Carrier 16DF013-050 - Manual (Page 40)

10. Place the burner on full AUTO. control and provide enough
load on machine for continued operation at high fire for
3 to 5 days. Periodically check the weak solution con-
centration (see Solution or Refrigerant Sampling in Main-
tenance Procedures section, page 48) to be sure the strong
solution is not approaching crystallization. It may be nec-
essary to leave the TS2 dilution valve on MANUAL dur-
ing cooling operation if there is not enough load for
continued burner operation at high fire.
Add Octyl Alcohol — When the initial start-up is per-
formed during cooling operation, add the amount of initial
octyl alcohol specified in Table 14 before normal operation
is started. When starting during heating operation, do not
add the initial octyl alcohol charge until the machine is switched
over to cooling.
Add the alcohol through the high-temperature generator
drain valve according to the instructions under Adding Oc-
tyl Alcohol in the Maintenance Procedures section page 49,
do not allow air to be drawn into the machine.
Table 14 —Octyl Alcohol Initial Charge
16DF
OCTYL ALCOHOL
Gal. L
013,015 2 7.6
018,020 2 7.6
023,025 2 7.6
028,032 3 11.4
036,040 3 11.4
045,050 4 15.2
Initial Start Operation — When the initial combus-
tion run-in period has been completed, normal operation may
begin. Start machine following the procedures described in
Operating Instructions section for Start-Up After Extended
Shutdown, page 43. Evacuate the machine to remove non-
condensables if the absorber loss is above 5° F (2.8° C). If
the absorber loss is below 5° F (2.8° C), the machine may
be placed in AUTO. control for normal operation.
Capacity Control Adjustments — The control set
points for the leaving chilled water and hot water tempera-
tures are factory set but may be adjusted, if necessary, ac-
cording to the Automatic Capacity Control explanations in
the Machine Controls section, page 31.
Refrigerant Charge Final Adjustment — The re-
frigerant charge final adjustment must be made to ensure that
normal solution concentrations can be achieved for full ca-
pacity and that refrigerant overflow will occur with exces-
sive solution concentrations to prevent crystallization. The
adjustment should be made only when:
1. machine is operating on cooling with stable temperatures
at 40 to 100% of full load;
2. absorber loss is 3° F (1.7° C) or less; and,
3. refrigerant specific gravity is 1.02 or less.
Proceed as follows:
1. Remove a solution sample from the solution pump
service valve and measure the specific gravity and
temperature.
2. Locate the intersection point of the specific gravity and
temperature values on equilibrium diagram (Fig. 30A or
30B). Read down from this point to the solution concen-
tration scale to determine the percent lithium bromide by
weight in the weak solution.
3. Determine the approximate percent of full load on the ma-
chine by comparison of chilled water temperature spread
and flow in relation to design. Enter Table 15 at this per-
cent load and find the corresponding weak solution con-
centration required for refrigerant charge adjustment un-
der nominal conditions.
4. Adjust machine operating conditions until machine op-
erates with stable temperatures at either of the weak so-
lution concentrations (±0.1%) listed in Table 15 under the
selected percent load.
To increase the concentration:
a. Increase the load.
b. Lower
chilled water temperature (set point
adjustment)
c. Raise condensing water temperature (or reduce con-
densing water flow).
After adjusting conditions, repeat Steps 1 and 2 to verify
solution concentration.
5. Check the relative temperature of the evaporator refrig-
erant overflow pipe.
a. If it is cold (about the same temperature as the refrig-
erant pump discharge), the machine may have too much
refrigerant. Remove about 3.8 L (1 gal.) of water through
the refrigerant pump discharge valve. Continue to re-
move water in 3.8 L (1 gal.) increments until the over-
flow stops. Wait about 10 minutes between reductions
to allow for temperature changes to be noted. Refrig-
erant overflow will change machine operating condi-
tions, so repeat Steps 1 through 4 periodically.
b. If it is warm (close to ambient temperatures, the ma-
chine may have too little refrigerant. Add about
3.8 L (1 gal.) of water through the refrigerant pump
service valve. Do not allow air to be drawn into the
machine. Continue to add water in 3.8 L (1 gal.) in-
crements until overflow just starts. Wait about 10 min-
utes between additions to allow for temperature changes
to be noted.
Table 15 — Weak Solution Concentration For
Refrigerant Charge Adjustment
PERCENT LOAD
ON MACHINE
100 90 80 70 60 50 40
WEAK SOLUTION
CONCENTRATION
60.0 60.4 60.8 61.2 61.6 61.9 61.2
Check Machine Shutdown — Press the Stop button
to verify normal shutdown sequencing. The burner should
drive to low fire and then stop. The machine will go through
a dilution shutdown period and the pumps will stop accord-
ing to the Typical Control Sequence for Normal Cooling Stop
or Normal Heating Stop described in the Machine Controls
section, page 28.
OPERATING INSTRUCTIONS
Operator Duties
1. Become familiar with absorption machine and related equip-
ment before operating. See Introduction and Machine De-
scription sections, page 3.
2. Start and stop machine as required.
3. Inspect equipment; make routine adjustments; maintain
machine vacuum and proper refrigerant level; exhaust purge
as required; check and maintain combustion system.
4. Keep log of operating conditions and recognize abnor-
mal readings.
5. Protect system against damage during shutdown.
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