Reznor YDSA Unit Installation Manual - Manual (Page 62)

Form I-Y, P/N 273646R6, Page 62
10. Instructions for Setting Fans to Test and
Balance Airflow
Adjusting the unit fan speeds to achieve the desired air-
flow performance is accomplished on Test Mode screen
E.a.2. Reference the fan airflow tables (APPENDIX,
pages 68 thru 73) for setting the maximum fan speeds.
Using field-supplied tees, connect a manometer to the
appropriate set of pressure tap tubes associated with the
fan -- (Blue and Clear tubes for the Supply Fan) (Yellow
and Clear tubes for the Exhaust Fan).
Measure the actual fan differential pressure and com-
pare it to the appropriate fan airflow table. If an adjust-
ment is required, use the Supply: % and the Exhaust: %
modifiable fields and the up and down keys to increase
or decrease the commanded fan speed until the differen-
tial pressure matches the differential pressure from the
fan airflow table.
If an adjustment is made, the adjusted values will need
to be saved in the TAB Menu. Instructions for saving set-
point values are in Step 17 at the end of the Test Mode
Description instructions.
If the airflow status values are not reading ON, refer to
Form O-Y for instructions.
NOTE: Proof of supply fan airflow is required in order to
complete the Test Mode.
Press the enter key in succession until the cursor
is flashing in the uppermost left hand corner of the
screen and use the down arrow key to navigate to the
next Test Mode Screen E.a.3.
11. From Test Mode Screen E.a.3, press the enter key
until the cursor is flashing on the Comp Capacity:
field. Press the up arrow key to set the Comp
Capacity value to 100%.
Using a digital volt meter, check for the appropriate
line voltage on the load side of the “A” circuit
compressor contactor to verify that it has energized,
and visibly check that the Condenser Section “A” Fan
is operating. When verified, press the down arrow
key to set the Comp Capacity value back to zero.
If no voltage is present or the Condenser Section
“A” Fan is not operable, refer to Form O-Y for
instructions.
12. If the unit is equipped with an optional reheat circuit,
from Test Mode Screen E.a.3, press the enter key
until the cursor is flashing on the Reheat Capacity:
field. Press the up arrow key to set the Comp
Capacity value to 100%.
Using a digital volt meter, check for the appropriate
line voltage on the load side of the reheat circuit
compressor contactor to verify that it has energized.
When verified, press the down arrow key to set the
Reheat Capacity value back to zero.
If no voltage is present, refer to Form O-Y for
instructions.
Press the enter key in succession until the cursor
is flashing in the uppermost left hand corner of the
screen and use the down arrow key to navigate to the
next Test Mode Screen E.a.4.
13. From Test Mode Screen E.a.4, press the enter key
until the cursor is flashing on the Stage 2: field.
Press the up arrow key to set the Stage 2 value to
ON.
Using a digital volt meter, check for the appropriate
line voltage on the load side of the Stage 2 contactor
to verify that it has energized and visibly check that
the Condenser Section “B” Fan is operating. Once
verified, press the down arrow key to set the Stage 2
value back to OFF.
If no voltage is present, or the Condenser Section
“B” Fan is not operable, refer to Form O-Y for
instructions.
Depending upon configuration, the unit may be
equipped with up to 4 stages of cooling. If applicable,
perform the same procedure for the compressors
associated with Stages 3 and 4.
Press the enter key in succession until the cursor
is flashing in the uppermost left hand corner of the
screen and use the down arrow key to navigate to
the next Test Mode Screen E.a.5.
10.0 Commissioning and Startup (cont’d)
10.3 Unit Test Mode and Setting Fan CFM (cont’d)
Test Mode Detailed Description (cont’d)