differences in earth potential during voltage surges.
Do NOT connect the positive side of the supply to Earth.
3. The following diagram illustrates the connection:
Ground