15
51-650 Model 961/962 Echotel SIL Safety Manual -– Loop Version
Step
Proof Test – Echotel Model 962 Loop
Refer to the Model 962 installation and operation manual and the SIL Safety Manual
(note the chart in section 2.5.4.4 of the I & O Manual).
8p5.158
1
Bypass the PLC or take other action to avoid a false trip.
2
Inspect the Unit in detail outside and inside for physical damage or evidence of environmental or
process leaks.
a.) Inspect the exterior of the Unit housing. If there is any evidence of physical damage that may
impact the integrity of the housing and the environmental protection, the unit should be repaired
or replaced.
b.) Inspect the interior of the Unit. Any evidence of moisture, from process or environment, is an
indication of housing damage, and the unit should be repaired or replaced.
3
Observe and record the settings of the HI/LOW and 22/3.6 DIP switches, the LED indicators, Loop
Current and Sensor GAP conditions (WET or DRY).
If the FAULT condition is indicated by loop current and LED indicators all OFF, diagnose the fault and
repair or replace the unit.
Confirm proper operation of the unit: WET/DRY GAP conditions; 8mA LED, 12mA or 16mA LED is
lighted; Loop current = 8mA ±1mA, 12mA ±1mA or 16mA ±1 mA.
a.) Press LOOP TEST push button and confirm change; 8mA >> 12mA, 12mA >> 16mA or
16mA >> 8mA. Release the button and unit returns to proper operation.
b.) Change HI/LOW DIP switch position. Confirm both LED & Loop Current change state;
8mA >> 16mA or 16mA >> 8mA. Note that 12mA will stay at 12mA with the switch change.
Observe the time delay from change of DIP switch until LED and Loop current change. Delay is
set by Time Delay Pot, so delay may be as long as 12 seconds. Press LOOP TEST push button
and confirm change; 8mA >> 12mA, 12mA >> 16mA or 16mA >> 8mA.
Release the button and unit returns to proper operation. Change HI/LOW DIP switch back to
original setting and confirm proper operation, after the delay.
c.) Press FAULT TEST push button and confirm: all LEDs go OFF; Loop current
≥
22mA or
≤
3.6mA
based on 22/3.6 switch. Release button.
d.) Change the 22/3.6 DIP switch position. Press FAULT TEST push button and confirm: all LEDs
go OFF; Loop current
≥
22mA or
≤
3.6mA as expected. Release push button. Return 22/3.6
switch to original setting.
e.) Adjust the Time Delay Pot to maximum delay, fully clock-wise up to 20 turns. Change HI/LOW
DIP switch position and observe the time delay from change of DIP switch until LED and Loop
current change. Confirm delay
≥
10 seconds. Change HI/LOW DIP switch back to original set-
ting and confirm
≥
10 seconds delay. Adjust the Time Delay Pot to minimum delay, fully counter-
clock-wise ~20 turns. Change HI/LOW DIP switch position and observe the time delay. Confirm
delay
≤
1 seconds. Change HI/LOW DIP switch back to original setting and confirm minimum
delay.
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