Carrier 16DF013-050 - Manual (Page 43)

Before Starting Machine — Be sure that:
1. Power is on to condensing water and chilled/hot water
pump starters, cooling tower fan, and absorption ma-
chine control panel. Control panel status indicator should
show ‘‘000’’.
2. Cooling tower has proper water level (cooling only).
3. Chilled/hot water circuit is full and valves are open.
4. Cooling water circuit is full and valves open for cooling
operation, or drained for heating operation.
5. Fuel valves are open, fuel supply is available, and there
are no leaks.
6. Air supply for burner is adequate and exhaust damper is
open.
7. Controls and valves are adjusted for either cooling or heat-
ing operation.
Cooling/Heating Operation Changeover (Table 9)
— Switch between cooling and heating cycles by using the
following procedures. This can be done only when the chiller/
heater is off. (See Machine Component Identification,
Fig. 2-4, for valve locations.)
CHANGING FROM COOLING CYCLE TO HEATING
CYCLE
1. Place changeover valves A and B in the FULLY OPEN
position.
2. Drain all water in the cooling water piping.
3. Place the cooling/heating changeover switch (TS3) in the
HEAT position.
4. Start the machine according to Start Machine section
below.
CHANGING FROM HEATING CYCLE TO COOLING
CYCLE
1. Place changeover valves A and B in the FULLY CLOSED
position.
2. Fill the cooling water system and vent air from the
piping.
3. Place cooling/heating changeover switch (TS3) in the COOL
position.
IMPORTANT: Purge noncondensable gases that may
have accumulated in the purge tank prior to each
cooling and heating cycle operation with an auxil-
iary vacuum pump.
Start Machine — If machine has manual auxiliary start,
first energize the auxiliaries (see Machine Controls, Start-
Stop System, page 14).
Now follow one of the 2 procedures described below as
it applies to your machine:
• Start-Up After Limited Shutdown — If machine has been
shut down for less than 3 weeks
• Start-Up After Extended Shutdown — If machine has been
shut down for 3 weeks or more
Heating Start-Up or Cooling Start-Up After Lim-
ited Shutdown —
Place the manual switches in the po-
sitions indicated in Table 8 and depress the Start button. Ma-
chine should start in normal manner.
If, however, machine does not lower leaving chilled water
temperature to design during cooling operation, noncondens-
ables may be present. In this case, take an absorber loss read-
ing (see Maintenance Procedures section, page 46).
If absorber loss is 5° F (2.8° C) or less, the chilled water
temperature should drop to design within a short period as
the automatic purge evacuates the machine. A completely
evacuated machine normally has an absorber loss of 2° F
(1° C) or less.
If absorber loss is greater than 5° F (2.8° C), follow the
procedure for Cooling Start-Up After Extended Shutdown,
below.
Cooling Start-Up After Extended Shutdown-
(More Than 21 Days) —
Start the machine in the nor-
mal manner by placing the manual switches in the positions
indicated in Table 8, and then by depressing the Start
button.
When refrigerant pump starts and solution is warm (strong
solution approximately 100 to 130 F [38 to 55 C]), place
burner control switch in LOW FIRE position.
Determine machine absorber loss (see Maintenance Pro-
cedures). If absorber loss is 5° F (2.8° C) or less, open ca-
pacity control valve by placing burner control switch in AUTO.
position and allow machine to operate. The purge will evacu-
ate the machine to the normal absorber loss of 2° F (1° C)
or less.
If absorber loss is more than 5° F (2.8° C), evacuate ma-
chine to remove noncondensables that can prevent normal
operation (see Maintenance Procedures section). An alter-
native procedure is to limit burner firing rate so that strong
solution temperature remains below 140 F (60 C) while ma-
chine purge removes the noncondensables.
When absorber loss is reduced to 5° F (2.8° C) or less,
place burner control switch in AUTO. position, and allow
purge to establish the normal 2° F (1° C) or less absorber
loss rate.
Start-Up After Below-Freezing Conditions
— Refill all water circuits if previously drained. Then
follow procedure for Cooling Start-Up After Extended
Shutdown.
Remove solution from the refrigerant circuit by following
the procedure, Removing Lithium Bromide from Refriger-
ant, in the Maintenance Procedures section, page 49.
Operation Check — The normal operation is shown in
Fig. 32. Also note the following:
1. Check the combustion of the burner through the flame
sight glass. The flame should be stable with no abnormal
combustion noise.
2. There should be no safety device indications on the con-
trol panel status indictor.
3. All pumps should be operating normally. (Check for ab-
normal sounds.)
4. The refrigerant pump should start within 5 minutes after
the chiller-heater is started. (The refrigerant pump is stopped
in heating cycle.)
5. The status indicator shows ‘‘CPF’’, ‘‘CPO’’, or ‘‘HPO’’.
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