Technical data

16
Design set point adjustment (three-step thermostat)
Legend:
A - Differential between stages
B - Differential on one contact
R, Y, B - Thermostat contact reference
O - Open contact
F - Closed contact
Set point adjustment
When the unit is ready for operation, insert a small screwdriver
in the adjusting slot to turn the dial (the dial may also be turned
by hand).
Rotate the screwdriver, until the design set point for the
installation appears directly under the pointer. Insert a
thermometer in the return water connection and allow the unit
to run through a complete cycle.
When switch No. 1 opens, the last capacity step appears
directly under the pointer. Read the temperature. If it is not the
same as the dial reading, it can be compensated by shifting the
control point slightly.
NOTE: Do not force the dial past the stop. This could cause
loss of the control point and damage the instrument.
Set point adjustment
RY3
RB3
RY2
RB2
RY1
RB1
RY3
RB3
RY2
RB2
RY1
RB1
0
F
0
F
0
F
F
0
F
0
F
0
A
B
SET POINT
TEMPERATURE
RISE
TEMPERATURE
DROP
CALIBRATED DIAL
SET POINTS
ADJUSTING SLOT
POINTER
STOP
• Check that oil is visible in each compressor sight glass to
between 1/8 and 3/8 of the total glass depth (check for all
compressors).
• Confirm that there are no refrigerant leaks.
• Confirm that the installation is correct and check the
secure positioning of all control sensors.
• Confirm that discharge muffler securing bands and
discharge line connections are tight.
• Check that all electrical connections are secure.
Checks before start-up at the optional hydronic kit
IMPORTANT:
• The safety valve installed in the Hydroflow module is
activated at 370 kPa, during charging. Please ensure that
this pressure is not exceeded.
• The nitrogen pressure of the expansion tank is controlled
to 100 kPa above the static pressure of the installation.
• Using the pump pressure gauge and the curves for the
available static pressure of the pump, verify the water
flow for the installation.
Actual start-up
IMPORTANT:
• Commissioning and start-up of the chiller must be
supervised by a qualified refrigeration engineer.
• Start-up and operating tests must be carried out with a
thermal load applied and water circulating in the
evaporator.
• All set point adjustments and control tests must be carried
out before the unit is started up.
• Please refer to the controls manual for the unit.
Electromechanical control
Multi-step thermostat
This consists of a series of load switches actuated by the
pressure developed inside a temperature sensing bulb, installed
in the cooler inlet.
Before replacing the bulb, half fill the well with a heat
conducting sealing compound. Replace the sensor in the well
recess. The thermostat is factory-set to control from the return
water temperature through a cooling range of 5.6 K.
The sequence switches are factory-calibrated and sealed
and should not need any field calibration. One step on sizes
009-013, two steps on sizes 015-020 and three steps on sizes
025, 030 and 035 are available.
WARNING: Alteration of factory settings other than the design
set point, without the manufacturer's authorization, may void
the warranty.
If a different return water range or leaving water control is
specified, or if brine is to be used, the controller must be
changed. Consult your local Carrier representative for the
proper control.
Units with PRO-DIALOG control
Please refer to the installation, operation and maintenance
instructions for the PRO-DIALOG control (order No. 13163-76).