IOM 1281-2 • CENTRIFUGAL WATER CHILLERS 70 www.DaikinApplied.com
Maintenance
In Step 3, the ‘Teach’ function re-adjusted the flow switch set
point (SP) while flow was at the minimum desired operating
flow. The chiller will not operate at this flow because the
flow switch is OPEN after performing the ‘Teach’ function.
The benefit of the ‘Teach’ function is to quickly set the set
point within the desired operating range. Additional ‘manual’
adjustment of set point is required in order to allow for chiller
operation at this minimum flow. The ‘+’ and ‘-’ buttons on the
face of the flow switch allow for the manual adjustment of the
SP. Pressing the ‘+’ button reduces the flow set point while
pressing the ‘-’ button increases the flow set point. Each button
press, ‘+’ or ‘-‘, changes the flow set point by 2.5 cm/s.
Step 4:
Press the ‘+’ button until LED ‘9’ begins to flash, as
shown in
Figure 75
. Opening of flow switch should now occur
at approximately 80% to 90% of minimum flow.
Figure 75: Upper Range of Minimum Flow
Step 5:
Once the SP is set, it is recommended that the
sensor be locked to avoid inadvertent readjustment. This
can be performed by pressing both the ‘+’ and ‘-’ buttons
simultaneously for 10 seconds. The indication goes out
momentarily indicating the unit is locked. To unlock, the same
procedure is performed to toggle to unlocked.
NOTE:
1. The LED window display on flow switch represents
a velocity range of 50 cm/s. The window centers on
the set point (SP). For example, if the SP was set to
200 cm/s, then the LED labeled ‘0’ would represent
a velocity of 180 cm/s when lit and the LED labeled 9
would represent a velocity of 230 cm/s when lit.
2. Each LED represents 5 cm/s, or two presses of the
‘+’ or ‘-’ buttons.
3. When power is initially applied to the flow switch,
all green LEDs light and go out step by step. During
this time, the output is closed. The unit is in the
operating mode.
4. When making manual adjustments to the set point
(SP), if no button is pressed for 2 seconds, the unit
returns to the operating mode with the newly set
value.
Flow below display range:
The SP LED will be lit red and
the leftmost LED will be flashing green. For example, if the SP
was set to 200 cm/s, the flashing labeled ‘0’ would indicate that
the flow was below 180 cm/s. This would be shown if no flow
through chiller or lowered than desired flow.
Figure 76: Display for Flow Below Range
Flow above display range:
The SP LED will be lit amber, all
LEDs to the left and right of the SP LED with be green with the
rightmost LED flashing green. For example, if the SP was set
to 200 cm/s, the flashing LED labeled ‘9’ would indicate that
the flow was above 230 cm/s. This may be a normal display
depending on range by which flow varies through chiller.
Figure 77: Display for Flow Above Range
Service Programs
It is important that an air conditioning system receive adequate
maintenance if the full equipment life and full system benefits
are to be realized.
Maintenance should be an ongoing program from the time the
system is initially started. A full inspection should be made after
3 to 4 weeks of normal operation on a new installation, and on
a regular basis thereafter.
Daikin Applied offers a variety of maintenance services through
the local Daikin Applied service office, its worldwide service
organization, and can tailor these services to suit the needs of
the building owner. Most popular among these services is the
Daikin Applied Comprehensive Maintenance Contract.
For further information concerning the many services available,
contact your local Daikin Applied service office.
