47
IOM 1372
WWW.DAIKINAPPLIED.COM
STARTUP AND MAINTENANCE
Figure 58: Mount in Direction of Flow
It is important that the flow switch be mounted so that the probe
is sufficiently inserted into the fluid stream.
illustrates
the recommended orientation of the sensor. It may not be
mounted directly on top or directly on the bottom of a horizontal
pipe.
NOTICE
DO NOT alter or relocate factory installed flow switch. If issues exist, contact
Chiller Technical Response at [email protected].
Figure 59:
Remote Mounting Guidelines for Flow Switch
If needed, the adapter is threaded into the pipe using pipe
sealant appropriate for the application. The flow sensor is
mounted onto the adapter using silicone grease. Carefully apply
lubricant to the inside threads and O-ring so temperature probe
does not become coated with lubricant. Torque the adapter/
sensor connection to 18.5 ft/lbs.
Wiring
Refer to wiring diagram in the unit control panel.
Either AC or DC is used to power the flow switch. The unit
controller’s digital input is a DC signal which is supplied through
the switch output of the flow switch for flow indication. It is
required that the AC and DC commons of power be separated.
Contact Chiller Technical Response for alternate wiring
scenarios.
Flow Switch Setup
The flow switch comes from the factory set at a default velocity
of 20 cm/s. This value is typically well below the minimum water
flow specified for the unit evaporator and condenser so field
adjustment is required for adequate low flow protection.
shows the calculated gallons per minute (gpm) for Schedule 40
steel pipe for various fluid velocities from
20 cm/s to 300 cm/s. The flow switch has an overall range of
adjustment from 3 cm/s to 300 cm/s.
Step 1:
Adjust flow through the evaporator to the minimum
desired operating gpm. Maintain this flow throughout the setup
procedure.
Step 2:
Once steady state minimum desired operating flow is
obtained, perform the ‘Teach’ function on the flow switch. The
‘Teach’ function is initiated by holding down the minus ‘-’ button
on the face of the flow switch for 15 seconds. During this 15
second period, LEDs ‘0’ and ‘9’ will be lit green. Once the ‘Teach’
function is completed, the outer LEDs will flash green as shown
in
Figure 60: Automatic Teach of Setpoint