Fluid Components International FLT93 Nuclear - Manual (Page 37)

FLT ® Series FlexSwitch TM OPERATION
Fluid Components International LLC 37
Fail Safe Alarm Setting
These procedures set the second relay to detect component failure (fail-safe).
Low Flow Alarm Settings
For the low fl ow fail safe setup the following jumpers are to be installed: J18, J20, J23, J24, J27.
The following information is assumed:
Relay is de-energized in the ALARM condition.
Alarm 1 set point is adjusted for desired low fl ow alarm velocity or signal.
Alarm 2 set point is adjusted slightly below minimum signal output (over range fl ow).
High Flow Alarm Settings
For the high fl ow fail safe setup the following jumpers are to be installed: J18, J20, J23, J25, J26.
The following information is assumed:
Relay is de-energized in the ALARM condition.
Alarm 1 set point is adjusted for desired high fl ow alarm velocity or signal.
Alarm 2 set point is adjusted above maximum signal output (under range fl ow not to exceed 7.0 volts).
Figure 3-5. Low Flow Fail Safe Alarm
0.5
0 20 10 30 50 40 60
1.0
0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
WHEN ALARM 1 DETECTS HIGH FLOW
THERE IS A POSSIBLE SHORTED
ACTIVE RTD OR OPEN REFERENCE
RTD
ALARM 2 DETECTS A POSSIBLE
OPEN ACTIVE RTD OR SHORTED
REFERENCE RTD
SIGNAL
OUTPUT
AIR FLOW RATE
SET POINT 2
SET POINT 1
DE-ENERGIZED
DE-ENERGIZED
ENERGIZED
ENERGIZED
C00535-1-2
A POWER FAILURE IS DETECTED IF
BOTH RELAYS ARE DE-ENERGIZED
Figure 3-6. High Flow Fail Safe Alarm
0.5
0 20 10 30 50 40 60
1.0
0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
WHEN ALARM 1 DETECTS LOW FLOW
THERE IS A POSSIBLE OPEN ACTIVE
RTD OR SHORTED REFERENCE RTD
WHEN ALARM 2 DETECTS OVER
RANGE FLOW, THERE IS A POSSIBLE
HEATER FAILURE, SHORTED ACTIVE
RTD OR OPEN REFERENCE RTD
SIGNAL
OUTPUT
AIR FLOW RATE
SET POINT 1
SET POINT 2
DE-ENERGIZED
DE-ENERGIZED
ENERGIZED
ENERGIZED
C00534-1-2
A POWER FAILURE IS DETECTED IF
BOTH RELAYS ARE DE-ENERGIZED