TM 5-3895-374-24-1
GP470FA
EXAMPLE 2:
Same as example 1 except Proportional Band - 80% (0.80)
DEV
=
0.10" (same as example 1)
0.10
Output
=
0.80 x 1.0
=
0.125 Displayed as OUT 62.5 (50 + 12.5)
(output decreases due to Pb increase)
On Time
=
: 5 x 0.125 :
=
0.625 seconds (on time decreases)
Relay 1 will be on for 0.625 seconds and off for 4.375 seconds.
EXAMPLE 3:
Same as example 1 except Cycle Time - 10 seconds.
DEV
=
0.10" (same as example 1)
Output
=
0.20 (same as example 1)
On Time
=
: 10 x 0.20 :
=
2.0 seconds (on time increases due to cycle time increase)
Relay 1 will be on for 2 seconds and off for 8 seconds.
EXAMPLE 4:
Same as example 1 except Dryer Draft - -0.15" wc.
Since the measured draft is now less than the setpoint the deviation is a negative value and the controller will energize
Relay 2 in order to Open the exhaust damper. The on time of relay 2 is calculated as follows:
DEV
=
(-0.20") - (-0.15")
=
-0.05"
=
-0.05"
Output
=
0.50 x 1.0
=
-0.10 Displayed as OUT 40.0 (50 - 10)
On Time
=
: 5 x -0.10 :
=
0.5 seconds
Relay 2 will be on for 0.5 seconds and off for 4.5 seconds.
(page 3-50)
