9
CD-20SFA Sample Probe Controller
Basic CD-20SFA Check-Out
1.
Disconnect the probe from the CD-20SFA.
2.
Disconnect the input power from the CD-20SFA.
3. Connect a push-button switch to 1TB-5 and 1TB-6 on the control card.
4. Reconnect input power to the CD-20SFA.
5. Activate the switch and verify the CD-20SFA output shaft rotates 180 degrees with each pulse. Wait for
the shaft to stop rotating before repeating the switch activation.
Note—Any input pulses that occur when the CD-20SFA is rotating are disregarded by the control logic.
6. Connect the multimeter to 1TB-3 and 1TB-4 on the control card.
7.
Wait for the configured alarm period to expire (factory default period is 5 seconds) and verify that the
alarm relay contact closes.
8.
Activate the push-button switch to send a pulse and verify that the alarm relay contact opens.
9. Repeat steps 7 and 8 as required.
Sample Probe and CD-20SFA Check-Out
1.
Disconnect input power from the CD-20SFA. The push-button switch should still be connected to 1TB-5
and 1TB-6.
2.
Mount the CD-20SFA to the sample probe and hand-tighten the DC-2 coupling.
3. Verify that the product line is full and pressurized.
4. Reconnect input power to the CD-20SFA.
5. Hold a 100-ml graduated beaker (or other applicable measuring device) under the probe’s discharge.
6. Activate the switch repeatedly to collect 10 samples, 1.5 cc each.
Motor Control Assembly
) consists of a control card and power board mounted to a
ring, which in turn, is mounted to the back of the CD-20A gear motor.
Control Card Functions
The CD20-SFA control card performs the following functions:
• Components C7, R12, CR5, and a U4 gate provide a 100-msec power-up reset.
• An alarm delay timer circuit is implemented with U3, C6, C10, R4, R1 and a U4 gate. This circuit is reset
every time a sample is taken and on initial power-up. U3 counts oscillator pulses and de-energizes relay
1CR after counting 2048 clock pulses from U4 pin 6.
• An input filter circuit connected to 1TB-5 buffers incoming pulses from an external flow measuring de
-
vice. The filter has a 2msec time constant, and the input pulse duration must be at least 5 msec to assure a
start pulse output.
