Tjernlund CPC-3 Constant Pressure Controller Startup Manual 8504125 - Manual (Page 13)

TESTING THE OPERATION OF THE SYSTEM COMPONENTS
TEST RUN SET UP
Test run can be used to test several aspects of the Inducer / C.A. Blower. While in Test Run mode, the communication between the
CPC-3 control and the VFD can be confirmed, a response from the pressure transducer can be confirmed and the Inducer / C.A.
Blower rotation can be checked and reversed if necessary. Test Run can not be operational while a heater call is recognized by the
CPC-3 control. To operate Test Run, make sure all interlocked heater calls have been removed or refer to the SET STAGES, page 15
to lock out heater calls from being processed.
Test Run is a manually driven test where the user adjusts the speed of the Inducer / C.A. Blower. In order to perform Test Run, the
Key Pad must be unlocked and the Set Up menu for Draft or Combustion Air must be open. Press the INCREASE key until "TEST
RUN OFF" appears in the bottom line of the display. To activate test run, press the ENTER key. Note that the Test Run message
changed to "TEST RUN ON". The factory default setting for test run is 0%. Using the INCREASE key, adjust the Test Run percentage
to 50%.
Press the SET UP key under the Draft or Combustion Air side of the CPC-3 keypad to open SET UP menu.
Press the INCREASE key until "TEST RUN OFF" appears in the bottom line of the display.
Press the ENTER key to change display to "TEST RUN ON".
Press the INCREASE key, adjust the Test Run percentage to 50%.
VFD RESPONSE
With the control in Test Run and operating at 50%, the VFD should be displaying an output frequency and the Inducer / C.A. Blower
should be running. If no response from the VFD or the Inducer / C.A. Blower is realized, verify that the VFD ACTIVATED LED is solid
Green, the VFD has not faulted (solid red ALARM LED if faulted) and that the VFD has supply power at the correct voltage.
PRESSURE RESPONSE
While in Test Run, the Actual Pressure displayed on 3rd column of CPC-3 should be a negative pressure. Increasing the Test Run %
should increase this negative value. Decreasing the Test Run % should decrease the negative. If the pressure does not change,
check the wiring between the control and the pressure transducer, verify the transducer is pneumatically connected to the vent pipe
manifold and the front fitting on the transducer, and check to make sure the pressure transducer is operating correctly.
CHECKING ROTATION
While in Test Run and operating at 50%, record the Actual Pressure displayed on the top line of
the display_______. Press the ENTER key to shut off the Test Run option and wait 60 seconds.
Open the door to the CPC-3 control and reference the 2 dip switches under the Inducer or
Combustion Air terminal blocks at the top of the circuit board. These switches are used to reverse
the rotation of the Inducer / C.A. Blower. Switch both switches on the appropriate Inducer or
Combustion Air side to the opposite position they are currently in. Close the cover to the control
and activate Test Run again by pressing the ENTER key. Remember that no heater can be calling
for heat while performing this test. Adjust the Inducer / C.A. Blower speed to 50% again and record
the Actual Pressure displayed_______. The test that resulted in the greatest negative pressure is
the correct rotation. If the second half of the test resulted in a lower negative pressure the rotation
will need to be reversed to the original condition. Press ENTER to shut off the Test Run, wait 60
seconds, and reverse the 2 dip switch settings.
CAUTION: Systems that use multiple VFD's and/or multiple Inducers / C.A. Blowers will need to
visually verify each fan’s rotation. Changing the rotation as described above will change the rota-
tion of all connected VFD's and fans. In multiple configurations, some rotations may be correct
while others may not. Switch any 2 of the 3 motor leads of the offending Inducer / C.A. Blower to
change the direction of its rotation. VSAD Series impellers must rotate counter-clockwise as
viewed through the discharge grill. VSUB Series impellers must rotate counter-clockwise as viewed
from the end bell/cooling fan of the motor. Failure to insure correct rotation may result in higher
power usage and significantly reduced inducer/blower performance.
Press the ENTER key to shut off the Test Run option and wait 60 seconds.
Change rotation dip switches as described above.
Press ENTER key to activate new Test Run, press Increase key to adjust Inducer / C.A. Blower
speed to 50% and record the Actual Pressure as displayed on the top line of the display.
The test that resulted in the greatest negative pressure is the correct rotation. If the second half of the test resulted in a lower nega-
tive pressure the rotation will need to be reversed to the original condition by changing the dip switches to the opposite positions.
ADJUSTING DRAFT
Reference the heater manufacturer's instructions for its specified draft range and for where the draft should be sampled. In general
most heaters will operate efficiently with a draft of -0.02 to -0.05" w.c. measured in the vent riser between the flue outlet and baromet-
ric draft control (if present). The CPC-3 has a default draft set point of -0.15" w.c. This vent manifold pressure may need to be adjust-
ed up or down to meet the draft requirements of the interlocked heating equipment.
12
VSUB ROTATION 2/27/04
I M P
E L
L
E
R
R
O
T
A
T
I
O
N
VSAD-SERIES ROTATION
VSUB-SERIES ROTATION