User's Manual

14
The UVU-140-A or UVU-140-AR current output will change with the amount of ultraviolet light being
detected (see Table 4).
2. Turn off the UV test lamp.
3. Repeat steps 1 & 2 for all detectors in the system.
4. After all detectors have been checked, return the system to the normal operating mode.
5. Restore power to output loads or remove any mechanical blocking devices.
CHAPTER 4 NORMAL OPERATION
Normal Operation
In normal operation the detector outputs 4mA.
Fire Condition
In a fire condition the detector outputs 20mA.
Current & Relay Output Conditions
The 4-20mA DC current output transmits system information to other devices. The current output can only be
wired for non-isolated operation. The current output can have a maximum external loop resistance of 600 Ohms at
10.5 to 32Vdc. Table 4 shows the current output levels for various conditions.
Table 4 - Current & Relay Output Conditions
Current Output Situation
0mA Shorted signal output or loss of power
1mA Internal power fault or system power out of range. Fault relay
activated on UVU-140-AR
2mA Automatic or manual vi test failure. Fault relay activated on
UVU-140-AR
4mA Normal operation
6mA Background UV source
10mA Manual vi test (adequate) clean all optical surfaces.
11mA Manual vi test (good) optical surfaces are moderately clean
12mA Manual vi test (excellent) all optical surfaces are clean
16mA Instant alarm
20mA Fire condition detected. Fire relay activated on
UVU-140-AR