Carrier 16JA User Manual
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Hermetic Absorption Liquid Chillers
Carrier
MACHINE OPERATION
MACHINE START-STOP SYSTEMS
General - The exact start-stop system for a given
machine is established by the customer. Systems
can vary from one installation to another. These
systems and procedures are meant for general
guidelines only.
The three most common types of systems are
given below. Review these systems and decide
which applies to your machine. Then follow the
start-stop procedure given.
NOTE: If machine has been shut down for more
than 2 days, follow procedures under Start-Up
After Limited Shutdown or Start-Up After
Extended Shutdown. In all cases below, when
machine starts, the white run light will en
ergize. When the machine stops, the light will
go out after automatic dilution.
Automatic Start-Stop System - Starting and stop
ping with this system is accomplished by an
automatic controller such as a thermostat or
time clock, etc. Also, an AUTO-MANUAL switch
is provided so the machine can be started bypressing machine START button with switch in
MANUAL position. All auxiliary equipment is
tied in with the machine control circuit and will
start when the machine starts. If automatic time
delay relays are provided, the machine will start
after a preselected time interval.
The operating engineer must make periodic
checks to ensure that the machine with auxiliary
equipment is operating satisfactorily.
PROCEDURES
1. Place AUTO-MANUAL switch in the AUTOpo-
sition for the machine to start or stop automat
ically. The automatic controller determines
when the machine starts or stops.
2. To start fully automatic machines after limited
or extended shutdown place the AUTO-MANUAL
switch in MANUAL and press the START
button. Then follow start-up procedures for
limited or extended shutdown. Only after man
ual start has been completed should the AUTO
MANUAL switch be placed in AUTO.
NOTE: When the machine shuts down either
automatically or manually, the refrigerant
and solution pumps will continue to run
until automatic dilution is completed.
Semiautomatic Start-Stop System - All auxiliary
equipment used with this system is tied directly
to the control circuit. It is necessary for the
operating engineer to press the START button
to start the condensing water pump, chilled water
pump, machine pumps, and cooling tower fan
(if used).
PROCEDURES
1. Press STOP button to stop machine.
START button to start machine.
NOTE: On shutdown the machine pumps will
continue to run until automatic dilution
is completed.
Semiautomatic Start-Stop System with Manual
Auxiliaries - All auxiliaries must be started
manually.
PROCEDURES
1. Start chilled water pump.
2. Start condensing water pump.
3. Start cooling tower fan (if used). (This depends
on outside temperature.)
4. Press START button to start machine.
5. To stop machine, press STOP button. Then
stop the following:
a. Cooling tower fan (if used).
b. Condenser water pump.
c. Chilled water pump.
NOTE: The refrigerant and solution
pumps will continue to run until auto
matic dilution is completed.
MACHINE START-UP PROCEDURES
General - Procedures for start-up differ depend
ing on how long the machine has been shut down.
There are two start-up procedures: Start-up
after limited shutdown (3 days to 3 weeks), and
start-up after extended shutdown (over 3 weeks).
Start-Up After Limited Shutdown
PROCEDURES
1. Start the machine as outlined for your system
under Machine Start-Stop Systems.
2. Check the leaving chilled water temperature.
If temperature drops to design, then steps 3
and 4 are not necessary. If the temperature
does not drop to design, noncondensables are
probably present in the machine. Proceed
with steps 3 and 4.
3. Determine the amount of noncondensables by
taking an absorber loss reading (the temper
ature difference between the refrigerant and
solution vapor). To determine absorber loss,
refer to Carrier Standard Service Techniques,
publication SM-16. A machine with absorber
loss of less than 6 F can normally be started
without the machine solution becoming solid
ified. If absorber loss is greater than 6 F,
auxiliary evacuation is recommended. A ma
chine fully evacuated will normally have an
absorber loss of 2 F or less. Instructions
for auxiliary evacuation are in Carrier Stand
ard Service Techniques, publication SM-16.
Press
Carrier Corporation 1968 Printed in U.S.A.
1-68
16JA-1SO
To prevent solidification while purging:
a. Place reclaim switch to MANUAL.
b. Throttle back steam control valve.
(1) Electronic Control - Turn the control
point adjustor up approximately ten
degrees (ten divisions).
(2) Pneumatic Control - Turn the chilled
water thermostat set point up ten
degrees.
4. Evaluate machine tightness with a noncon
densable accumulation rate check. Refer to
Carrier Standard Service Techniques, publica
tion SM-16.
Start-Up After Extended Shutdown - This pro
cedure is critical since accumulated noncon
densables may allow the machine solution to
solidify if the following precautions are not taken,
PROCEDURES
1. Start the machine as outlined for your system
under Machine Start-Up Procedures. Make
sure steam valve is closed. If absorber solu
tion level is high (above 9 in.) and refrigerant
pump is noisy, open steam valve until absorber
level indicator shows approximately 9 in. of
solution, then close steam valve. Place refrig
erant pump switch in ON position.
2. Determine absorber loss by following proce
dures outlined in Carrier Standard Service
Techniques, publication SM-16.
a. If absorber loss is less than 6 F, open
steam valve and allow machine to go into
automatic operation.
b. If absorber loss is 6 F or greater, auxil
iary evacuation is required. Use instruc
tions for auxiliary evacuation provided in
Carrier Standard Service Techniques, pub
lication SM-16.
3. Continue auxiliary evacuation until absorber
loss is less than 6 F. Place machine in auto
matic operation.
4. After auxiliary evacuation, evaluate machine
tightness with a noncondensable accumulation
rate check.
WINTER CONDITIONS
General - At the end of each cooling season when
the machine is no longer required use one of the
following winter shutdown procedures. The choice
depends on whether the machine ambient tempera
ture will be kept above or below freezing.
Shutdown Procedures
BELOW FREEZING
1. Stop machine and wait until automatic dilution
completes and machine pumps stop.
2. Set dilution thermostat to its lowest possible
setting.
3. Connect a hose between solution and refrig
erant pump service valves. Open both valves.
4. Switch refrigerant pump ON-OFF switch to
OFF and solution pump switch to ON.
5. Press START button and allow solution pump
to run for approximately 5 minutes.
NOTE: This procedure contaminates the
refrigerant with lithium bromide solution
lowering the refrigerant freezing point.
6. Press STOP button and reset dilution thermo
stat to 140 F (refer to Checking Dilution Ther
mostat under Maintenance).
7. Drain water from all chilled water, condensing,
steam and condensate circuits. Flush all cir
cuits with ethylene glycol.
ABOVE FREEZING
1. Press STOP button.
2. Allow machine to go thru automatic dilution.
When dilution has completed, machine may
be left in this condition until spring start-up.
Start-Up Procedures
BELOW FREEZING
1. Refill all water circuits that were drained at
shutdown.
2. Follow Start-Up After Extended Shutdown pro
cedures.
3. Reclaim lithium bromide from refrigerant
circuit. Follow Reclaim Solution procedures
given under Maintenance.
4. Restart machine.
ABOVE FREEZING
1. If machine vacuum was broken for maintenance
work, etc., follow auxiliary evacuation pro
cedures outlined in Carrier Standard Service
Techniques, publication SM-16. Then follow
Start-Up After Extended Shutdown procedures.
2. If machine vacuum was not broken, follow
Start-Up After Extended Shutdown procedures.
PURGE OPERATION
General - The 16JA purge unit automatically per
forms the following functions:
1. Removes noncondensables from the machine.
2. Accumulates these noncondensables in the
purge storage chamber where they will not
affect the machine performance.
3. Provides an indication of the degree of air
leakage into the machine.
The 16JA purge unit cannot be used as an auxil
iary evacuation device to evacuate the machine.
When the purge exhaust light (red) is energized
during machine operation, it indicates that the
purge must be manually exhausted. For instruc
tions refer to the instruction sticker located on the
separation chamber (Fig. 1) or use the following
procedure.
CONDENSER PURGE
SUCTION LINE
PURGE EXHAUST
VALVE
INSTRUCTION
STICKER PURGE
PURGE RETURN VALVE
TO GENERATOR OVERFLOW TUBE
SEPARATION
CHAMBER
STORAGE CHAMBER
SUPPLY LINE
service valve. With correct pump rotation, the
gage will indicate a positive reading above at
mospheric pressure. If the pump is solidified,
the gage will indicate atmospheric pressure.
If the casing is partially desolidified and the
pump will not turn, the pressure gage will in
dicate a deep vacuum. Continue to heat the
casing until the pump is desolidified. Desolid
ification of the heat exchanger will take place
automatically once the pump starts functioning.
3. Refer to Troubleshooting Guide for possible
causes of solidification and their correction.
SOLUTION PUMP-
Fig. 1 - Purge Exhaust System
Manual Exhaust Procedures
1. Close purge return valve.
2. Wait 10 minutes for storage chamber to
pressurize.
3. Slowly open purge exhaust valve. If level in
container drops, shut valve and wait 2 minutes.
Reopen valve. If bubbles appear, keep valve
open until bubbles stop and level in container
rises, then close valve.
4. Collect lithium bromide solution to recharge
into machine. Recharging procedures are given
in Carrier Standard Service Techniques, pub
lication SM-16.
SOLUTION DESOLIDIFICATION
General - Should solidification occur, it will occur
usually in the shell side ofthe heat exchanger, pre
venting the strong solution in the generator from
returning to the absorber thru the strong solution
line. However, the strong solution will be returned
to the absorber thru the generator overflow tube
(Fig. 6) thereby desolidifying automatically.
If during a shutdown period solidification has
occurred to the extent that the solution pump will
not rotate and the motor overloads trip put, desolidify by using the following procedure.
PROCEDURE
1. Heat the pump casing and adjacent lines with
steam until the pump will rotate. Be careful
not to allow steam and condensate to enter the
pump motor and controls.
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2. Confirm pump rotation. Rotation of the her
metic pump cannot be viewed directly. Install
a compound pressure gage on the solution pump
MAINTENANCE
INTRODUCTION
General - The following are routine steps nec
essary for normal preventive maintenance on
16JA Hermetic Absorption Liquid Chillers.
To ensure the continued satisfactory perform
ance of the machine, these schedules must be
closely adhered to.
We recommend the suggested steps be per
formed as often as indicated, and that an accurate
log be kept to aid in diagnosing any troubles.
Certain components and operations should be
checked on an individual basis as needed.
EACH MONTH
Reclaim Solution - During normal operation it is
possible that some lithium bromide might carry
over into the refrigerant circuit.
To determine if contamination exists, remove
a refrigerant sample from the machine using
refrigerant and solution sampling procedures out
lined in Carrier Standard Service Techniques,
publication SM-16. Measure the specific gravity
of the sample. If the value exceeds 1,02, the solu
tion must be reclaimed.
RECLAIM PROCEDURE FOR CONTINUOUS OP
ERATION
1. Place reclaim valve switch in MANUAL posi
tion. Wait for approximately 15 minutes. This
causes refrigerant to flow into the solution
circuit where the lithium bromide solution
is reclaimed.
2, Place reclaim switch in AUTO position, de
energizing the refrigerant solenoid valve,
thus stopping refrigerant flow.
RECLAIM PROCEDURE FOR FREQUENT SHUT
DOWN - When the machine is shut down, the re
claim valve will automatically reclaim the lithium
bromide salt solution.
NOTE: If the reclaim solenoid valve does not
energize during the reclaim procedure (aud
ible click, and typical rattling noise of refrig
erant passing thru the valve) contact your
nearest Carrier representative for assistance.
Check Machine Tightness - The most important
maintenance item on the absorption machine is
maintaining vacuum tightness within acceptable
limits. Check machine tightness by determining
the noncondensable accumulation rate. Use pro
cedures given in Carrier Standard Service Tech
niques, publication SM-16.
condenser water temperature. Turn down control
point adjuster below design leaving chilled water
temperature setting. Repeat steps 1 thru 4.
Continual removal of water indicates leakage in
one of the tube bundles. Leak test by using proce
dures outlined in Carrier Standard Service Tech
niques, publication SM-16.
EVERY 2 MONTHS
Check Dilution Thermostat - The dilution thermo
stat should be open when the strong solution drops
to 140 F. If temperature cutout point is not 140 F,
insert screwdriver in slot on face of thermostat
(located on strong solution line) and turn adjust
ment dial until cutout occurs at 140 F.
Check Low-Temperature Cutout - Remove low-
temperature cutout sensing element from sep
arable well in the evaporator shell. Place it in
an ice bath. Low-temperature cutout should trip
at 5 F below design leaving chilled water tem
perature or a minimum of 36 F. The actual cutout
point is the dial setting less 3 F differential. When
the control trips, the machine will shut down
immediately without going thru a dilution cycle.
NOTE: The chilled water pump will continue
to run if hooked up in the standard wiring
arrangement.
EVERY 6 MONTHS
Check Evaporator Water Charge-Check the evap
orator water charge to determine if the reclaim
valve has energized. If valve has energized then
either tube leakage or excess refrigerant is
indicated.
Reclaim should start at full load (corresponds
to approximately 62 percent lithium bromide in
absorber for standard nominal conditions). Check
as follows:
1. Operate machine at full load with design en
tering condensing water and design leaving
chilled water.
2. Remove a sample of evaporator water from
refrigerant pump service valve and check the
specific gravity. If specific gravity is below
1.02 proceed with step 3. If specific gravity
is above 1.02 reclaim solution (see instruc
tions for Reclaim Solution, page 3) until specific
gravity is below this point, then proceed with
step 3.
3. Evaluate absorber loss. Should be 2 F or less.
If more, purge air from machine.
4. Check reclaim line by feel. Listen for refrig
erant flow (audible). If reclaim line is already
cold, with audible refrigerant flow, remove
refrigerant until reclaim valve closes (audible
click) and refrigerant flow ceases.
If machine is operating under light load, it will
be necessary to concentrate the absorber weak
solution to 62 percent. To do this, raise entering
Check Capacity Control Valve - Check to see if
leaving chilled water is being maintained at design
temperature. If not, adjust the electronic or
pneumatic control.
TO ADJUST ELECTRONIC CONTROL
1. Move control point adjuster clockwise to in
crease temperature, or counterclockwise to
decrease temperature. If this fails to bring
leaving chilled water within design temper
ature, perform step 2.
2. Replace vacuum tubes in control motor. Make
sure that new tubes are installed in correct
plugs. If this fails to bring leaving chilled
water within design temperature, proceed
with step 3,
3. Clean relay contacts with stiff paper. If this
fails to correct problem, contact Carrier
immediately.
TO ADJUST PNEUMATIC CONTROL
1. Reset control point setting to design.
2. If above fails to correct problem, contact
Carrier immediately.
Check Cooling Tower Bypass Control - If control
is not maintaining design entering condensing
water temperature, recalibrate the control ther
mostat. For information, contact the valve (or
control) manufacturer.
EVERY YEAR
Check for Absorber and Condenser Scale - Check
absorber and condenser tubes to see if cleaning
is required. Soft scale may be removed with tube
cleaning brushes. When hard scale has formed,
it may be necessary to chemically clean the tubes.
If a scale problem occurs, contact a water treat
ment representative. Annual tube cleaning may
not be required if adequate water treatment is
maintained.
Recharge Lithiunn Bromide - Recharge lithium
bromide when the purge exhaust bottle becomes
filled.
PROCEDURES
1. Open the exhaust valve and allow solution to
be forced back into the purge,
2. Close the exhaust valve when the level nears
the end of the tube. Do not allow air to be
drawn into the tube.
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