42
Entek IRD 6666 and 6667 Protection Monitors
Testing Calibration and Relays
Note:
z
Inputs may be simulated directly at the terminal block as shown or elsewhere. If this
involves application via barriers, ensure that the barrier rating is not accidentally
exceeded.
Calibration and System OK Relay Test for 6666 Monitor
The following steps show you how to test the calibration for input channel 1 for a 6666
monitor. They also test the function of the System OK relay. To test the calibration for input
channels 2 through 6, substitute the correct input channel terminals.
1.
Connect a variable resistance box to the channel 1 input terminals on the terminal
block. Refer to “Signal Inputs for Testing a 6666 Monitor” on page 40 for details.
2.
Connect a multimeter to the 4–20 mA recorder terminals (19 and 20 on the terminal
block for input channel 1).
3.
Set the resistance to 50% of the full scale for input channel 1.
4.
Look at the 6666 front panel display, and note the digital value for input channel 1. The
digital value for input channel 1 should be half of full scale. It might be easiest to press
the DIS button to choose the second display page so you can see every channel at once.
If you use the bar graph, remember that the monitor displays the input channel 1 value
when the indicator (a dash) is over the input channel 1 bar graph.
5.
Look at the multimeter attached to the 4–20 mA recorder terminals. The meter should
read 12 mA ± 4.5% of full scale. 12 mA is half the range between 4 and 20.
6.
Increase the resistance to the resistance high value.
7.
Look at the 6666 front panel display, and note the digital value for channel 1. The
digital value for channel 1 should be the same as the full scale high value.
8.
Look at the multimeter attached to the 4–20 mA recorder terminals. The meter should
read 20 mA ± 4.5%.
9.
Decrease the resistance to the resistance low value.
10. Look at the 6666 front panel display, and note the digital value for channel 1. The
digital value for channel 1 should be the full scale low value.
11. Look at the multimeter attached to the 4–20 mA recorder terminals. The meter should
read 4 mA ± 4.5% of full scale.
12. Test the state of the System OK relay terminals (25 and 26 on the backplane). The
System OK relay is always in failsafe condition, so it should be in the energized (Open)
position.
13. Increase the resistance so that the temperature displayed on the monitor goes above the
TX HI limit (“TX 1-3 and TX 4-6 submenus” on page 21). Check to see that the TX
FAIL message appears on the monitor.
14. Test the state of the System OK relay terminals (25 and 26 on the backplane). The state
should change to Closed when you change the input signal, indicating transducer
failure. Note that the System OK relay is not subject to the GLOBAL alarm delay
(DELAYS submenu, page 25).
50% full scale
resistance high
resistance low
+
2
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